Scottish Natural Heritage. Integrated Pest Management in Nature Conservation Handbook

Transcription

1 Scottish Natural Heritage Integrated Pest Management in Nature Conservation Handbook

2 Edited by SNH Prepared by: Sarah Cook, Steven Tompkins & Nigel Critchley ADAS UK Ltd Battlegate Road Boxworth Cambridge CB23 4NN Year of publication: May 2014 It is the responsibility of the user to check that any plant protection products listed remain and are fully authorised for use. Our guidance is not legally binding nor does it constitute an open ended endorsement of a particular product or chemical, it is intended for guidance only and it is the end users responsibility to check before use on the status of any products.

3 Contents Part 1 IPM in nature conservation 1.1 Introduction Vegetation, pest and disease management IPM Framework Part 2 Protocols for Invasive Non-native Species 2.1 IPM protocol for the control of Japanese knotweed (Fallopia japonica) IPM protocol for the control of giant hogweed (Heracleum mantegazzianum) IPM protocol for the control of Himalayan balsam (Impatiens glandulifera) IPM protocol for the control of freshwater macrophytes Part 3 Protocols for the management of other species 3.1 IPM protocol for the control of creeping thistle (Cirsium arvense) IPM protocol for the control of ragwort (Senecio jacobaea) IPM protocol for the control of bracken (Pteridium aquilinum) IPM protocol for the control of rushes (Juncus spp.) IPM protocol for the control of purple moor-grass (Molinia caerulea) on heather moorland IPM protocol for the control of scrub Part 4 Other pest, disease and vegetation management 4.1 Vegetation management around visitor facilities Forestry Appendices 1. Legislation for chemical control Herbicide application methods Example of an IPM process Integrated Pest Management in Nature Conservation 3

4 Part 1 IPM in nature conservation Integrated Pest Management in Nature Conservation 4

5 1.1 Introduction Over recent years the quantity of pesticides used in agriculture and forestry has reduced, and many of the more toxic and environmentally damaging products have been withdrawn. In nature conservation, non-chemical control of weeds, pests and diseases has usually taken priority and pesticide use has always been low, but occasionally there is a need to apply a pesticide for ecological gain. Recent EU legislation requires that the conditions are created for the implementation of Integrated Pest Management (IPM) principles by all professional users of pesticides and that pesticide use is minimised in protected areas The aims of this handbook are to: 1. present Integrated Pest Management (IPM) principles in the context of nature conservation; 2. encourage site managers to adopt an IPM approach to minimise use of chemicals and protect the environment; 3. provide a set of protocols and sources of further information for specific issues most commonly encountered in Scotland; and 4. provide the basis for making decisions about non-chemical and chemical options for control EU and UK legislation The Sustainable Use Directive (2009/128/EC) was published in November 2009 and came into effect on 14 June The directive sets a framework for Community action to achieve sustainable use of pesticides. One of the requirements is to take all necessary measures to promote low pesticide input pest management, where priority should be given to non-chemical methods. The directive states that government should: establish, and support the establishment of, the conditions needed to implant IPM; ensure general principles of IPM are implemented by all professional users by 2014; and ensure that the use of pesticides is minimised or prohibited in certain specific areas, which includes protected areas. Pest in Integrated Pest Management refers to all harmful organisms including pests (e.g. insects), diseases and weeds. The Directive was transposed into UK legislation on 18 July 2012 when the UK Plant Protection Products (Sustainable Use) Regulations 2012 came into force. Integrated Pest Management in Nature Conservation 5

6 1.1.2 Principles of IPM Integrated pest management (IPM) has its origins in horticulture and agriculture and is part of the conceptual framework for Integrated Production (IP). This concept was developed in 1976 by the International Organisation for Biological and Integrated Control of Noxious Animals and Plants (IOBC). The concept is based on the use of natural resources and regulating mechanisms to replace potentially polluting inputs. Preventive agronomic measures and biological/physical/chemical methods are carefully selected and balanced taking into account the protection of health of users, consumers and the environment. The principles and objectives of IP can be found in Boller et al (2004). IPM is not an off-the-shelf package but is an approach that is knowledge intensive, emphasising the importance of expertise and knowledge about ecological and biological systems dependent upon local conditions and the cropping situation. Prevention is highlighted, stressing the need to grow a healthy crop using resistant varieties, maintaining a fertile soil and nutrient balance and ensuring the presence of natural enemies. The use of pesticides ranges from minimal use, to biopesticides, selective pesticides over broad spectrum, and quickly degradable pesticides over persistent ones. The Food and Agriculture Organisation has proposed the following definition (FAO, 2011): Integrated Pest Management (IPM) means the careful consideration of all available pest control techniques and subsequent integration of appropriate measures that discourage the development of pest populations and keep pesticides and other interventions to levels that are economically justified and reduce or minimize risks to human health and the environment. IPM emphasizes the growth of a healthy crop with the least possible disruption to agro-ecosystems and encourages natural pest control mechanisms. In sites managed for nature conservation, the main objective will be the maintenance and enhancement of the particular features of conservation interest. Although the principles of IPM were developed for horticulture and agriculture where the main objective is crop production, many of the same principles can also be applied at sites where nature conservation is the primary objective About this guide A general framework is provided showing the stages to be followed in implementing IPM in nature conservation. A series of protocols follows along with a worked example, which can be used to make decisions about the optimum IPM approaches for particular weed or vegetation management issues, and draws on existing guidance. The protocols are not meant to replace detailed guidance documents on vegetation management or herbicide use, which remain essential reading, but to complement these by providing an IPM framework. Links to available guidance are provided. The general framework could also be used to produce a protocol or pest management plan for individual circumstances, including additional organisms not covered in this handbook. Integrated Pest Management in Nature Conservation 6

7 The availability and approval of herbicides for chemical control change frequently. Protocols will be updated to reflect changes in chemical approvals and as new information is available on non-chemical methods of control. The storage and use of pesticides are controlled under current legislation. Further details of the legislative framework for chemical control are in Appendix 1. Information on application methods is provided in Appendix 2. The use of pesticides will present a risk to non-target species. Pesticide users must carry out a risk assessment and ensure that these risks do not exceed the benefits. If pesticides are used, every reasonable action must be taken to minimise risk References and sources of information Boller E.F., Avilla J., Jörg E., Malavolta C., Wijnands F. & Esbjerg P. (2004) Integrated Production: Principles and Technical Guidelines, 50 pp. Edited by, IOBC WPRS Bull. Vol. 27 (2), ISBN Radcliffe E. B., Hutchison W. D. & Cancelado R. E. [eds.] (2011) Radcliffe's IPM World Textbook University of Minnesota, St. Paul, MN. Accessed 19 September 2011 FAO (2011) Definition of IPM OECD (1998) Report of the OECD/FAO Workshop on Integrated Pest Management and Pesticide Risk Reduction Neuchâtel, Switzerland 28 June-2 July OECD SERIES ON PESTICIDES Number &doclanguage=en Integrated Pest Management in Nature Conservation 7

8 1.2 Vegetation, pest and disease management Background In nature conservation, if pests or diseases or some plant species pose a threat to the conservation interest of a site, the management plan might need to include measures to control them or prevent their occurrence. Measures might also need to be taken to control organisms to prevent them from spreading to adjacent land, for example if there is a risk of weeds such as ragwort (Senecio jacobaea) dispersing from the site to agricultural land. In many cases, there will be a need to balance the costs and benefits of controlling a potential threat to the conservation interest of a site and any threat to adjoining land. For example, creeping thistle (Cirsium arvense) is a valuable pollen and nectar source for invertebrates and seed source for granivorous birds but also has high dispersal capability and can outcompete other plants in species-rich grassland. In this respect, nature conservation differs from agriculture and commercial forestry as there is a greater emphasis on the need to balance multiple objectives, rather than having a single overriding objective of improving the productivity of a food or tree crop Types of threats The main issues in nature conservation where pesticides might be used will be concerned with vegetation management. Other problems with invertebrate pests and diseases might also occasionally arise although action will not always be necessary. For example, heather beetle (Lochmaea suturalis) can affect stands of heather (Calluna vulgaris) but there is currently no completely effective method for controlling the insect and heather plants in well-managed moorland will usually recover from an outbreak. Similarly, native trees are subject to attack by a range of invertebrates but pest control action will rarely be necessary in a nature conservation situation. For example, the bird-cherry ermine moth (Yponomeuta evonymella) can strip the foliage from bird cherry (Prunus padus) but trees will usually recover without any specific action being taken. Another organism of particular concern is the fungal pathogen Phytophthora, which can affect a wide range of tree and other woody species. Phytophthora outbreaks are difficult to control. For sources of information on pests, diseases and vegetation management in forestry, see Section 4.2. Some wild mammals can also be a threat to nature conservation interests in some circumstances. Methods of control will be predominantly non-chemical for some e.g. deer, while in others chemical control may be an option. Wild mammals are not covered in this guide Invasive non-native species vs native species It is important to make the distinction between the need to control invasive nonnative species and the need to reduce the incidence or abundance of native species that are otherwise an acceptable or even desirable component of the ecosystem. Non-native species become invasive when they gain a competitive advantage over other species already present on a site (e.g. Japanese knotweed (Fallopia japonica), which can outcompete most native herbaceous plant species) or are Integrated Pest Management in Nature Conservation 8

9 able to colonise areas not otherwise occupied by other species (e.g. Himalayan balsam (Impatiens glandulifera), which can colonise bare mud). Species most likely to become invasive are those with an intrinsic capability for rapid dispersal, colonisation and spread, which is further enhanced by isolation from their natural predators, diseases and competitors. These effects can also be exacerbated by climate change if the invasive species is well suited to the changing environment. On nature conservation sites, invasive non-native species can reduce populations of other species by direct competition and can alter entire ecosystems. In such cases, the aim will normally be to eradicate the organism, or at least to reduce or maintain its population at a level whereby it no longer poses a threat to the condition of the site or to adjacent land. Under the Wildlife and Natural Environment Scotland Act 2011 (WANE), it is an offence to plant or cause to grow in the wild any non-native plant species. In some situations, native species might need to be controlled if their population is at a level whereby the nature conservation objectives of the site are being compromised. This can occur as a result of inappropriate management practices having been applied historically, or other factors such as adjacent land management or climate change. Native species that might require control include some that, in normal circumstances, form habitats with significant conservation value in their own right (e.g. stands of scrub or bracken (Pteridium aquilinum)). Species that are not a normal component of the habitat on the site but have colonised recently as a result of inappropriate management might also be the subject of control (e.g. where creeping thistle or ragwort has colonised disturbed grassland). For native species, control will not be the default action but a decision will need to be made on a site by site basis, according to the conservation objectives for the site and what is an acceptable threshold level of the species. Even in the case of recent colonisers, any threat to the habitat or to adjacent land will need to be balanced against their value as a resource for other wildlife. Pest management in a nature conservation context can therefore encompass a number of strategies ranging from eradication of a damaging invasive non-native species to careful management of a natural component of the ecosystem in order to shift the balance in favour of other species Issues to consider The first objective is to prevent a problem from developing but there will inevitably be situations where this cannot be prevented. A key to prevention will be to maintain the habitat in favourable condition and to follow codes of good management practice, such as those set down for farming, woodland management or red deer management. If control is needed, there is a general presumption against chemical control as a first option. The first option is therefore to consider non-chemical control methods. For example, where relatively small numbers of weed plant species are involved, uprooting by hand or machine might be carried out. These methods can allow the selective removal of vegetation but can be slow and expensive and might be limited by the terrain of the area to be treated. If there are large quantities of vegetation to remove, techniques such as regular cutting or grazing might be more effective. Treatments will usually need to be applied over a number of seasons. Integrated Pest Management in Nature Conservation 9

10 1.2.5 Costs There are circumstances where use of chemicals will be necessary to achieve the objectives. This will usually be where non-chemical methods are ineffective or difficult to apply due to limited access or availability of labour or equipment. In all cases, it will be necessary to achieve the best balance taking account of efficacy, cost and safety of the various options. On designated sites, there are restrictions on the type of operations that can be carried out and this will also need to be taken into consideration. Within IPM the use of herbicides is not prohibited but their use is restricted to situations where they give the greatest benefit for the least cost both financially and ecologically. Their use is probably optimal when used in combination with nonchemical methods of control. Options for limiting the effect on non-target vegetation include selective application (e.g. by spot treatment or weed wiper) or use of selective herbicides. It might also be necessary to take public perceptions into account because of objections to the use of chemicals at sites frequented by visitors. In deciding on a control strategy, it will also be necessary to consider the wider effects on the site and particularly any likely impact on other species, ecosystem processes and the overall conservation value of the site. Any remedial action after control measures are carried out will also need to be planned and implemented. For example, if elimination of a weed species results in an area of bare ground being created, it is essential to ensure that it is revegetated by a plant species or assemblage appropriate to the conservation objectives, and not recolonised by the weed itself or other less desirable species. The main aims of site management are to maintain or improve the features of conservation interest (habitats or species populations). Each situation will therefore need to be assessed individually and decisions tailored to the particular circumstances. Nature conservation sites are dynamic systems, changing in response to the prevailing environment including weather, climate, pollution and landscape structure, and anthropogenic activities such as land use, management practices and visitor pressure. Pest management decisions will therefore need to be reviewed constantly both in the short-term (e.g. days or weeks within a single growing season) or long-term (e.g. decades as habitat condition changes). In most cases therefore, there will be a continuing process of assessment and monitoring rather than a single, one-off treatment. Cost of treatments will be largely dependent on individual situations. In general, labour intensive methods such as hand pulling, cutting or spraying will be economical for small areas or where the weed population is small. For larger populations, mechanical methods will be more economical. Standard costs are available which can be used as a general guide, although actual costs will be strongly influenced by site accessibility and terrain. For example, standard costs are specified for support under the Scottish Rural Development Programme (SRDP) 15. The National Association of Agricultural Contractors provides contracting rates for operations including grass topping and cutting, spraying and all-terrain 15 Integrated Pest Management in Nature Conservation 10

11 vehicle spraying, in addition to hourly rates for tractor and driver hire (National Association of Agricultural Contractors 16 ). Standard rates used in the SRDP for own tractors, vehicles and labour are also available. Operations on nature conservation sites will often be more difficult than on agricultural land and rates are likely to be correspondingly higher References and sources of information BCPC (2006) Small scale spraying. BCPC. ISBN X. Matthews, G.A. (2000) Pesticide Application Methods 3rd Edition Blackwell, Oxford SEE (2006) Pesticides: Code of Practice for Using Plant Protection Products in Scotland The UK Pesticide Guide (annually updated) Integrated Pest Management in Nature Conservation 11

12 1.3 IPM Framework IPM depends upon understanding the ecological processes and manipulating key factors to reduce the likelihood of infestations occurring or to reduce populations below an acceptable threshold. A key part of IPM is to use ecologically sustainable methods based primarily around preventative measures and non-chemical control. Use of selective chemicals can also be considered. The overall aim is to develop sustainable methods that cause minimal ecological disturbance. The framework below has been developed from decision trees suggested by Radcliffe et al. (2011) and EPA (2011). Recording decisions year to year may help inform future responses a decision record form is provided on the next page and is also available on [link]. A worked example can be found in Appendix 3. Table 1: A simple framework for IPM in nature conservation Monitor and Identify Threats Monitor for harmful organisms and identify them accurately, so that appropriate control decisions can be made in conjunction with action thresholds. Prevention Prevent dispersal of the harmful organism on to the site. The main strategy will be to manage the site to prevent conditions developing that are conducive to colonisation and spread of the organism. Remove or limit sources of colonisation from the surrounding area Ensure continuing public awareness. Set an Action Threshold Set an action threshold, a point at which populations or environmental conditions indicate that control action must be taken. For some species or circumstances there may be no tolerance. Control Once monitoring, identification, and action thresholds indicate that control is required, and preventive methods are no longer effective or available, evaluate the proper control method both for effectiveness and risk. Consider effective, less risky controls first (e.g. mechanical control). If this or further monitoring indicates that these controls will not work/are not working, then additional control methods might be employed, such as targeted spraying of pesticides. Broadcast spraying of non-specific pesticides is a last resort. Re-evaluation Short-term Was the management decision correct and did the action have desired results? How much has the situation changed from last week/yesterday? New judgments are required. Long-term What worked well during the season or in previous years, and what did not? Protocols for the control of specific Invasive Non-Native Species and for the management of other species can be found respectively in Part 2 and Part 3 of the Handbook. Integrated Pest Management in Nature Conservation 12

13 Decision recording form (Once completed, keep this form for future reference.) Site/Location.. Protected area name if applicable... Decision-making process Completed by Date.... What is the issue? What course of action should be followed? Tick as appropriate Take no action Do not control and monitor situation Control Explain reason for choice, e.g. area of target plant cover. Refer to relevant protocol. Which type of control is most suitable? Tick as appropriate. Which chemical and/or non-chemical method(s) is most suitable? Non-chemical Chemical A combination of chemical and non-chemical Explain reason for choice of control method. Refer to relevant protocol. This decision recording sheet was adapted from Willoughby I et al (2004) Reducing pesticide use in forestry: a practice guide, Forestry Commission/Forest Research, Edinburgh. Integrated Pest Management in Nature Conservation 13

14 Re-evaluation Completed by Date.... Did the action taken have the desired results? If not, describe the outcomes. If control was undertaken, did it work well? If not, describe the outcomes. What were the advantages and disadvantages of the control method(s)? Did the control method have any beneficial/detrimental effect on the conservation interest of the site? Note any effect on the conservation interests. If the desired results were fully not achieved, what action was then taken? Will preventive measures be implemented? Note measures to be taken. Integrated Pest Management in Nature Conservation 14

15 Part 2 Protocols for Invasive Non-native Species Integrated Pest Management in Nature Conservation 15

16 2.1 IPM protocol for the control of Japanese knotweed (Fallopia japonica) Background Crown Copyright GB non-native species secretariat Japanese knotweed (Fallopia japonica) is an invasive non-native species (INNS) Since its introduction in the mid-nineteenth century it has spread throughout the UK particularly along watercourses, road and rail networks and urban areas. Sometimes it is present on the edge of arable fields or in other places where garden waste or topsoil has been dumped. It is not susceptible to native pests and diseases, although a non-native biological control agent, a psyllid bug (Aphalara itadori) has recently been released under licence. It can damage buildings and hard surfaces. Dense summer canopy and persistent stem litter suppress most other plant species. Any plant material or soil contaminated with the plant is classified as controlled waste Identifying the problem Lifecycle Japanese knotweed is a perennial plant that spreads entirely by rhizomes. Even tiny fragments of rhizome can regenerate into new plants. The entire UK population is a single female clone and it produces no seed, although it can hybridise with other species of Fallopia. Integrated Pest Management in Nature Conservation 16

17 Identify In the spring it produces fleshy red tinged shoots. It has branching, hollow, bamboo like stems covered in purple speckles with large heart or spade shaped leaves. The plants grow to a height of 2-3 m and can form dense clumps. Frothy clusters of cream flowers are produced towards the end of July. It dies back between September and November, leaving brown stems. Table 2: Main features of Japanese knotweed Plant Rhizomes Stems Leaves Flowers Seeds An erect plant 2-3 m high. Thick and woody with a knotty appearance, bright orange when cut. Branching, hollow, bamboo-like with purple speckles. Leaves are up to 120mm in length with a flattened base and a pointed tip. Arranged on the stems in a zigzag pattern. Small creamy-white flowers hanging in clusters from the leaf axils appear from late July to October. Does not normally produce seeds Lookalikes Two similar plants also occur. Giant knotweed (Fallopia sachalinensis) is often a similar height (although it can be up to 5 m) but the much larger leaves are distinctive. There is also a smaller compact variety (Fallopia japonica var. compacta) which grows to a height of 1 m. A hybrid of giant and Japanese knotweed (Fallopia x bohemica) also occurs in the Central Belt and other scattered locations but is under-recorded. All lookalikes should be managed in the same way as Japanese knotweed Set a threshold Japanese knotweed is particularly prevalent on brownfield and peri-urban sites; these sites often have value for nature conservation. Infestations are also an extensive and widespread threat to river systems of high nature conservation status. Established stands outcompete native vegetation and could pose a serious threat if established on nature conservation sites. A zero tolerance policy should be followed Japanese knotweed and the law Under section 14 of the Wildlife and Natural Environment (Scotland) Act (2011) (The WANE Act), it is an offence to plant, or otherwise case to grow any plant outside of its native range. Integrated Pest Management in Nature Conservation 17

18 The plant is also classed as controlled waste and as such must be disposed of safely at a licensed landfill site according to the Environmental Protection Act (Duty of Care) Regulations Soil containing rhizome material can be regarded as contaminated and, if removed from a site, must also be disposed of at a suitably licensed landfill site. The owners of sites harbouring Japanese knotweed can also be held liable through common law (i.e. civil action) for costs incurred from its spread into adjacent properties and for the disposal of infested soil off site during development which later leads to its dispersal onto another site Prevention Japanese knotweed does not spread by seed. The plant is spread through rhizome fragments or by cut stems. A plant can regenerate from as little as 10mm (0.7g) of rhizome. Dispersal is mainly by human activity or along watercourses. River catchments In river catchments fragments of stems or rhizomes can be washed into watercourses when water levels are high. Consider controlling Japanese knotweed within the river catchment. Fly tipping Contaminated soil or garden waste dumped illegally can provide a source of infestation. Ensure that all measures are taken to prevent this occurring. Contamination of machinery Ensure that all machinery used on the site is clean and is not transferring small fragments of stem and rhizome Control Non-chemical methods for the control of Japanese knotweed can take up to 10 years to eradicate the weed. Chemical control is usually the preferred method as non-chemical methods may fail to achieve eradication. The decision tree in Figure 1 will assist with selecting the most appropriate technique. Great care needs to be taken with the cut material to avoid further spread Non-chemical methods Non-chemical methods are generally suited to low populations in small areas but present problems of disposal of plant fragments. Integrated Pest Management in Nature Conservation 18

19 Grazing Grazing by horses, donkeys, sheep and goats can keep the plant in check provided previous dead growth is removed. Animals prefer the young shoots as they emerge in the spring and after about June the stems become rather woody. Grazing is not an eradication tool but is helpful in suppressing the plant and reducing spread. However, grazing animals can poach and erode the ground as well as spread plant fragments, so they need to be managed carefully to ensure that they are suppressing the plant and not causing further spread. Pulling Pulling as a method of eradication is only really useful when treating small or new infestations where only a few stems have established. It is a good method to use on sites with native or sensitive species and where the use of herbicides is undesirable. Care should, however, be taken to avoid trampling sensitive flora in the vicinity. Regular pulling will eventually exhaust the rhizome and kill the plant. This is only an effective method of control if it is carried out continually over a number of years and is only effective on small or newly established stands. Plant material accumulated by this technique will need appropriate disposal, which requires significant additional effort. Cutting or Mowing Wherever possible Japanese knotweed should be cut with a single clean cut near the base of the stem. Use a cutting method that prevents fragmentation of the stem. Avoid flail mowing, strimming or similar methods that fragment the stem and rhizomes. Cutting will need to be done at least 4 times per year or every 2-4 weeks during the growing season if it is the only method of control. Cutting annually may take up to 10 years to achieve death of the plant. Plant material accumulated by this technique will need appropriate disposal. Biological control The psyllid bug Aphalara itadori is currently being evaluated under licence as a method of biocontrol for Japanese knotweed Disposal Disposal of cuttings should be done on site either by composting or burning (a licence is required). Stems should be dried on a layer of polythene to prevent rooting and once they become dark brown in colour they cannot regenerate. Dried cut stems can then be safely composted. Pulled stems, which will include crowns, are not suitable for composting. When burning pulled stems, ensure that the crown is in the centre of the fire and is thoroughly combusted. Integrated Pest Management in Nature Conservation 19

20 What area of Japanese knotweed cover is present on the site? High > 5m2 Low < 5m2 Consider use of herbicides with non-chemical methods Attempt control with nonchemical methods Foliar spray Weed wiper/rope wick Stem filling Stem injection NO Hand pulling Cutting Consider further use of herbicides Evaluate chemical control; consider grazing with livestock to control new shoots Review the strategy - has the infestation been controlled? NO Review the strategy - has the infestation been controlled? YES YES Monitor occurrence of infestation and be ready to control if problem returns Figure 1: A decision tree to guide the selection of methods to control Japanese knotweed An alternative method is disposal to landfill; the plant is classed as controlled waste and as such must be disposed of safely at a licensed landfill site according to the Environmental Protection Act (Duty of Care) Regulations Soil containing rhizome material can be regarded as contaminated and, if taken off a site, must be disposed of at a suitably licensed landfill site and buried to a depth of at least 5 m. Integrated Pest Management in Nature Conservation 20

21 Chemical Control Choice of herbicide There are a range of herbicides that can be used to control Japanese knotweed and these are detailed in Table 3. Herbicides should be applied for at least 3 years to stop the plant from growing back. Lack of growth from the rhizomes does not necessarily mean that the plant is dead as they can lie dormant for several years; disturbance of the rhizomes can result in further growth. The best time to apply glyphosate is at flowering in August or September but before the plant begins to die-back. Aminopyralid + fluroxypyr, triclopyr and 2,4-D can be used during the growing season. Glyphosate will kill the plant and others around it. Use of a weed wiper or spot treatment with a hand lance can increase the selectivity of this herbicide. Fitting the hand lance with a guard can direct the spray to the target more accurately. Glyphosate can also be directly injected into the stem. Glyphosate is the only herbicide approved for use near water but permission should be sought from SEPA for use in this situation. Spraying with vehicle mounted equipment should be considered only where there are no species of conservation value which will be affected by the herbicide. Always read the product label prior to using an herbicide Application Methods Foliar sprays A single spray at flowering is the optimum timing. Use of extending hand lances are recommended where plants are 2-3m tall. Spray the underside as well as the upper surface of the leaves. A two spray programme can be followed. The first application is made when the plant reaches 1-1.5m tall, in late May and repeated when any re-growth reaches 1.5m. This technique can be used where stands are particularly dense, or as part of an integrated programme in combination with cutting or mowing or where long lances are not available. Weed wiper, rope wick applicator Applications using a hand held weed wiper are best where treatment of nearby vegetation is to be avoided or for spot treatment of small re-growth. It is a labour intensive method. Glyphosate is best applied to stems at 1-3m height in late summer. Stem filling In certain situations such as on sites with a ground flora of particular value or where the Knotweed is growing close to other plants (e.g. in a hedge), a stem filling technique can be used. This technique requires a high labour input but the herbicide can be more accurately directed. The technique involves cutting the stem and injecting glyphosate in solution with water directly through the top. Integrated Pest Management in Nature Conservation 21

22 Table 3: Japanese knotweed (Fallopia japonica) - possible herbicides for its control. Herbicides Uses Application methods Timing 2,4-D Amenity grassland, Grassland, Managed amenity turf Foliar spray via vehicle mounted or hand-held equipment Apply from May to October but more effective in the early season when growing actively. 2,4-D + dicamba + triclopyr Grassland, Amenity Grassland, Forest, Natural surfaces not intended to bear vegetation Foliar spray via vehicle mounted or hand-held equipment Apply after first flush of spring growth when plants are 1-2 m high, typically between July and September. A repeat treatment may be necessary. Aminopyralid + fluroxypyr Amenity grassland, Grassland Foliar spray via vehicle mounted equipment or hand-held equipment (Synero only) Treat when actively growing. Control is improved with spot treatment. Glyphosate Unwanted vegetation, Grassland, Forest, Natural surfaces not intended to bear vegetation, Amenity vegetation, Land immediately adjacent to aquatic areas Foliar spray via vehicle mounted or hand-held equipment For a single spray the optimum timing is at flowering. Spray the underside as well as the upper surface of the leaves. Two sprays -Spray plants at 1-1.5m tall, in late May and repeat on any re-growth once they reach 1.5m again. This technique can be used where stands are particularly thick, as part of an integrated control programme or where long lances are not available. Weed-wiper Useful where treatment of nearby vegetation is to be avoided, spot treatment of small regrowth or stems <8mm. High success rates, but labour intensive. Treat when1-3 m high in late summer Integrated Pest Management in Nature Conservation 22

23 Herbicides Uses Application methods Timing Glyphosate Stem treatment. Spot gun or stem injection Stem Filling Suitable for situations where the knotweed is growing in close proximity to valuable plants. Stems (>8mm) are cut and glyphosate in solution is placed in the top of cut stems. Treat before senescence from September through October. Stem injection Suitable for treating small stands, particularly by water, new invasions and to tidy up escapes from eradication control programmes. Glyphosate is injected directly into the stem (>8mm). Apply to flowering stems from late summer through October. Triclopyr Unwanted vegetation Foliar spray via vehicle mounted or hand-held equipment. Do not apply by hand held applicator rotary atomiser. May to October when weeds are actively growing. Best control from early season treatment. Stem injection The JK injection tool uses a needle to inject directly into the stem rather than cutting the stem down. This method can be used to treat small stands, particularly by water, new invasions and to tidy up escapes from eradication control programmes. Apply to flowering stems from late summer through October for best results. Integrated Pest Management in Nature Conservation 23

24 Effect on non-target species Aminopyralid, fluroxypyr, triclopyr and 2,4-D are selective and do not harm grasses. When applying triclopyr to areas with trees, protect them with a tree guard and direct spray away from leader shoots. Glyphosate is a non-selective herbicide that kills most plants including grasses. Glyphosate is suitable for use near water. Always check the product label Re-evaluation and monitoring Continue to monitor the area for signs of regeneration from vegetative fragments following control, and the development of new stands in the vicinity, especially along watercourses. Re-evaluation should be carried out in the context of informing a control programme for the next year. Points to consider are: Was the management decision correct and did the action taken have the desired results? If a treatment was used, did it work well? What were the advantages and disadvantages? Did the treatment have any beneficial or detrimental effect on the conservation interest of the site? Where the infestation on site constitutes a high risk, chemical methods may need to be considered if a programme of non-chemical control has either not been effective to ensure the desired eradication, or if non-chemical methods are impracticable for the site (for example, labour requirements, access etc). Monitoring is key to an effective strategy. Even if eradication has been achieved, the site and nearby areas should be monitored to ensure the plant does not recolonise in the future References and sources of information Environment agency (2006) The knotweed Code of Practice managing Japanese knotweed on development sites GB Non-Native Species Secretariat. Rivers and Fisheries Trusts of Scotland - Invasive non-native species (terrestrial plants, aquatic plants & algae, invertebrates, vertebrates): Scottish Government (2012) The Code of Practice on Non Native Species Scottish Environment Protection Agency website page on non-native species The Tweed Forum (20-) The Tweed Invasives Project. The UK Pesticide Guide (annually updated) The Voluntary Initiative Environment Information Sheets on pesticides: Integrated Pest Management in Nature Conservation 24

25 2.2 IPM protocol for the control of giant hogweed (Heracleum mantegazzianum) Background RPS group plc Giant hogweed (Heracleum mantegazzianum) is an invasive non-native species (INNS) introduced to the British Isles from South West Asia around A very large biennial/perennial commonly located in damp places and by streams and rivers. Suppresses other vegetation and causes erosion risk. Sap produces severe skin irritation Identifying the problem Lifecycle It is a biennial or short-lived perennial, initially a large basal rosette which often takes up to four years to reach its full height of metres and then flowers. Flowering occurs during May to July. The plant overwinters as a large fleshy taproot. Under conditions unfavourable to flowering and seed production, plants can survive for up to 12 years. Plants reproduce by seed only. Integrated Pest Management in Nature Conservation 25

26 Identify Giant hogweed is easily identified at the flowering stage on account of its size, although hybrids with common hogweed (H. sphondylium) can occur and may be smaller in size. The rosette stage can be up to 1m wide with large, dark green deeply lobed leaves with reddish purple-blotched leaf stalks. Table 4: Main features of Giant Hogweed Stem Leaves Flowers Seeds Has a reddish purple blotchy ribbed stem with sparse spiky hairs on the ribs, usually unbranched. The stem is also hollow up to 5-10 cm in diameter. Dark green deeply lobed leaves, spiked at the end up to 1.5 m wide, with reddish purple spotted leaf stalks. White flowers with petals up to 12mm long are arranged in flattopped umbrella like clusters. These umbels can be up to 50 cm across. Seeds are flattened and oval with a broadly rounded base. Each plant is capable of producing 50,000 seeds every year. Seeds can remain dormant in the soil for up to15 years Lookalikes Giant hogweed closely resembles cow parsley (Anthriscus sylvestris), wild angelica (Angelica sylvestris), hemlock (Conium maculatum) and common hogweed (Heracleum sphondylium). Although similar, giant hogweed is much bigger than any of these species Impacts of giant hogweed Hairs on the outside of the stems and poisonous sap on the inside of the stems and leaves can cause severe irritation. The sap reacts with the skin and makes the skin sensitive to ultra-violet light, though no pain or irritation is felt at the time of contact. Any subsequent exposure to sunlight can cause the skin to burn and will result in large, watery blisters that do not become evident until 15 to 20 hours following contact, by which time the damage has been done. Blisters may develop into purplish or blackened scars and could persist as recurrent photo-dermatitis long after exposure. Contact with the eyes can lead to temporary (or, in some cases, permanent) blindness. Giant hogweed is very competitive because of its large size and rapid growth rate. It outcompetes native vegetation for space and resources, thereby reducing plant and invertebrate diversity. When the plant dies back in the winter the bare areas are more susceptible to erosion from rainfall and flooding. The death of the stem loosens the surrounding soil, so that in high density stands, it can result in whole sections of riverbank being washed out. Seed production is high and they are easily dispersed by water especially during a flood. Seeds washed downstream can rapidly infest bare areas of bank. Humans can also facilitate their distribution by seeds sticking to car tyres, umbels being taken for decoration purposes and Integrated Pest Management in Nature Conservation 26

27 attachment to clothes. Likewise, seeds can attach to animal fur. Wind dispersal can occur when seeds are blown over frozen or snowy surfaces Set a threshold Giant hogweed is an invasive, non-native plant. Because of the risks to public and its competitive effect on native vegetation, the threshold for giant hogweed should be zero Giant hogweed and the law Under section 14 of the Wildlife and Natural Environment (Scotland) Act (2011) (The WANE Act), it is an offence to plant, or otherwise case to grow any plant outside of its native range. The plant is also classed as controlled waste according to the Environmental Protection Act (Duty of Care) Regulations 1991 and must be removed from the site for disposal, unless otherwise agreed with SEPA. Material for disposal must be removed by a SEPA licensed haulier to a licensed or permitted landfill site. All containers or bags containing giant hogweed or infested soil leaving the site must be covered to avoid spread along public roads Prevention The main strategy for preventing establishment is to maintain vegetation cover. If plants establish, prevent seed spread by controlling the plants before the flowering stage. Monitor for the presence of plants during the late spring and summer as the flowering form or as large rosettes. Giant hogweed prefers open undisturbed sites with abundant light but can be present in more shady areas. Infestations primarily occur along river or streams Control A giant hogweed control strategy should aim to kill existing plants and deplete the remaining seedbank to ensure further problems do not develop. To this end a control strategy should last as long as the seedbank remains viable. Protective water-resistant clothing and protective glasses or goggles must be worn when working with giant hogweed. This is due to the risk of skin contact with splashes of toxic sap and sap coated fragments of the plant. The options for control consist of both non-chemical and chemical methods. Control might need to be repeated over several seasons as it will take some time before the seedbank is exhausted and no new plants appear. Chemical control should only be used where non-chemical methods have failed to achieve the desired level of control. The decision tree in Figure 2 will assist with selecting the most appropriate technique. Integrated Pest Management in Nature Conservation 27

28 What is the size of the giant hogweed infestation to be controlled? Large- >100 individuals Small - a few individuals Is it possible to plough or excavate Giant Hogweed on site? YES Is immediate control required? NO YES NO Is immediate control required? Hand pulling Hand cutting Root cutting NO YES Mechanical mowing or flailing with vehicle. Continue to monitor re-growth and control when necessary. Follow up with grazing by livestock if suitable for site. Consider use of herbicide for immediate plant kill foliar spray, weed wiper, stem injection Monitor re-growth and control subsequent plants. Plough Excavate Monitor re-growth and control subsequent plants. YES Monitor occurrence of infestation and be ready to control if problem returns. Review the strategy- has the infestation been controlled? NO Re-assess problem from start and plan a new approach of control measures. Figure 2: A decision tree to guide the selection of methods to control Giant Hogweed Integrated Pest Management in Nature Conservation 28

29 Non-chemical Non-chemical controls are generally more labour intensive and more suited to smaller areas. Where stock is present the grazing removal period is much shorter than with chemical control. In highly sensitive environments, where using pesticides may incur a risk to surrounding flora, non-chemical methods may be the only feasible option. Ploughing Where a site is suitable for repeated ploughing, with no species of interest that may be damaged by the process, it can be a highly effective control measure. A plough will both cut the taproot of giant hogweed and bury the seed at a depth that will inhibit emergence. As ploughing creates a high level of disturbance on sites, it is only suitable for large, non-sensitive sites where other valuable vegetation does not exist. Excavation Excavation can be an effective immediate control strategy to completely remove plants, and if carried out correctly, also remove the seedbank. Removing the seedbank will require the likely dispersal distance of the seeds from plants to be predicted accurately. Excavation will cause a high level of disturbance, and should only be carried out in non-sensitive areas. Root cutting Cutting should be done in the early spring (April-May) before the leaves are too large. Cut the taproots approximately cm below ground level using a sharp blade, aiming to separate the stem base from the root. Cut parts should be removed and left to dry or disposed of in the correct manner. Check for regrowth during June - July and treat any plants that were missed or have resprouted. Whilst root cutting can be effective for a small stand of plants, the method is labour intensive and needs to be coupled with long term management of the seedbank. Seed head removal Cutting the head of the plant should be done early in the year when plants are small and have not already set seed. In some cases old plants may also have heads with a large number of seeds on them, but the majority will drop by the end of December. When cutting plants, the best option is to bag the seed head, then cut the stem below. This can be done with a standard domestic bin bag and aims to prevent seeds from falling. It is important to dispose of seed heads appropriately after cutting as they may still be viable if left on site. Mowing Cutting plants at the vegetation stage will not kill them, rapid regrowth will occur from the base and cutting should be repeated 2 or 3 times during the growing season. Cutting the plants at mid flowering will prevent the production of new seeds, although if cut too early it will stimulate production of secondary stems that can also flower. Giant hogweed stores its energy in the taproot, which allows the plant to develop. A consistent mowing regime will eventually kill the plant by preventing the leaves from fully developing, and exhausting the energy in the taproot. In some cases, consistent mowing will be needed over a number of years Integrated Pest Management in Nature Conservation 29

30 and therefore should only be used where control over a long period is acceptable. Once cut the plant will vigorously regrow, so monitoring of re-growth is needed to provide follow up treatment in a timely manner. Grazing Grazing by sheep, cattle, pigs or goats during the growing season will suppress growth but does not eradicate the weed. Grazing has similar effects to mowing, with repeated new growth from damaged plants. Akin to mowing, this control strategy often will take a number of years to ensure complete eradication. However, animals are susceptible to the toxic effects of giant hogweed, particularly those with bare and un-pigmented skin. Selecting animals with pigmentation of bare skin can reduce inflammation of mucous secreting membranes. Symptoms of poisoning are skin inflammation, and blistering around the mouth, nostril, eyes and ears. Remove affected animals from the area temporarily. The effects are transitory and the animals show no long-term side effects. Disposal Giant hogweed material is classed as a controlled waste, and if taken off site must be disposed of in the correct manner. The three most common methods are burial on the site of control, incineration or disposal to a licensed landfill site Chemical control Choice of herbicide The optimum application timing is before flowering, ensuring that all foliage is well covered. If all plants are controlled then the area should be monitored for the following 2-3 years. Overall sprays or spot treatments with a hand-held lance containing glyphosate or triclopyr should be used in early spring when plants are 20-50cm. A repeat application may need to be made before the end of June to target newly germinated seedlings. Stem injection of glyphosate has been used as a technique in the Nith catchment, and within 2 weeks treated plants were weakening and dying back. Glyphosate will kill the plant and others around it. Use of a weed wiper or spot treatment with a hand lance can increase the selectivity of this herbicide. Fitting the hand lance with a guard can direct the spray to the target more accurately. Glyphosate can also be directly injected into the stem. Glyphosate is the only herbicide approved for use near water but permission should be sought from SEPA in this situation. Spraying with vehicle mounted equipment should be considered only where there are no species of conservation value which will be affected by the herbicide. Always read the product label prior to using an herbicide. Integrated Pest Management in Nature Conservation 30

31 Effect on non-target species Non-selective herbicides such as glyphosate can kill all species they come in contact with. Triclopyr is a selective herbicide, being safer to use with grasses, but most woody and broad-leaved plants are susceptible. When applying triclopyr to areas with trees, protect them with a tree guard and direct spray away from leader shoots. Table 5: Giant hogweed (Heracleum mantegazzianum) - possible herbicides for its control. Herbicides Uses Application methods Timing Glyphosate Unwanted vegetation, Grassland, Forest, Natural surfaces not intended to bear vegetation, Amenity vegetation, Land immediately adjacent to aquatic areas Foliar spray via vehicle mounted or hand-held equipment. Spray when foliage has reached 20-50cm high in late spring, continue through the summer. More than 1 application will be necessary. Follow-up sprays needed to treat seedlings in future years. Weed wiper Timing as for sprays, useful in mixed populations. Stem injection Suitable for treating small stands, particularly by water. Glyphosate is injected directly into the stem. Apply to extended stems before seed set. Triclopyr Unwanted vegetation Foliar spray via vehicle mounted or hand-held equipment. Do not apply by hand held applicator with rotary atomiser. Apply during April-May when the weed is actively growing. More than 1 application will be necessary. Follow up sprays needed to treat seedlings in future years Re-evaluation and monitoring Check treated plants for regrowth and continue to monitor the area for regeneration of seedlings in the vicinity of the original infestation, especially along watercourses. Re-evaluation should be carried out in the context of informing a control programme for the next year. Points to consider are: Was the management decision correct and did the action taken have the desired results? Integrated Pest Management in Nature Conservation 31

32 If a treatment was used, did it work well? What were the advantages and disadvantages? Did the treatment have any beneficial or detrimental effect on the conservation interest of the site? Where the infestation on site constitutes a high risk, chemical methods may need to be considered if a programme of non-chemical control has been ineffective or impracticable for the site (for example, due to labour requirements, access, etc.). Monitoring is key to an effective strategy. Even if eradication has been achieved, the site and nearby areas should be monitored to ensure the plant does not re-colonise in the future References and sources of information Nielsen, C., H.P. Ravn, W. Nentwig and M. Wade (eds.), The Giant Hogweed Best Practice Manual. Guidelines for the management and control of an invasive weed in Europe. Forest & Landscape Denmark, Hoersholm, 44 pp. Giant Hogweed Management in the United Kingdom by Olaf Booy and Max Wade 2007, published by RPS Group plc ISBN Booy, O. Wade, M. & White, V. Giant Hogweed Identification Sheet.: GB Non-native Species Secretariat website. Rivers and Fisheries Trusts of Scotland - Invasive non-native species (terrestrial plants, aquatic plants & algae, invertebrates, vertebrates): Scottish Environment Protection Agency website. Scottish Government (2012) The Code of Practice on Non Native Species The Tweed Forum (20-) The Tweed Invasives Project. The UK Pesticide Guide (annually updated) The Voluntary Initiative Environment Information Sheets on pesticides: Integrated Pest Management in Nature Conservation 32

33 2.3 IPM protocol for the control of Himalayan balsam (Impatiens glandulifera) Background Crown Copyright GB non-native species secretariat Himalayan Balsam (Impatiens glandulifera) is a non-native plant which rapidly colonises areas of river bank and damp ground. It is an annual plant which commonly grows to 2 metres tall, with purplish-pink flowers which appear in June. Once mature, seed pods explode when ripe, scattering seed which is also transported via watercourses. Each plant produces at least 500 seeds which can be propelled up to 7 metres from the parent plant. When found on riverbanks the plant can shade out underlying vegetation causing bank erosion Identifying the problem Lifecycle Whilst Himalayan balsam is only an annual plant, its high level of seed production and vigorous seed dispersal means that it is highly invasive Identify Himalayan balsam is most easily identified by its pink/purple flowers in June/July but is also distinctive at other stages in the life cycle. Integrated Pest Management in Nature Conservation 33

34 Table 6: Main features of Himalayan Balsam Stem Leaves Flowers Seeds Hollow, reddish-translucent stem 5-50 mm in diameter. Usually a single stem but sometimes branched. Leaves are either opposite or in bunches of 3. Shiny and green with a reddish vein running up the middle. Leaf margins separate sharply with teeth on either side. Flowers are either white-pink or red-pink in a bell shape. Average of 3-12 flowers per plant which are cm long. Plants set seeds from mid-july onwards. Explosive dehiscence with fruit capsules exploding at the slightest movement or touch when ripe. The seeds are 4-7 mm in diameter Impacts A number of problems are associated with infestations of Himalayan Balsam. Where the plant occurs on riverbanks, dense stands can shade out low lying native vegetation reducing diversity. In the autumn when the balsam dies back, the bare banks are liable to erosion. Furthermore, with large quantities of nectar production, the plants are specifically attractive to bumblebees, thereby reducing pollination of native plants. Himalayan balsam requires high soil moisture to grow and is only constrained by its susceptibility to frost. It grows on both flat land and steeply sloping banks and can tolerate a moderate level of shade Lookalikes Great willowherb (Epilobium hirsutum) has a smooth stem and round leaves and pink flowers but is a rhizomatous perennial. Touch-me-not balsam (Impatiens nolitangere) inhabits a similar environment to Himalayan balsam but is much more delicate and has yellow flowers. Small balsam (Impatiens parviflora) can also be found on riverbanks but is much smaller with yellow flowers Set a threshold Himalayan balsam is highly invasive due to its vigorous seed spread. In conservation areas, even small infestations should be controlled to prevent potential seed spread. A zero tolerance policy should be set for Himalayan balsam. Due to its invasive nature, leaving just one plant may incur repeated control for up to 18 months (the length of seed viability). High H. balsam present in areas of importance in nature conservation. Present by water bodies which could spread seed. Medium Low H. balsam present in nearby areas, or upstream and likely to infest site. Known to be present in the locality Integrated Pest Management in Nature Conservation 34

35 Himalayan balsam and the law Under section 14 of the Wildlife and Natural Environment (Scotland) Act (2011) (The WANE Act), it is an offence to plant, or grow any plant outside of its native range Prevention Where possible, maintaining dense, closed vegetation will prevent the establishment of Himalayan balsam by suppressing the establishment of seed. However, in many cases, the plant grows on riverbanks, on gravel and areas of river alluvium. In these areas, maintenance of dense vegetation is not possible due to inherent instability of the substrate. In order to control plants before they shed seed, regular inspection of vulnerable areas for the plants should be carried out throughout the year Control Control measures for Himalayan balsam should aim to prevent the plant from flowering and to exhaust the seedbank over time. Most effective control will usually take place before June as the plant develops flower buds, and will last for the duration that seeds are viable in the soil, which is typically up to 2 years. Chemical control is often more practical for high density stands of Himalayan balsam, where hand cutting or pulling would be difficult. Caution should always be taken where potential damage to surrounding vegetation may result from the use of herbicides. Where a few plants are distributed across a large area, hand pulling can be more effective and prevent damage to non-target species. Where herbicides are planned for use near watercourses, prior written permission from SEPA is required. The decision tree in Figure 3 will assist with selecting the most appropriate technique Non-chemical Grazing Grazing can be effective if land populated by Himalayan balsam is not susceptible to erosion (e.g. on bankside vegetation). Grazing is recommended from April right through the growing season and continued until no new growth occurs. Sheep are a good option as they typically graze close to the ground, below the lowest node which will prevent balsam from regrowth and flowering. Cattle can also be used, although different breeds have different grazing requirements related to digestibility and energy content. In all cases, it is wise to first research which breed of animal will be best for the particular site, taking into account factors such as the local climate, range of vegetation and practical aspects (such as fencing and presence of the public). Pulling Himalayan balsam has a relatively small, shallow root system which is easily removed if the plant is pulled firmly from the base. If pulling is not done correctly then the stem can snap, and regrowth will occur. If done in the correct manner pulling can be a very effective strategy where an infestation is relatively low. The Integrated Pest Management in Nature Conservation 35

36 aim of a pulling regime should be to prevent the plant from setting seed; therefore the best timing is when the plant is just developing flower buds. Pulling should be seen as a constant control mechanism, predicated by monitoring of the site in order to tackle any late germinating or small plants that may have been missed in the initial pulling regime. Whilst pulling is labour intensive, it can be an effective strategy and should be favoured over the use of herbicide which may cause damage to other vegetation. The Tweed Forum 17 estimated the costs of hand pulling Himalayan balsam on a 30 mile stretch of river to be in the region of 20,000. Where possible, plants should be burned or composted after pulling up. Cutting Cutting can be done through use of a scythe, machete, flail or strimmer before the flowering stage in June. Plants must be cut at ground level, below the lowest node. Any cuts above the lowest node will lead to regrowth and re-flowering. Cutting too early will promote greater seed production from the plants that re-grow. Similarly, cutting once the seed-heads have formed will simply distribute them, making the problem worse. Cutting more than once a year might be required. As with a pulling regime, close monitoring should determine when cutting is needed again to prevent re-seeding Biological control There are no biological control methods currently available for Himalayan balsam. However research is underway into natural enemies of the plant, including coevolved insects and plant pathogens that could be released in the UK. Potential risks would need to be assessed as introduction of natural enemies might affect native Impatiens noli-tangere in England and specialists dependent on it Chemical control Choice of herbicide The optimum timing of application is before flowering, ensuring that all foliage is well covered. If all plants are controlled then the area should be monitored for the following 2-3 years. Work by the River Tweed Forum has shown that the soft fleshy nature of Himalayan balsam makes it highly sensitive to glyphosate. Dilute concentrations of glyphosate have been found to be effective, and in some cases as well as being a significant cost saving, this can leave non-target vegetation partially intact, helping to prevent further establishment of the balsam. Glyphosate will kill the plant and others around it. Use of a weed wiper or spot treatment with a hand lance can increase the selectivity of this herbicide. Fitting the hand lance with a guard can direct the spray to the target more accurately Glyphosate is suitable for use near water. Permission from SEPA must be sought before treatment. Spraying with vehicle mounted equipment should be considered only where there are no species of conservation value which will be affected by the herbicide in the surrounding area. Always read the product label prior to using an herbicide Integrated Pest Management in Nature Conservation 36

37 Is Himalayan balsam present on site? YES NO Density of infestation YES Present in nearby areas Low density of plants over an extensive area High density of plants over a small or large area NO Repeated hand pulling and/or cutting Consider using a herbicide (weed wiper, foliar spray) Consider running nonchemical methods such as cutting or grazing alongside herbicides to maintain control Continue to monitor adjacent areas for presence of H. balsam Review the strategy: was the infestation controlled? YES NO Density of infestation Low: <10 plants/m2 High: >10 plants/m2 Are species of conservation interest present in the immediate area Weed wiper Selective spraying Spot treatment YES NO Consider spraying with vehicle mounted equipment Figure 3: A decision tree to guide the selection of methods to control Himalayan balsam. Integrated Pest Management in Nature Conservation 37

38 Table 7: Himalayan balsam (Impatiens glandulifera) possible herbicides for its control. Herbicides Uses Application methods Timing Glyphosate Unwanted vegetation, Grassland, Forest, Surfaces not intended to bear vegetation, Amenity vegetation, Land immediately adjacent to aquatic areas Foliar spray via vehicle mounted or hand-held equipment. Weed wiper. Always consult SEPA before use in or near water. Apply before flowering. Effect on non-target species Glyphosate is a non-selective herbicide that kills most plants including grasses Re-evaluation and monitoring Himalayan balsam is likely to regenerate from shed seeds, so continue to monitor the area for young plants, especially on bare ground near the original infestation. When adjacent to a watercourse, pay particular attention to areas downstream. Re-evaluation should be carried out in the context of informing a control programme for the next year. Points to consider are: Was the management decision correct and did the action taken have the desired results? If a treatment was used, did it work well? What were the advantages and disadvantages? Did the treatment have any beneficial or detrimental effect on the conservation interest of the site? Where the infestation on site constitutes a high risk, chemical methods may need to be considered if a programme of non-chemical control has either not been effective to ensure the desired eradication, or if non-chemical methods are impracticable for the site (for example, labour requirements, access etc). Monitoring is key to an effective strategy. Even if eradication has been achieved, the site should be monitored to ensure the plant does not recolonise in the future References and sources of information Beerling, D.J. & Perrins, J.M. (1993) Biological Flora of the British Isles: Impatiens glandulifera Royle (Impatiens roylei Walp.). Journal of Ecology 81, GB Non-native Species Secretariat website. Rivers and Fisheries Trusts of Scotland - Invasive non-native species (terrestrial plants, aquatic plants & algae, invertebrates, vertebrates): Scottish Environment Protection Agency website. Integrated Pest Management in Nature Conservation 38

39 Scottish Government (2012) The Code of Practice on Non Native Species Tweed Forum (2006) The Tweed Invasives Project. The UK Pesticide Guide (annually updated) The Voluntary Initiative Environment Information Sheets on pesticides: Integrated Pest Management in Nature Conservation 39

40 2.4 IPM protocol for the control of freshwater macrophytes Background Crown Copyright GB non-native species secretariat Freshwater macrophytes are a key component of aquatic systems. Invasive species, including some non-native species, can dominate aquatic vegetation. In flowing waters aquatic plants may interfere with water flow (increasing flood risk or impeding drainage), and increase siltation. They can interfere with navigation or recreational use of the water Identifying the problem Freshwater macrophytes in general will sometimes require control to reduce their abundance. Native species will normally be a valuable component of the aquatic habitat but if they show a tendency to dominate the community, control might need to be considered. In contrast, control of invasive non-native species (INNS) should be considered wherever they occur. They can quickly populate water bodies, competing with and shading out native plants. Species of particular concern are Canadian waterweed (Elodea canadensis), Nuttall s waterweed (Elodea nuttallii), New Zealand pygmyweed (Crassula helmsii), curly water-thyme (Lagarosiphon major) and water fern (Azolla filiculoides). Parrot s-feather (Myriophyllum aquaticum) is rare in Scotland at present and floating pennywort (Hydrocotyle ranunculoides) is absent, but both species could establish in the future. Fresh water macrophytes can be divided into three groups (submerged, floating, emergent) that require different approaches to their control Legislation Under Section 14 of the Wildlife and Natural Environment (Scotland) Act (2011) (The WANE Act), it is an offence to plant, or otherwise cause to grow any plant outside of its native range Lifecycle All the species mentioned here are perennial. Their growth begins in early spring as water temperatures rise. Integrated Pest Management in Nature Conservation 40

41 Identify The table below highlights the main features of the seven key invasive non-native species. Group 1: submerged plants foliage does not appear above the surface of the water. Group 2: floating plants plants float on the surface of the water, either freefloating or rooted to the substrate with floating leaves. Group 3: emergent plants a proportion of the foliage of these plants is held above the water surface. Table 8: Main features of key invasive non-native freshwater macrophytes Common name Canadian waterweed Nuttall s waterweed, Esthwaite waterweed Curly water-thyme, curly waterweed, curly pondweed Scientific name Elodea canadensis Elodea nuttallii Lagarosiphon major Group Location Static or slow moving water Static or slow moving water, prefers more nutrient enriched water Static or slow moving water Plant Submerged, rooted in mud Submerged, rooted in mud Submerged, rooted in mud, twice the size of Elodea Stems Long (up to 3m) rounded and branching Long (up to 3m) rounded and branching Long (up to 3m) Leaves Pale green, strap-like stalkless leaves (up to 5.5mm wide) in whorls of 3 (rarely 4 or 5). Not curved or twisted. Pale green, strap-like stalkless leaves (up to 3mm wide) with sharp tips in whorls of 3 (rarely 4 or 5). Twisted and curve backwards to touch the stem. Arranged in a spiral along the stem, strongly curved backwards towards the stem (6-30mm long, 1-3mm wide). Can become encrusted with calcium carbonate. Flowers The tiny white flowers float on the water surface at the end of long stalks The tiny white flowers float on the water surface at the end of long stalks Borne singly in axils of leaves on very long stem (hypanthia) Seeds Does not produce seeds as all plants are female Does not produce seeds as all plants are female Does not produce seeds as all plants are female Integrated Pest Management in Nature Conservation 41

42 Common name Water fern New Zealand pygmyweed Floating pennywort Parrot's feather Australian swamp stonecrop Scientific name Azolla filiculoides Crassula helmsii Hydrocotyle ranunculoides Myriophyllum aquaticum Group 2 1 and and 3 Location Stagnant or slow moving water. All year round growth, damp ground or still water up to 3m deep. Slow moving water on the edges of rivers, in lakes and ditches. Still and slow moving water. Plant Free-floating water fern that resembles a floating moss. Forms dense carpets. Green in the summer but becomes red towards autumn. There are three forms 1) Terrestrial with creeping stems. 2) Emergent with densely packed stems in water less than 0.6m deep. 3) Submerged growing from basal rosette with long sparsely-leaved stems reaching the surface. Emergent or floating on the water surface. There are 2 forms 1) Emergent with bright green to bluegreen colour, feather like leaves at the margins of still and slow moving water. Can be found growing on land when ponds dry out. 2) Submerged is similar in appearance to emergent form, dull green in colour. Stems Branched up to 5cm long. Brown roots hang from the stems. Rigid with leaves in pairs. Fleshy with rooting from the nodes at 4-6cm intervals. Stems grow to 2m tall. Whorls of leaves at regular intervals up the stem. Brown roots present at nodes below water surface. Stem breaks easily. Leaves Very small up to 2.5cm, two-lobed leaves overlap and cover the stem. Small (4-15 mm), light green, varying from long and narrow in deep water to slightly widened with sharp or bluntish tips in air. Leaf tip is not notched. Leaf bases are joined forming distinctive 1mm collar around the stem. Floating or emergent, shiny kidney shaped to round deeply lobed leaves with crinkled edges up to 7 cm across (sometimes up to 18cm). Finely divided, feathery appearance in whorls of 4-6. Flowers None. White with 4 petals, appear singly in stalks up to 8mm long and grow in the axils of the leaves in summer. Tiny white flowers are rarely seen. Small, white (2mm) and inconspicuous at the base of leaves. Integrated Pest Management in Nature Conservation 42

43 Common name Water fern New Zealand pygmyweed Floating pennywort Parrot's feather Australian swamp stonecrop Scientific name Azolla filiculoides Crassula helmsii Hydrocotyle ranunculoides Myriophyllum aquaticum Seeds Reproduces via spores. 4 per flower but unable to set viable seed in the UK. Scarce but some sites have been colonised via seed spread. Does not produce seeds Lookalikes New Zealand pygmyweed can be confused with water starworts (Callitriche spp.) which are distinguished by their notched or spanner-shaped leaf tips and inconspicuous flowers. Blinks (Montia fontana) has fatter elliptical or paddleshaped leaves; flowers have 5 petals. It can also be confused with the scarce waterworts (Elatine spp.) and the rare native pygmyweed (Crassula aquatica). Water fern can be confused with duckweeds (Lemna spp.) which are always green with unbranched stems. Elodea spp. and curly water-thyme submerged stems of mare s tail (Hippuris vulgaris) has pale green leaves in whorls of 6-12; usually stems are held above the water. Slender naiad (Najas flexilis) has leaves irregularly arranged in pairs as well as whorls of 3. It also has small flowers and fruits in the angle between the leaves and stem. Floating pennywort is similar to the native marsh pennywort (Hydrocotyle vulgaris). The leaves of marsh pennywort are round and complete, not kidney shaped. It occurs in bogs and fens and does not have floating leaves. Submerged parrot s feather could be confused with spiked water milfoil (Myriophyllum spicatum) or alternate water milfoil (M. alterniflorum), but these plants are never truly emergent. They can also occur in fast flowing water, unlike parrot s feather. Hornwort species (Ceratophyllum spp.) and mare s tail have similar whorled leaf arrangements. Hornworts leaves have tuning fork ends and mare s tail leaves are not divided Set a threshold The site manager should set a threshold of the population size or percentage cover of macrophytes that is acceptable in the individual situation. In the case of most invasive non-native species, a zero threshold will be the aim, although if the population is well-established the cost and likely success of control will need to be balanced against the benefits. When setting a threshold for native species, key aspects to consider are: What is the risk to the freshwater ecosystem where macrophytes could become dominant? The abundance of the macrophytes and their potential for increase. Integrated Pest Management in Nature Conservation 43

44 The ecological benefits of macrophytes to the site Prevention The invasive non-native species covered here are those already present in Scotland or which may pose a threat in the future. All of these plants are generally dispersed as vegetative fragments either via watercourses, machinery or human activity. Water fern spores can also be spread by similar mechanisms. Dispersal can also be the result of deliberate introduction of the plants from domestic garden ponds, garden centres or dumped garden waste. Nature conservation sites should be monitored for presence of these species. The movement of vegetative fragments of aquatic weeds into water bodies via machinery or human activity should be prevented. There is currently a range of initiatives in Scotland to raise awareness of the threat of invasive non-native species and prevent their spread: 1. The Rivers and Fisheries Trusts of Scotland (RAFTS) RAFTS is a conservation charity representing Scotland s national network of Rivers and Fisheries Trusts and Foundations. RAFTs has a Biosecurity and Non Native species Programme and within this has developed local biosecurity plans for the 20 member trusts. These include development and maintenance of local reporting systems for the detection, monitoring and surveillance of INNS. The RAFTS Biosecurity and INNS Programme has its own website ( that provides access to work being undertaken including the potential and actual means of introduction and spread of a range of non-native species, completed biosecurity plans and the legal and planning framework in which those plans are placed. Management and awareness strategies are also included to deal with those invasive nonnative species that threaten the biodiversity and economies of Scotland s rivers and lochs. 2. Be Plant Wise The Be Plant Wise campaign 18 is designed to raise awareness amongst gardeners, pond owners and retailers of the damage caused by invasive aquatic plants and to encourage the public to dispose of them correctly. 3. Check, Clean, Dry The Check, Clean, Dry campaign 19 is aimed at water users to prevent the spread of invasive species between water bodies on equipment, shoes and clothing Integrated Pest Management in Nature Conservation 44

45 2.4.4 Control The control of freshwater macrophytes is very labour intensive due to the ability of the plants to multiply from very small fragments and the difficulty of working in water. The decision tree in Figure 4 will assist with selecting the most appropriate technique. If an invasive non-native species is present, a control programme should normally be considered. Native species will only require control if they become over-abundant and reduce the value of the habitat or alter ecosystem function, for example by outcompeting other valuable species, by impeding flow in a watercourse or by significantly reducing an area of open water. Some mechanical methods such as shading and dyes, and chemical control are non-selective and can have a catastrophic local effect on plants and invertebrates. Their use will therefore be limited to situations where they can be directed at the target species with minimal risk to other organisms Chemical control of aquatic macrophytes Glyphosate is the only herbicide with recommendations for use in or near water. Only some products are allowed for use in or near water. The list may change and up to date label recommendations can be found by checking the Chemicals Regulation Directorate pesticide register database 20, and selecting Aquatic use permitted in the drop down box for Aquatic use. The Scottish Environment Protection Agency (SEPA) must be consulted before applying herbicide in or near water. Adjuvants can be mixed with glyphosate to improve its activity on emergent aquatic plants that are difficult to control. Currently only a few are recommended for use in enclosed waters, intertidal zones of estuary, saltmarsh, land immediately adjacent to aquatic areas or open waters. Current recommendations can be checked in the Chemicals Regulation Directorate pesticide register adjuvants database Integrated Pest Management in Nature Conservation 45

46 Are freshwater macrophytes to be controlled submerged, floating or emergent? SUBMERGED FLOATING EMERGENT Are invasive species present? Are invasive species present? Are invasive species present? YES NO NO YES YES NO Control Cutting programmes Shading Use of coloured dye Control Biological Physical removal Mechanical Control Mechanical Physical removal Shading Review the strategy- has the infestation been controlled? Review the strategy- has the infestation been controlled? NO NO Repeat strategy Repeat strategy Or Consider use of herbicide What risk is posed by plants to the surrounding habitat? What risk is posed by plants to the surrounding habitat? What risk is posed by plants to the surrounding habitat? HIGH LOW HIGH LOW HIGH LOW Control Cutting programmes Shading Use of coloured dye Control Biological Mechanical Physical removal Control Mechanical Physical removal Shading Monitor occurrence of infestation and be ready to control if problem returns. Figure 4: A decision tree to guide the selection of methods to control fresh water macrophytes Integrated Pest Management in Nature Conservation 46

47 Table 9: Freshwater macrophytes possible herbicides for their control. Group Uses Herbicides Application methods Timing 1. submerged No chemical options for control 2. floating Aquatic areas, Enclosed waters, Open waters Glyphosate Foliar spray via boator vehicle-mounted or hand-held equipment. Only emergent and floating weeds onto which the spray is directed are killed. Repeat applications are usually necessary, especially if the mat is thick. 3. emergent Aquatic areas, Enclosed waters, Open waters Glyphosate Foliar spray via boator vehicle-mounted or hand-held equipment. March to October when weed is emerged. Addition of an adjuvant will improve control Group 1: Submerged plants Mechanical control and physical removal Hand-cutting or raking techniques or machinery can be used to clear aquatic plants using purpose-built weed-cutting boats, as well as bank-mounted machines using equipment such as Bradshaw buckets. Whatever method is used, it is important to ensure that cut weed is removed from the water, to minimise risks of deoxygenation associated with the decay of large quantities of cut plant material within the system. Regrowth of plants is usually fairly rapid (days to weeks, depending on conditions and season). Turion (winter bud) removal from sediment in early winter using a weed harvester might be an option for control of Elodea species, as it has been shown to give effective control of whorled water-milfoil (Myriophyllum verticillatum) in the following year and reduced growth in the subsequent growing season (Vernon & Hamilton, 2011). This method could reduce the impact on wildlife. Canadian waterweed: Cut and remove, beginning in March. Repeat every 1-2 months. Cutting in early spring (March) may delay the peak biomass period and repeated cutting will continue to weaken the plant. Nuttall s waterweed: The roots of this species die in June and it reaches maximum biomass in September. After September it becomes prostrate in preparation for overwintering. Cutting will control the plant for short periods depending on its growth phase. Cutting very early in the season from mid-february will limit growth and give 8- Integrated Pest Management in Nature Conservation 47

48 10 weeks control. Cutting at the time of slowest growth (before July) will reduce the level of regrowth and may negate the need for a second cut. New Zealand pygmyweed: Mechanical control should not be attempted as small fragments as small as a single node (5 mm) can spread the infestation or re-infest the treated area. Curly water-thyme: The plant overwinters at depth, so early season removal should also be at depth, or delayed until growth occurs in April. Parrot s feather Regular cutting should take place at least every 6-9 weeks and more frequently if necessary. Cut material and all fragments should be removed from the water as soon as possible. Any smaller fragments of stems should be removed by hand. Nutrient management Modifying water quality may provide a level of control of Elodea species (Vernon & Lilley, 2011). This might be achieved by removing the point source of nutrients such as outputs from sewage works or farm effluent. A method of reducing the level of phosphate in the water is available. Lanthanummodified bentonite clay is a lake remediation tool designed to strip dissolved phosphorus (P) from the water column and increase the sediment P-sorption capacity. This has been used in the Clatto reservoir, Dundee (Meis et al., 2012). Shading Shading using opaque material such as black plastic, thick hessian matting or weed control fabric can reduce growth but will also affect other aquatic plants in the area treated. Shading is therefore only suitable where there are single-species stands present or if other species are able to re-colonise following treatment. New Zealand pygmyweed: The plant is relatively tolerant to shade. Small patches can be covered with black polythene or carpet for 3 months during the growing season; the range can be 8 weeks to 6 months for complete control. In Mochrum Loch, initially 1 ha of habitat infested with New Zealand pygmy weed was covered with weed control fabric in spring A further survey of the Loch in September 2010 showed that the cover of New Zealand pygmy weed had decreased from 516 to 268 square metres. More information can be found on SNH s website 22. Canadian waterweed, Nuttall s waterweed, curly water-thyme: Results to date are inconclusive as to the effectiveness of shading for Elodea species. Planting trees on the south side of a water body can increase shading but will affect other plants and the aquatic ecosystem. Use of a floating sheet 22 Integrated Pest Management in Nature Conservation 48

49 Dyes of opaque material such as black polythene has been tried but with limited success (Vernon & Lilley, 2011). Shading at the benthic level has been trialled successfully in Ireland for control of curly water-thyme but anchorage of the material was a problem. Use of Geojute has resulted in promising results as the material is biodegradable (Vernon & Lilley, 2011). The use of dyes has been recommended for Elodea spp. as a means of in-water shading. Treating water with a non-toxic dye (Aquashade) before the plant begins to grow in spring (water temp <8-10 C) is recommended, with control repeated in 8-10 weeks. Dyes are non-selective and will affect non-target species including phytoplankton, algae and other macrophytes so their application will be limited. They are unlikely to be effective at larger sites. Biological The use of grass carp (Ctenopharyngodon idella) has previously been advocated as a control measure for aquatic plants. However, there are severe legal restrictions on the use of grass carp and their introduction is unlikely to be approved. Introductions require a licence from the Scottish Government, as their release without consent is prohibited under the Wildlife & Countryside Act 1981, as updated by the Prohibition of Keeping or Release of Live Fish (Specified Species) (Scotland) Order Grass carp are not selective and graze any plant species present. They can also upset trophic relationships in the food web and cause problems such as turbidity and eutrophication. They can also escape to other waterways, even through fish barriers. Chemical No options for control are available for submerged plants. However, if submerged plants become exposed due to lowered water levels, they can be treated as for emergent species. Reducing water levels artificially within their natural range might be possible but permission from SEPA would be required. There would be need to consider ecological impacts on shallow zones which would be left dry. Complete drainage would only be feasible in small water bodies such as ponds, and only if the habitat was already severely degraded and of low conservation interest Group 2: Floating plants Free-floating plants and plants with floating leaves and rooted to the substrate can be controlled by mechanical or chemical methods. Control of water fern is best done using chemical means or biological control. Mechanical control and physical removal Free-floating plants are relatively easily removed by mechanical means as long as all fragments are collected. Rooted plants with floating leaves are more difficult to control and need to be cut regularly to deplete the rooted parts. Integrated Pest Management in Nature Conservation 49

50 Water fern This species can be removed by weed buckets or flushing out using baffle boards or barriers to raise the water level temporarily. Removing plants is generally only effective in smaller water bodies and needs to be repeated frequently. Small fragments should be removed by hand. If spores have been released, the area should be checked every 6 months until all the spores have germinated and been controlled. Floating pennywort Regular cutting between May and October will prevent the weed becoming dominant. Maximum growth is during the late summer or early autumn when it forms extensive floating mats. I t overwinters in the margins and on banks as a much flatter, smaller plant. Cutting and careful removal of all fragments by hand is the best option for control. The plant can be cut using a boat-mounted weed cutting bucket. The areas for cutting should be fenced or netted off to reduce the risk of fragments moving downstream. All cut material should be removed from the water and all remaining plants removed by hand. Shading is not a viable option for control. Biological control The North American weevil Stenopelmus rufinasus can be used to successfully control water fern. The weevil is already present in the UK (first recorded in 1921), and because of its long occupancy it is now considered to be ordinarily resident, with no licensing restrictions. Treatment early in the season produces the best results 23. Chemical Water fern Floating mats of water fern can be sprayed with glyphosate (6.0 l/ha). This is best carried out when a gentle wind or currents have collected floating fronds together at suitable points. Repetition of the treatments will be necessary especially if there is a thick mat of vegetation. Recolonisation of the weed can be rapid. Floating pennywort Floating pennywort is best controlled by applying glyphosate up to the middle/end of July with the addition of an adjuvant to improve control. However, to minimise damage to non-target species, chemical treatments can be delayed until the end of the growing season when all other plants have died back. Decomposition of both species takes up to 6 weeks in slow flowing water. However, thick mats can act as a barrier to smaller leaves and control will not be complete. Follow up treatments will be necessary with spot treatment through a hand lance or removal of live plants by hand, 2-4 weeks after the first application Integrated Pest Management in Nature Conservation 50

51 Group 3: Emergent plants Mechanical control and physical removal Mechanical control is not recommended because small fragments can quickly reinfest the area and they can also be dispersed to other areas. Removal by hand is an option for small areas if there is a loose substrate that allows plants to be uprooted easily. Shading Small areas can be covered with black polythene or similar for around 3 months during the growing season; the range can be 8 weeks to 6 months for complete control. Chemical Chemical control is the most effective means of control for both New Zealand pygmyweed and Parrot s feather. Foliar sprays of glyphosate (6.0l/ha) can be applied to emergent stands from March to October; regular treatment is required with up to 2 applications per year necessary. The addition of an adjuvant or codacide oil has improved control of these species, by improving adhesion of the herbicide to the leaves. For small areas, glyphosate in a weed wiper can be used to reduce dominance of the target species, if sensitive vegetation is in close proximity Re-evaluation and monitoring Continue to monitor the area. Macrophytes can re-establish rapidly if propagules are still present and if conditions are favourable, so a rapid response might be needed. In watercourses, the areas downstream of the original infestation should be checked in particular. Re-evaluation should be carried out in the context of informing a control programme for the next year. Points to consider are: Was the management decision correct and did the action taken have the desired results? If a treatment was used, did it work well? What were the advantages and disadvantages? Did the treatment have any beneficial or detrimental effect on the conservation interest of the site? Where the infestation on site constitutes a high risk, chemical methods may need to be considered if a programme of non-chemical control has either not been effective to ensure the desired eradication, or if non-chemical methods are impracticable for the site (for example, labour requirements, access, etc.). Monitoring is key to an effective strategy. Native species with potential for rapid increase should be monitored to ensure they do not present a risk in the future. In the case of invasive non-native species, even if eradication has been achieved, the site and nearby areas should be monitored to ensure the plants do not recolonise. Integrated Pest Management in Nature Conservation 51

52 2.4.6 References and sources of information Meis, S., Spearsa, B.M., Maberly, S.C., O Malley, M.B. & Perkins, R.G. (2012) Sediment amendment with Phoslock in Clatto Reservoir (Dundee, UK): Investigating changes in sediment elemental composition and phosphorus fractionation. Journal of Environmental Management 93, Scottish Government (2012) The Code of Practice on Non Native Species The UK Pesticide Guide (annually updated) The Voluntary Initiative Environment Information Sheets on pesticides: Canadian pondweed Newman, J.R. and Duenas, M.A. (2010) Information Sheet 7: Elodea canadensis (Canadian Waterweed) GB Non-Native Species Secretariat Vernon E & Hamilton H (2011) Literature review on methods of control and eradication of Canadian pondweed and Nuttall s pondweed in standing waters. Scottish Natural Heritage commissioned report No Nuttall s waterweed Newman, J.R. & Duenas, M.A. (2010) Information Sheet 25: Elodea nuttallii, Nuttall s pondweed GB Non-Native Species Secretariat Water fern CEH (2004) Information Sheet 22: Azolla filiculoides Water fern Non-Native Species Secretariat New Zealand pigmy weed GB Non-Native Species Secretariat Willby, N. (2008). Risk assessment of the threat posed by existing populations of New Zealand Pygmyweed Crassula helmsii in Scotland. Scottish Natural Heritage commissioned Report No Integrated Pest Management in Nature Conservation 52

53 Scottish Natural Heritage Species Action List INNS Floating pennywort GB Non-Native Species Secretariat Plant Protection Service, Wageningen, NL and Centre for Ecology and Hydrology Wallingford, UK (2011) Hydrocotyle ranunculoides L. f. A guide to Identification, Risk Assessment and Management. Parrot s feather GB Non-Native Species Secretariat Plant Protection Service, Wageningen, NL and Centre for Ecology and Hydrology Wallingford, UK (2011) Myriophyllum aquaticum (Vell.) Verdcourt. A guide to Identification, Risk Assessment and Management. Integrated Pest Management in Nature Conservation 53

54 Part 3 Protocols for the management of other Species Integrated Pest Management in Nature Conservation 54

55 3.1 IPM protocol for the control of Creeping Thistle (Cirsium arvense) Background Gavin Johnson/SNH Creeping thistle (Cirsium arvense) is a native perennial species of the British Isles. The flowers provide a pollen and nectar source for insects including bumblebees. The seeds are an important food source for granivorous birds. It is covered under the Weeds Act It is the most common perennial weed of grassland but is also widely distributed in disturbed, moderately fertile habitats and tall herb communities. Root fragments remain dormant for many years until disturbed and fragments from encroaching field margins are often spread into the field via cultivations It can rapidly become the dominant plant if it is not managed. It favours nutrient-rich, loam soils Identifying the problem Lifecycle Creeping thistle is a perennial, dicotyledonous plant that flowers from July to September. It spreads mainly vegetatively, via underground creeping roots, but some seed spread does occur. Seed spread: Creeping thistle plants are almost always dioecious (i.e. male and female parts on separate plants). Seeds can be shed from August onwards but some remain in the seed head until winter. The majority of seeds will germinate in the following season, with some surviving up to five years in the soil seedbank. Seedlings require soil disturbance and low competition from other plant species for survival. After six months, a seedling can have developed a tap and lateral roots and penetrate over 2 feet deep. Integrated Pest Management in Nature Conservation 55

56 Vegetative spread: The underground rooting system of creeping thistle is divided into three parts: thin shallow roots, thickened roots and subterranean shoots. The deep creeping roots are very brittle and easily break into small fragments with the ability to regenerate into individual plants by producing aerial shoots and new roots. After flowering has ended in late summer the plant dies back to just below the soil level in the autumn and winter and stays dormant until new shoots grow the following spring. Root fragments can remain dormant in the soil for a number of years Identify Creeping thistle is most easily identified at the flowering stage, however dark green rosettes are present from spring onwards. Table 10: Main features of creeping thistle Plant An erect plant up to 150cm high, often in clumps Stems Leaves Flowers Seeds Stems are unwinged and shiny green/brown. Leaves are hairy above, with a prickly leaf margin. A basal rosette of leaves usually dies before flowering but stem leaves persist. Flowers are conspicuous, numerous purple/reddish flower heads, with tubular ray florets and smaller disc florets during June to September. Flower head is 15-20mm in size. Female flowers produce white feathery pappus and are scented, male flowers unscented and the pappus turns brown. Small brown/olive green ovate seeds, approximately 4mm in length. Individual seeds bear 40+ feathery hairs that create a parachute effect, spreading open in the air dispersing the seed. Each flowering head can produce seeds Lookalikes There are several thistle species that are superficially similar, the most common being spear thistle (Cirsium vulgare), marsh thistle (C. palustre) and welted thistle (Carduus crispus). However, all these three species have spiny-winged stems. Creeping thistle can be mistaken for spear thistle particularly when young. At an early growth stage spear thistles have a large and densely hairy second leaf. Integrated Pest Management in Nature Conservation 56

57 Set a threshold Creeping thistle can spread quickly forming dense patches and is highly competitive to surrounding vegetation when poorly managed. Control of creeping thistle would be appropriate if it is invading grassland of high nature conservation value, to the detriment of the existing botanical diversity. In that situation, eradication from sensitive parts of a site might be justified. Very occasionally control might also be needed to prevent spread to neighbouring land, though if the population is that large, it is likely to be causing problems on the site itself. If the nature conservation value of the site is dependent on agricultural management, high cover of thistles might be detrimental if it compromises agricultural productivity to such a degree that it discourages the occupier from carrying out this management. The site manager should set a threshold of the population size or percentage cover of creeping thistle that is acceptable in the individual situation. When setting a threshold, key aspects to consider are: What is the risk to surrounding vegetation where creeping thistle could become dominant? The size of the population. The ecological benefits of the plant to the site. Targets for favourable condition on sites designated as SSSIs or Natura sites, normally require no more than 5% cover of creeping thistle on grasslands or 1% on heaths and bogs Prevention In grassland areas, under-utilisation (grazing) of pasture when thistles are present in combination with overgrazing in the winter and early spring results in an open sward that is late to develop. The thistles can then out-compete the grass species and dominate the vegetation. Cutting shoots at a young stage or close stocking may reduce the infestation. A key factor of any control strategy in grassland is to avoid bare ground. Avoid the problem by maintaining good ground cover. If stock is present, manage stocking levels to avoid under or over grazing and avoid poaching. In field margins and other marginal areas, competition from a dense sward of grasses and other species will suppress creeping thistle. Spot treating individuals can help to prevent spread Control The options for control consist of both non-chemical and chemical methods and no single method provides complete control in one season. An integrated control programme could require 5 to 10 years of persistent operations to completely eradicate this species. Control might need to be repeated over several seasons to reduce or maintain populations below the acceptable threshold level. Control can often be erratic as external factors such as weather and soil conditions have an impact on the levels of control achieved. For example, cutting is more effective in Integrated Pest Management in Nature Conservation 57

58 dry conditions as regrowth is compromised but pulling is improved in wetter conditions as the thistles are easier to remove. Chemical control should only be used where non-chemical methods have failed to achieve the desired level of control. The decision tree in Figure 5 will assist with selecting the most appropriate technique Non-chemical methods Non-chemical control can be labour intensive but if applied correctly can provide successful control over a period of time. Where stock are present, the grazing removal period is much shorter than with chemical control. Non-chemical methods are generally more suited to lower populations in smaller areas. Grazing Cattle grazing reduces thistle numbers compared to sheep. Horses and sheep will eat young fresh thistle shoots, but the older mature stems are not palatable. Sheep grazing reduces competition from the surrounding competition, encouraging young shoots to develop and spread and new seedlings to establish. Goats, donkeys and llamas will eat creeping thistle, particularly the flowers. Cutting or Mowing Repeated cutting and mowing can reduce creeping thistle populations, but this requires a number of years to take effect. Mowing after grazing to a height of 5 cm over a period of 4 years has a significant impact on the creeping thistle population, to almost total elimination. Cutting should be carried out at least twice a year in the main growing season and should cut plants low enough to remove all leaves. If cutting/mowing just before flowering, the plant should have its lowest reserves in the root stock and this may aid control. Repeated cutting/mowing also prevents seed production. Burners Spot burners (hand held flame guns) can be used at the rosette stage and provide some control. However, there could be a potential for damage to surrounding vegetation and a risk of fire. This method is unlikely to be suitable except on hard surface or paved areas. Biological control No measures are currently available in the UK. Integrated Pest Management in Nature Conservation 58

59 What is the level of risk posed by creeping thistle? High- creeping thistle at high populations which are detrimental to the conservation value of the site. Does the site have topographical or other constraints which prevent the use of a vehicle? Medium- creeping thistle present in large numbers on site, but not at the detriment of other valuable species. Monitor closely and be ready to control if risk increases. Consider maintaining populations at existing levels. Low - few plants on site. No imminent action required, creeping thistle is probably of conservation value. NO YES Mowing followed by grazing. Review the strategy- has the infestation been controlled? Hand cutting followed by grazing. Consider the use of herbicide. NO Consider use of herbicide. Monitor occurrence of infestation and be ready to control if problem returns. Figure 5: A decision tree to guide the selection of methods to control Creeping Thistle Chemical Control Choice of herbicide Of the selective herbicides aminopyralid, clopyralid, fluroxypyr, triclopyr are more effective at killing creeping thistle and will give more persistent control than 2,4-D, dicamba, MCPA. Integrated Pest Management in Nature Conservation 59

60 Glyphosate will kill the plant and others around it. Selectivity can be increased by applying glyphosate with a weed wiper or via a hand-held lance. Fitting a guard to the lance will minimise the area affected by the spray. Spraying with vehicle mounted equipment should be considered only where there are no species of conservation value which will be affected by the herbicide. Always read the product label prior to using an herbicide. Table 11: Creeping thistle (Cirsium arvense) - possible herbicides for its control. Herbicides Uses Application methods Timing 2,4-D Amenity grassland, Grassland, Managed amenity turf Foliar spray via vehicle mounted or hand-held equipment Apply from cotyledon to early flower bud stage. Only aerial growth is controlled and repeat applications will be necessary in future years. 2,4-D + dicamba Managed amenity turf Foliar spray via vehicle mounted or hand-held equipment Apply when the seedlings/young plants are up to 50cm high. Only aerial growth is controlled and repeat applications will be necessary in future years. 2,4-D + dicamba + triclopyr Grassland, Forest, Amenity grassland, Land not intended to bear vegetation, Foliar spray via vehicle mounted or hand-held equipment. Weed wiper or rope wick applicator Apply when actively growing between the rosette stage to before the flower buds open. 2,4-D + MCPA Grassland Foliar spray via vehicle mounted equipment. Some products can be applied using hand-held equipment. Good control if timed correctly. Treat at the early flowering stage. Dicamba + mecoprop-p Permanent grassland, Rotational grassland, Amenity grassland, Managed amenity turf Foliar spray via vehicle mounted or hand-held equipment Apply at early flowering, shoots will be killed but repeat treatments will be necessary Aminopyralid + fluroxypyr Amenity grassland, Grassland Foliar spray via vehicle mounted or hand-held equipment (Synero only) Actively growing in the rosette stage up to 25cm high Aminopyralid + triclopyr Amenity grassland, Grassland Foliar spray via vehicle mounted. Do not apply by handheld equipment. Treat when actively growing in rosette stage or up to 25 cm high. Integrated Pest Management in Nature Conservation 60

61 Herbicides Uses Application methods Timing Clopyralid Grassland Foliar spray via vehicle mounted or hand-held equipment. Do not apply before 1 st March in year of harvest. Apply to young, actively growing seedlings. Treat at rosette stage, when cm across. Repeat 3-4 weeks later. Clopyralid + fluroxypyr + triclopyr Grassland Foliar spray via Vehicle mounted or hand-held equipment. At the rosette stage up to 25cm tall or wide. Clopyralid + triclopyr Amenity grassland, Grassland Foliar spray via vehicle mounted or hand-held equipment. Tractor mounted weed wiper (SOLA). Do not apply using hand-held rotary atomiser equipment. Spray when actively growing from the rosette stage up to 20cm tall or wide but before flowering. Increase rate for larger plants. Glyphosate Unwanted vegetation, Grassland, Forest, Surfaces not intended to bear vegetation, Amenity vegetation, Land immediately adjacent to aquatic areas Foliar spray via vehicle mounted or hand-held equipment. Weed wiper. Rotary atomiser. The optimum time for treatment is from buds are visible to before seed set or senescence, late June to early September. Spraying during flowering will prevent seed set. Topping in April/May can even up thistles for weed wiping in August. 95% control can be achieved in 1 year. MCPA Grassland Foliar spray via vehicle mounted equipment. Some products can be applied using hand-held equipment. Triclopyr Unwanted vegetation Foliar spray via vehicle mounted or hand-held equipment. Do not apply by hand held applicator rotary atomiser. Do not apply before the end of February in the year of harvest. Thistles are only moderately susceptible and should be actively growing. Optimum timing when the purple buds are visible. Aerial parts will be killed but repeat treatments will be necessary. During the summer from rosette stage up to flower buds visible. Integrated Pest Management in Nature Conservation 61

62 Effect on non-target species Glyphosate is a non-selective herbicide that kills most plants including grasses. Aminopyralid, clopyralid, fluroxypyr, triclopyr, 2,4-D, dicamba, MCPA are selective herbicides and control a wide range of broad-leaved plants. They have little or no effect on grasses. The mixture of 2,4-D, dicamba and triclopyr can cause a temporary suppression of bents (Agrostis spp.) and Yorkshire fog (Holcus lanatus). Clopyralid kills members of the Asteraceae and Fabaceae families. When applying triclopyr to areas with trees, protect them with a tree guard and direct spray away from leader shoots Re-evaluation and monitoring Continue to monitor the area for regeneration of thistle shoots from underground rootstock. It is also worth checking for new populations establishing in other areas of the site. Re-evaluation should be carried out in the context of informing a control programme for the next year. Points to consider are: Was the management decision correct and did the action taken have the desired results? If a treatment was used, did it work well? What were the advantages and disadvantages? Did the treatment have any beneficial or detrimental effect on the conservation interest of the site? Where the infestation on site constitutes a high risk, chemical methods may need to be considered if a programme of non-chemical control has either not been effective to ensure the desired eradication, or if non-chemical methods are impracticable for the site (for example, labour requirements, access etc). Monitoring is key to an effective strategy. In particular, where plants represent a low risk and control was not necessary, the infestation should be monitored to ensure it does not present a higher risk in the future References and sources of information Bond W & Turner RJ, (2004). The biology and non-chemical control of Creeping Thistle (Cirsium arvense). Centre for Ecology and Hydrology (2006) Sustainable management strategies for creeping thistle. SRUC (2012) Weed management in grassland. Technical Note TN643 assland SAC (2010) Management of species rich grasslands. Technical note TN629 rich_grasslands Integrated Pest Management in Nature Conservation 62

63 The UK Pesticide Guide (annually updated) The Voluntary Initiative Environment Information Sheets on pesticides: Integrated Pest Management in Nature Conservation 63

64 3.2 IPM protocol for the control of ragwort (Senecio jacobaea) Background Lorne Gill/SNH Common ragwort (Senecio jacobaea) is a native species of the British Isles. It is covered under the Weeds Act Responsibility for control lies with the occupier of the land. It is a natural component of grassland on freely-draining soils and of rocky habitats. Common ragwort supports a large number of specialist invertebrate species compared to other plants. At least 30 species of insect and other invertebrates are totally dependent on ragwort as their food source and many other species feed on the plant or use it as a nectar or pollen source. More details on the insect species supported can be found on the Buglife website 24. It contains toxins that can have debilitating or fatal consequences if eaten by horses or other grazing animals. The plant is not toxic to humans as the alkaloids present in the plant are poorly absorbed through the skin. Dried plants are more likely to be eaten by stock Identifying the problem Lifecycle Ragwort is a biennial or short-term perennial. In the first year of growth, it takes the form of a rosette of leaves flat to the ground. It flowers in the second year and after flowering the plant then dies. Ragwort can be a short-term perennial if the flowering stem is repeatedly removed by cutting or grazing before seeds are set Integrated Pest Management in Nature Conservation 64

65 Identify Common ragwort is most easily seen and identified at the flowering stage by its yellow daisy-like flowers. It is less obvious at the rosette stage, but can be identified by its deep bottle green leaves, tinged with purple and slightly glossy on the upper surface of the leaf. Table 12: Main features of Ragwort Plant Stem Leaves Flowers Seeds An erect plant 30-90cm high but may exceed 100cm. Stems are tough and often tinged red near the base but brighter green and branched towards the middle. A basal rosette of leaves usually dies before flowering but stem leaves persist. Leaves are deeply dissected with irregular jagged lobes. Leaves are dark green, tinged purple, tough and maybe sparsely hairy on the lower surface. Flowers are conspicuous, large flat topped head of densely packed yellow flowers with ray florets and disc florets all of which are bright yellow Seeds are borne singly and have a downy appendage that makes them readily dispersible Lookalikes Common ragwort is similar in appearance to a range of other ragwort species Marsh ragwort (S. aquaticus), S. aquaticus x S. jacobaea and Oxford ragwort (S. squalidus) are the species which occur most commonly in Scotland. Marsh ragwort is an important component of wet mesotrophic grasslands and would not normally need to be controlled. Correct identification of ragwort species is therefore vital. Other ragwort species with restricted distribution in Scotland include Hoary ragwort (S. erucifolius) and a number of alien species originating as garden escapes. All ragwort species are toxic to stock but only S. jacobaea is covered by the 1959 Weeds Act. Integrated Pest Management in Nature Conservation 65

66 Set a threshold There are two scenarios for setting a threshold. 1. Presence on sites of high nature conservation value. Ragwort can be highly competitive and certain situations could be a high risk for ragwort establishment. Species-rich grasslands could be at risk where rabbit damage or trampling in public areas exposes bare ground to colonisation. Sites with bare ground important for invertebrates and annual plants (open mosaic habitat, e.g. on brownfield sites) can be colonised by ragwort, which can reduce the area of open habitat required by these groups. If the nature conservation value of the site is dependent on agricultural management, high cover of ragwort might be detrimental if it compromises agricultural productivity to such a degree that it discourages the occupier from carrying out this management. If the site is over 100m from land used for grazing by livestock, the site manager should set a threshold of the population size or percentage cover of ragwort that is acceptable in the individual situation. When setting a threshold, key aspects to consider are: What is the risk to surrounding vegetation where ragwort could become dominant in the sward? The level of infestation. The ecological benefits of the plant to the site. The proximity of the site to grazing livestock and other animals. Targets for favourable condition on sites designated as SSSIs or Natura sites, normally require no more than 5% cover of ragwort on grasslands or 1% on heaths. 2. Harbouring a source of seed for dispersal to nearby land Ragwort poses a risk when it threatens to invade land used for grazing or forage production. The following risk assessment from the Defra Code of Practice (Table 13) determines whether action should be taken to prevent the spread of ragwort. The risk assessment should also consider the direction of the prevailing wind and the natural topography of the area which could, for example, increase the risk of wind-borne seed dispersing from an exposed site into more sheltered areas. The presence or absence of shelter belts or natural barriers and the soil type and vegetation type of the land at risk are also important to consider. Ragwort is less likely to infest a well-managed grassland with a closed sward. Integrated Pest Management in Nature Conservation 66

67 Table 13: Risk assessment of threat posed by ragwort. Level of risk Details Action High Medium Low Present and flowering/seeding within 50m of land used for grazing by horses and other animals or land used for forage/feed production. Infestation in species-rich grassland where there is an observed or serious risk from competition. Present and within 50m-100m of land used for grazing by horses and other animals or land used for forage/feed production. Ragwort is present on land more than 100m from land used for grazing by horses and other animals or land used for forage/feed production. Take action to control the spread of ragwort. Continue to monitor and establish a control policy to prevent a change from medium to high risk. No immediate action required Prevention In grassland, common ragwort can establish where trampling of livestock or humans breaks the sward, where patches of turf have died due to poor nutrition, pest or disease, or where there is over or under grazing by stock or rabbits. Any disturbance which leads to open soil is favourable to seedling establishment. The key factor of any control strategy in grassland is to avoid bare ground. Avoid the problem by maintaining good ground cover. If stock is present manage stocking levels to avoid over grazing and poaching. Ragwort might also colonise under-grazed sites if lodging results in vegetation dieback and creation of bare patches. Control of rabbits may be necessary to maintain good ground cover. Prevent excessive trampling by the public and consider using marked walkways with hard surface paths. In open mosaic habitat, ragwort is most likely to colonise where the soil surface is disturbed and nutrient levels are higher. Identify any source of disturbance and control public access and rabbit populations where necessary. Monitor surrounding vegetation for the presence of ragwort; populations within m could provide a seed source for infestation. Increase the level of monitoring in these situations Control The options for control consist of both non-chemical and chemical methods. Control might need to be repeated over several seasons to reduce or maintain populations below the acceptable threshold level. Chemical control should only be used where non-chemical methods have failed to achieve the desired level of control. The decision tree in Figure 6 will assist with selecting the most appropriate technique Non-chemical Non-chemical control can be used to reduce ragwort populations but will need to be Integrated Pest Management in Nature Conservation 67

68 repeated regularly to prevent its re-establishment. Where livestock are present the grazing removal period is much shorter than with chemical control. Non-chemical methods are generally more suited to lower populations in smaller areas. All animals are susceptible to the toxic effects of ragwort and therefore deliberate control of ragwort by grazing should not be undertaken on animal welfare grounds. Cutting Cutting does not control ragwort but reduces seed production and dispersal where other control methods cannot be used. Depending on the time of cutting, it can stimulate regrowth and the plant can flower later in the season. Cutting at early flowering reduces seed production but flowering on the same plant then occurs later in the season. Cut plants are a serious risk to livestock and fatal to horses and cattle as they remain toxic but become more palatable to stock. Seed set may still occur. If stock are present, plants must be removed and safely disposed of. More details on disposal can be found in: Guidance on the Disposal Options for Common Ragwort PB Pulling and levering Removing plants by pulling or levering can prevent seed spread and results in longterm control as long as all root fragments are removed to reduce the risk of recolonisation of the disturbed patch. This is best done when the soil is damp and before the ragwort has seeded. Pulling by machine needs a height difference of approximately 10 cm between the ragwort and the non-target plants and is only suitable on lighter soils and flat sites. All plants must be removed from the site and disposed of, as plants may still set seed and all parts of the plant are toxic. More details on disposal can be found in: Guidance on the Disposal Options for Common Ragwort. Burners Spot burners (hand held flame guns) can be used at the rosette stage. Control is variable with up to 93% of seedlings reported to be killed in some operations but rapid regrowth occurring in others. There could be a potential for damage to surrounding vegetation and a risk of fire. This method is unlikely to be suitable except on hard surface or paved areas Integrated Pest Management in Nature Conservation 68

69 What is the risk posed by ragwort on site? Is ragwort flowering/seeding within 100m of land used for grazing by horses and other animals or land used for forage/feed production? NO Is ragwort compromising the nature conservation value of the site? YES Size of infestation YES NO Low, some plants High, many plants Hand pulling individual plants Weed burner Machine pulling Machine cutting Biological control Review strategy: was the infestation controlled? YES NO Low, a few plants Repeat with non-chemical methods or use a herbicide. Size of infestation? High, many plants Monitor infestation to ensure spread of ragwort does not increase beyond the threshold level. Hand-held - weed wiper, selective spraying or spot treatment Consider spraying with vehicle mounted equipment only where there are no species of conservation interest in the immediate area. Review the strategy, was the infestation controlled? YES Figure 6: A decision tree to guide the selection of methods to control ragwort Integrated Pest Management in Nature Conservation 69

70 Biological control Use of high numbers of cinnabar moth (Tyria jacobaea) can destroy ragwort populations. These are introduced as pupae in biodegradable capsules. Information on where to purchase cinnabar breeding capsules can be found online. This method is not suitable for the control of ragwort on grazing land or land used for forage production because the stem of the plant will still be present and could be eaten by livestock. It is an option for areas where other control methods are unachievable or undesirable. It may be difficult to maintain predator populations and may result in a reduction in the overall ragwort population rather than preventing its dispersal. Approval may be required from Scottish Natural Heritage (SNH) before this technique is used within SSSIs and Natura 2000 sites, and advice should be sought. Biopesticide Citronella oil, a biopesticide, can be applied to control low or local populations of ragwort on land temporarily removed from production or permanent grassland. The product is sold in a 5 l container with and application gun attached. Aerial growth of the plant is rapidly burnt off and plants should be checked after 28 days for regrowth. The optimum timing is at the seedling/rosette stage but all sizes of plant are killed if thoroughly wetted with the herbicide. Citronella oil can also kill grasses, buttercups, broad-leaf dock, and nettles after 1 day but these grow back strongly (Clay et al., 2005) making it safer to use than glyphosate Chemical control Choice of herbicide Application of herbicides can give rapid control of ragwort. There is a range of herbicides that can be used to control ragwort and these are detailed in Table 14. Products containing 2,4-D and/or MCPA can give good control of ragwort but need to be applied at the rosette stage and again before flowering in the second year. These chemicals do not affect grasses. Products containing aminopyralid give better control but may have a greater effect on non-target species. Glyphosate will kill the plant and others around it. Use of a weed wiper or spot treatment with a hand lance can increase the selectivity of this herbicide. Fitting the hand lance with a guard can direct the spray to the target more accurately. Glyphosate is suitable for use near water but permission from SEPA must be sought before treatment. Always check the product label. Ragwort still remains toxic to livestock when dead and it is only safe to graze when the treated plants have disintegrated and are not accessible to grazing animals. The same principles apply to grassland managed for silage, hay and haylage. Spraying with vehicle mounted equipment should be considered only where there are no species of conservation value which will be affected by the herbicide. Integrated Pest Management in Nature Conservation 70

71 Always read the product label prior to using a herbicide. Table 14: Common ragwort (Senecio jacobaea) - possible herbicides for its control Herbicides Uses Application methods Timing 2,4-D Amenity grassland, Grassland, Managed amenity turf Foliar spray via vehicle mounted or hand-held equipment. Apply from cotyledon to before flower buds are formed. Ragwort is moderately susceptible. Only aerial growth is controlled and repeat applications will be necessary in future years. Control is improved by mixing with MCPA. 2,4-D + dicamba + triclopyr Grassland, Forest, Land not intended to bear vegetation, Amenity grassland Foliar spray via vehicle mounted or hand-held equipment. Weed wiper or rope wick applicator. Apply when actively growing between the rosette stage to before the flower buds open. Moderately susceptible, top growth killed. Treat over 2 years for complete control. 2,4-D +dicamba Managed amenity turf Foliar spray via vehicle mounted or hand-held equipment 2,4-D +MCPA Grassland Foliar spray via vehicle mounted equipment. Some products can be applied using hand-held equipment. Spray when the majority of plants are in the rosette stage and growing vigorously in the autumn or spring but before the flower spines start to grow. Treat over 2 years for complete control. Good control if timed correctly. Treat in the autumn followed by a sequential application in the spring at rosette stage, before flower spikes start to grow. Aminopyralid + fluroxypyr Amenity grassland, Grassland Foliar spray via vehicle mounted or hand-held equipment (Synero only) Actively growing in the rosette stage up to 20cm high. Aminopyralid + triclopyr Amenity grassland, Grassland Foliar spray via vehicle mounted equipment. Do not apply by hand-held equipment. Treat when actively growing in rosette stage or up to 20 cm high Integrated Pest Management in Nature Conservation 71

72 Herbicides Uses Application methods Timing Citronella oil Amenity grassland, Grassland Spot spray Rosette stage Glyphosate Unwanted vegetation, Grassland, Forest, Surfaces not intended to bear vegetation, Amenity vegetation, Land immediately adjacent to aquatic areas Foliar spray via vehicle mounted or hand-held equipment. Weed wiper or rope wick applicator. Rotary atomiser From the rosette stage to at or near flowering, but before onset of senescence. Avoid treating when the stem is extending. Treated plants can be removed 5 days after treatment allowing grazing to recommence. MCPA Grassland Foliar spray via vehicle mounted equipment. Some products can be applied using handheld equipment Triclopyr Unwanted vegetation Foliar spray via vehicle mounted or hand-held equipment. Do not apply by hand held applicator with rotary atomiser. Do not apply before the end of February in the year of harvest. Spray in spring when at rosette stage before flower spike starts to extend. Summer (leaves fully expanded, not senescent). Not when very hot or during drought. Effect on non-target species Glyphosate is a non-selective herbicide that kills most plants including grasses. Aminopyralid, fluroxypyr, triclopyr, 2,4-D, dicamba, MCPA are selective herbicides and control a wide range of broad-leaved plants but have little or no effect on grasses. When applying triclopyr to areas with trees, protect them with a tree guard and direct spray away from leader shoots Re-evaluation and monitoring Ragwort is likely to regenerate from seed on areas of bare ground, especially where plants have been pulled, causing local disturbance. If plants have been cut, check for regrowth and any subsequent flowering. Continue to monitor the area. Re-evaluation should be carried out in the context of informing a control programme for the next year. Points to consider are: Was the management decision correct and did the action taken have the desired results? If a treatment was used, did it work well? What were the advantages and disadvantages? Integrated Pest Management in Nature Conservation 72

73 Did the treatment have any beneficial or detrimental effect on the conservation interest of the site? Where the infestation on site constitutes a high risk, chemical methods may need to be considered if a programme of non-chemical control has either not been effective to ensure the desired eradication, or if non-chemical methods are impracticable for the site (for example, labour requirements, access etc). Monitoring is key to an effective strategy. In particular, where plants represent a low risk and control is not necessary, the infestation should be monitored to ensure it does not present a higher risk in the future References and sources of information Bond, W., Davies, G. & Turner, R. (2007) The Biology and Non-Chemical Control of Common Ragwort (Senecio jacobaea L.) Buglife (2011) Ragwort Factfile Clay, D.V., Dixon, F.L. & Willoughby, I. (2005). Natural products as herbicides for tree establishment. Forestry 78 (1), 1-9. Defra (2011) Code of practice on how to prevent the spread of ragwort SAC (2005) Ragwort poisoning in livestock: prevention and control. Technical note TN570. Scottish Government (2008) The Scottish government guidance on how to prevent the spread of ragwort. The UK Pesticide Guide (annually updated) The Voluntary Initiative Environment Information Sheets on pesticides: Integrated Pest Management in Nature Conservation 73

74 3.3 IPM protocol for the control of bracken (Pteridium aquilinum) Background Lorne Gill/SNH Bracken (Pteridium aquilinum) is a native plant with many conservation benefits and is a natural component of many woodlands and open ground habitats. Stands of bracken can provide a valuable habitat, especially when the bracken canopy is relatively open. Bracken provides structure and shelter, supporting over 40 species of herbivorous invertebrates 26, including about 11 species which are found only on bracken, and an additional 14 which feed only on bracken and other ferns. Where patchy, it can provide an important habitat for scarce and declining species of fritillary butterflies as well as birds such as whinchat and nightjar. Woodland ground flora, including regenerating tree seedlings, can survive under bracken stands, provided they are not too dense. Bracken can provide protection from grazing animals as well as acting as a substitute for the woodland canopy. Originally a woodland species, bracken is widespread throughout the UK and a very successful coloniser now common to many upland areas. When bracken stands encroach on other habitats, often as a result of past poor management such as heavy grazing, it might require control to manage its extent. If ingested, bracken can cause poisoning to grazing animals as well as provide a habitat for sheep tick (Ixodes ricinus) which can carry Lyme disease. Bracken features a widespread rhizome system which is buried 10-45cm deep. Bracken can outcompete valuable habitats such as grass and heathland if left unchecked as well as disturbing or destroying below ground sites of archaeological interest. Natural regeneration of trees is generally inhibited under dense bracken (more than 20 fronds per m 2 ). 26 Lawton, J.H. (1976). The structure of the arthropod community on bracken. Botanical Journal of the Linnean Society 73, Integrated Pest Management in Nature Conservation 74

75 3.3.2 Identifying the problem When to control bracken The need for bracken control needs to be carefully considered in the context of the conservation objectives for the site. Bracken can provide a valuable habitat but can also be invasive into open habitats such as heathland and grassland. Generally, the aim of a control strategy will be to manage the extent and density of bracken stands rather than to completely eradicate it. Bracken contains a number of toxins which are harmful to cattle, sheep and horses and care should be taken when grazing sites with bracken. If significant quantities of bracken are ingested by these animals then the effects are usually fatal. However, if plentiful supplies of other forage are available, animals will not usually eat bracken. To this end, it is necessary to ensure that areas are not overgrazed, plentiful forage is available before grazing in the spring and if necessary supplementary feed is provided Table 15: Guidance on situations in which bracken should be controlled or otherwise. Where to control bracken Where bracken has invaded an area of heather or unimproved grassland of conservation interest, and is likely to suppress or eliminate the interest. Where there is a dense and vigorous patch of bracken that clearly threatens to invade an adjacent area of heather or unimproved grassland of conservation interest. Where woodland regeneration or expansion is desired and dense bracken impedes natural regeneration of trees (more than 20 bracken fronds per m2) Where bracken increases the risk of crown fires in woodland. Where not to control bracken Avoid control where sites may play host to other susceptible species. In particular steep valleys with high humidity and rocky areas may contain valuable species such as royal and lemonscented ferns. Where damage from pesticides may affect nontarget species, including young trees, and nonchemical control is not possible. Where there is limited benefit from control and bracken provides a substitute woodland community for plants and insects. On steep sites where there is little opportunity for vegetation recovery, controlling bracken may lead to severe erosion. Where dense stands on routes open to the public may cause a risk of ticks to both humans and other animals (i.e. pet dogs). Where bracken control will provide additional grazing for livestock, helping to reduce overgrazing on heather and unimproved grassland elsewhere. Integrated Pest Management in Nature Conservation 75

76 Lifecycle Whilst individual bracken rhizomes have a limited lifespan of two years, the system is highly persistent with thick storage organs running deep underground Identify Identification of bracken is relatively easy. It is most obvious in dense stands and once fronds are fully emerged. Isolated plants might be less easily identified after dieback in the autumn but these are unlikely to require control. It is distinct from other large ferns in having long-stemmed fronds arising singly from the underground rhizomes and the spore producing bodies being continuous along the leaf margins (instead of round structures on the underside). Table 16: Main features of Bracken Fronds (mature) Fronds (newly emerged) Litter Rhizomes Mature fronds are feather leaved with highly divided individual fronds. Mature fronds are large, typically cm. Young bracken fronds emerge curled up, typically green with a tinge of red towards the end of the frond. Characteristic cinnamon colour once it has died down; deep, persistent litter layer. Bracken features a widespread rhizome system which is buried 10-45cm deep. In mature bracken communities, roots are concentrated nearer the soil surface with rapid reductions at greater depth Set a threshold If bracken is present at such a level on land where its rapid succession would outcompete more valuable habitats, preventative measures should be considered. Due to the persistence and spread of bracken where it occurs in conservation areas, monitoring is essential to prevent its spreading above an acceptable threshold level. The following risk assessment (Table 17) provides a guide to determine what action should be taken to control or prevent the spread of bracken. Integrated Pest Management in Nature Conservation 76

77 Table 17: Risk assessment of threat posed by bracken. Level of risk Details Action High Medium Low Where bracken is the dominant species and has encroached on protected areas/valuable habitats with little diversity in underlying vegetation. Patches of bracken in protected areas/valuable habitats where further spread would come at their expense. Patches of bracken on areas susceptible to erosion or of little conservation value. Take action to control the spread of bracken and control existing populations. Continue to monitor and establish a policy to prevent a change from medium to high risk. Consider control in boundary areas to ensure bracken does not spread further. No immediate control actions required but continue to monitor bracken for spread to other areas. For designated sites, a range of maximum cover values of bracken are recommended to maintain a site in favourable condition. These vary from 1% in bogs, to 10% in upland grasslands and most heathlands, and 25% in most rocky habitats. In lowland grasslands, a maximum of 5% in combination with scrub is recommended (but 50-90% cover of species-rich bracken and scrub can be acceptable in lowland dry acid grassland; JNCC, ) Prevention Bracken can mostly be found in areas of woodland, unmanaged scrub, heathland and hill pasture. It is often indicative of areas that have previously been overgrazed or cultivated, or where woodland has been cleared or retreated as a result of overgrazing. Encouraging woodland regeneration to increase competition on sites where bracken is present can prevent its spread. However, establishment of tree seedlings might be inhibited by a dense bracken canopy or if herbivores such as rabbits or deer are present. Herbivores can be excluded by fencing but dense bracken stands might need to be controlled beforehand and litter removed. Monitoring bracken is particularly important where the site is susceptible to encroachment. Muirburn should not be carried out in areas of heathland where bracken is present as this can increase the competitive advantage of bracken (unless bracken control is also carried out) Control Bracken is difficult to eradicate, and this is usually undesirable anyway, as it is a native species and only problematic when sufficiently dense and excluding other plant species. Eradication will occasionally be desirable where it provides no conservation benefit and rapid re-invasion is likely, as on deep, well-drained soils. Usually initial treatment and repeated follow-up action is required. Depending on the situation, the decision to use specific control measures should be taken as part of a 5-year programme. Chemical methods should be considered as part of a wider control programme only where eradication is essential, or the site is not JNCC (2004) Common Standards Monitoring Guidance for Lowland Grassland Habitats. Version February Integrated Pest Management in Nature Conservation 77

78 easily accessed. It should be noted that an effective bracken control strategy will usually involve a variety of methods (see Figure 7) Non-chemical control Non-chemical methods of bracken control are generally more labour intensive and methods such as cutting can be less effective than the use of pesticides over large areas. The decision tree will assist with selecting the most appropriate technique. Intrusive methods such as cutting and rolling should not be carried out when breeding birds are present, or where repeated use may present a risk to other nontarget organisms. Cutting Cutting is unlikely to completely eradicate bracken; however with persistent use it will control populations to more manageable levels. For effective control, bracken must be cut at least twice in the first year (May/June and July/August) and at least once every year for the next 5 years. Where stands are particularly dense and vigorous, it may be necessary to cut/flail/roll at least three times per year to ensure effective control. Cutting can be carried out by hand using thin metal or wooden whips as well as bladed tools. Cutting is generally less effective than rolling as the cut plant surfaces heal quickly. Rolling Rolling is typically carried out to crush young bracken fronds that emerge in the spring. For an effective strategy, rolling will need to be carried out again in the same year, usually in early august. As with other non-chemical methods, persistence over a number of years is required to manage the problem effectively. Rolling weakens the plant by bruising the stems and causing them to bleed. Small scale rollers are available and usually towed behind 4x4 vehicles. For inaccessible areas, specialist contractors are also available using horse-drawn rollers. Use of livestock over winter Overwinter grazing of bracken areas by livestock can be an effective strategy to break down an infestation. The basic principle rests on the livestock breaking up the bracken litter and exposing the underground rhizomes to frost damage through poaching. Livestock grazing can be used as part of a non-chemical control strategy, often complementing cutting or rolling over spring/summer. Livestock grazing must be carefully managed on nature conservation sites, particularly where vegetation of high conservation value, archaeological remains or susceptibility to soil erosion is a characteristic of the site. Pigs have been used as bracken grazers successfully in the past, with results showing that they specifically target bracken over other species, uprooting the rhizomes which are then desiccated and die. The main consideration when grazing pigs is that too much bracken can lead to a shortage of thiamine (vitamin B) in non-ruminants. To this end, it is necessary to monitor the effect grazing is having on pigs, and provide additional feed such as pig nuts as a staple part of the diet. Another welfare consideration relates to the proliferation of ticks in dense bracken stands. Any animal grazing in bracken should be routinely checked and ticks removed in the correct manner. When grazing, pigs are likely to cause extreme ground disturbance and should not be used on sensitive sites such as those at risk of erosion. Integrated Pest Management in Nature Conservation 78

79 What is the level of bracken cover on the site? High: bracken is the dominant species at the expense of other desired species How large is the area to be controlled? Medium/low: patches of bracken in protected areas/valuable habitats. Low: Patches of bracken on areas susceptible to erosion or of little conservation value. Large > 50m2 Small < 50m2 No immediate action required. Site has topographical or other constraints which prevent the use of a vehicle. Site is of archaeological importance. Hand cutting most severely affected areas. Use of livestock over winter. Burning bracken litter. Monitor bracken for spread and be ready to control if spread becomes a problem. YES NO Is area of plants to be controlled very large and/or difficult to access? Cutting/flailing (vehicle mounted) Rolling bruising Use of livestock over winter. Burning bracken litter. YES NO Review the strategy; was infestation controlled? YES Aerial spraying Weed wiper Spot treatment Selective spraying with knapsack Monitor occurrence of infestation and be ready to control if problem returns. Figure 7: A decision tree to guide the selection of methods to control bracken. Integrated Pest Management in Nature Conservation 79

80 Burning bracken litter Burning bracken litter does not achieve control of vegetation, but may be used where deep bracken litter prevents recovery of other vegetation. This should only be used as a follow up to control methods to aid recovery of a site after removal of a dense stand of bracken and measures to establish desired vegetation should be in place to prevent colonisation by ruderal species. Hand pulling Hand pulling is seldom used as part of a bracken control strategy, largely due to the labour intensive nature of the work (especially for a dense stand). Nevertheless, hand pulling can be an effective control strategy for smaller patches of bracken and should not be completely discounted. Where hand pulling is carried out, adequate protective equipment such as gloves should be worn to prevent cuts and scrapes Chemical control Choice of herbicide Foliar spray with glyphosate should generally be avoided due to non-target effects, unless no other species are present, i.e. very dense bracken with a deep litter layer. Even then wiping is normally preferable. Asulam, the only selective herbicide for controlling bracken, which can be applied from the air, has been taken off the market. An emergency authorisation for 120 days has been given over the last few years however. The Bracken Control Group provides regular updates on developments at Herbicide applications can be made through a blanket spray to the area, or more selectively with equipment such as a hand-held lance fitted to a vehicle, or handheld sprayer or weed wiper. Blanket sprays should be considered only where there are no species of conservation value which will be affected by the herbicide. Always read the product label prior to using an herbicide. Effects on non-target species Glyphosate is a non-selective herbicide that kills most plants including grasses and woody species and overall treatment should only be made where there is no risk to other vegetation. In areas of mixed vegetation, weed wiping or spot treatment would be a more appropriate method of application. Integrated Pest Management in Nature Conservation 80

81 Table 18: Bracken (Pteridium aquilinum) possible herbicides for its control. Herbicides Uses Application methods Timing Asulam Amenity, Grassland, Moorland, Forest Emergency Authorisation only for details on conditions, go to the Bracken Control Group website Foliar spray via vehicle mounted or hand-held equipment Spot gun Jul-Aug, when fronds fully expanded (minimum 3 pairs leaves) but not senescent. DO NOT cut the bracken or admit livestock for at least 14 days after spraying and preferably leave it undisturbed until late autumn. Asulam causes no visible effect to fronds in the season of application but prevents buds on the rhizomes from emerging in the following year. Follow-up treatment could be a further spray but if a significant reduction in frond numbers is seen, mechanical or spot treatment can be used. Glyphosate Unwanted vegetation, Grassland, Forest, Surfaces not intended to bear vegetation, Amenity vegetation, Land immediately adjacent to aquatic areas Weed wiper. Foliar spray via vehicle mounted or hand-held equipment. Apply at full frond expansion, usually July- August Re-evaluation and monitoring A bracken control plan typically lasts 5 years, covering the initial treatment year and subsequent annual management using appropriate methods each year to achieve and maintain control. New fronds are likely to emerge in the same season as the control treatments and the area should be checked regularly. After this, regular long term monitoring should be carried out in readiness to prevent any regrowth, checking again for new fronds arising from underground rhizomes. Points to consider are: Was the management decision correct and did the action taken have the desired results? If a treatment was used, did it work well? What were the advantages and disadvantages? Did the treatment have any beneficial or detrimental effect on the conservation interest of the site? Where the infestation on site constitutes a high risk, chemical methods may need to be considered if a programme of non-chemical control has either not been effective to ensure the desired eradication, or if non-chemical methods are impracticable for the site (for example, labour requirements, access, etc). Monitoring is key to an effective strategy. In particular, where plants represent a Integrated Pest Management in Nature Conservation 81

82 low risk and control was not necessary the infestation should be monitored to ensure it does not present a higher risk in the future. Future land use is also important and will affect the likelihood of bracken becoming dominant again in the future. In general, woodland establishment will shade out bracken in time. Future grazing should be carefully managed in order to reduce the risk of bracken regaining dominance References and sources of information Davies, G. Turner, B. & Bond, B. (2008) Weed management for organic farmers, growers and smallholders; a complete guide. Marlborough: The Crowood Press. Defra (2005) Bracken control, vegetation restoration and land management. Rural Development Service Technical Advice Note 23. Marrs, R.H. & Watt, A.S. (2006) Biological Flora of the British Isles: Pteridium aquilinum (L.) Kuhn. Journal of Ecology. 94; Natural Scotland (2008) Bracken Control- A Guide to Best Practice. Available from: Scottish Natural Heritage Information and Advisory Note No. 24. Bracken Control. The UK Pesticide Guide (annually updated) The Voluntary Initiative Environment Information Sheets on pesticides: Integrated Pest Management in Nature Conservation 82

83 3.4 IPM protocol for the control of rushes (Juncus spp.) Background Lorne Gill/SNH Rushes are an important component of damp, semi-natural grasslands and moorland fringe. They provide cover for breeding waders and invertebrates. The tussocky nature of Juncus provides shelter and structure used by non-plant eating invertebrates and for hibernation. High levels of cover can outcompete other vegetation and become too dense for breeding waders. Soft rush (J. effusus) is the main species that might need control. Rushes spread by rhizomes and have prolific seed production. They are rapid colonisers of disturbed habitat Identifying the problem There are many Juncus species that occur in a wide range of habitats. Of these, soft rush (J. effusus) is the principal species that might require control, along with some others detailed in the table below. All are native species apart from slender rush (J. tenuis), which tends to be restricted to dispersal routes along tracks and paths. Other widespread species include jointed rush (J. articulatus) and sharpflowered rush (J. acutiflorus), which are typical constituents of species-rich fen meadow and rarely require control other than grazing. Integrated Pest Management in Nature Conservation 83

84 Table 19: Rush species that might require control. Common name Soft rush Hard rush Compact rush Slender rush Scientific name J. effusus J. inflexus J. conglomeratus J. tenuis Location Marshes, ditches, bogs, wet meadows, damp woods, by water Marshes, dune slacks, wet meadows, by water. Southern distribution Marshes, dune slacks, wet meadows, by water Roadsides, tracks and pathways Soil type Acidic Neutral, calcareous clays; alluvial soils. Tolerant of saline conditions Slightly drier and less acidic soils than J. effusus Damp open ground Lifecycle Most rush species are perennials spreading by underground rhizomes Identify Rushes have green rigid erect stems and are characteristic of damp or wet habitats. They have brown or yellowish flowers in late June or July. They can be divided into 2 groups: tufted and creeping. (See Table 20) Lookalikes Rushes are fairly distinctive although they might be confused with sedges (Cyperaceae) and grasses (Graminaceae) when not in flower. Grasses have rounded, hollow stems, most sedges have rigid triangular stems whereas rushes have rounded stems that contain pith in some species. Integrated Pest Management in Nature Conservation 84

85 Table 20: Main features of rushes Common name Soft rush Hard rush Compact rush Slender rush Jointed rush Sharp flowered rush Species J. effusus J. inflexus J. conglomeratus J. tenuis J. articulatus J. acutiflorus Habit Tufted Tufted Tufted Tufted Creeping Creeping Stem height 150 cm 120 cm 100 cm 80 cm 60 cm 100 cm Leaves None None None At base of stems and as long as the stems Jointed leaves on the stem only Jointed leaves on the stem only Flowers Brown, small, clustered. From side of stem Jul- Aug from 2 nd year Brown, loose cluster, unequal stalks. From side of stem June-Aug Dark brown, tight clusters. From side of stem May-Jul Green/yellow cluster of small beads on unequal stalks, terminal Jun- Sept Brown, at least 2 whorls, terminal, Jun- Sept Greenishbrown, at least 2 whorls, terminal. Branched, Jul- Sept Set a threshold Rushes occur in waterlogged areas within a wide range of upland and lowland habitats. They provide cover for a wide range of species and are a key component of some habitats. However, large areas of soft rush are often indicative of disturbance (usually from grazing livestock) and eutrophication. If the rushes become too dense they can smother low-growing plants and reduce the area of shorter vegetation that may be important for feeding or grazing, or otherwise restrict access to these areas. The site manager should set a threshold of the population size or percentage cover of rushes that is acceptable in the individual situation. In most cases, the aim will be to reduce, but not eliminate, rush cover. When setting a threshold, key aspects to consider are: What is the risk to surrounding vegetation where rushes could become dominant in the sward? The level of infestation. The ecological benefits of rushes to the site. In designated sites, soft rush cover of less than 10% is recommended for maintaining the site in favourable condition, and control should be considered if this threshold is exceeded. This applies to a wide range of grasslands, fens and heathlands, although in some lowland meadows for example, up to 25% cover might be acceptable. In non-designated sites, higher thresholds will usually be acceptable but this needs to be judged on a site by site basis. For example, many Integrated Pest Management in Nature Conservation 85

86 rush pastures in the lowlands and the upland fringe are also important for breeding waders, but as a rule of thumb their value declines when the cover of rushes with tufted growth form exceeds 30% of the area. Similarly, species-rich rush pasture with sharp-flowered or jointed rush may be in favourable condition with up to 80% rush cover. In blanket bog and lowland raised bogs, the threshold for designated sites is only 1% because the presence of soft rush in these habitats indicates that the bog surface has been damaged. In these situations, rush control alone is unlikely to solve the problem and other habitat restoration measures will also be required. If the nature conservation value of the site is dependent on agricultural management, high cover of rushes might be detrimental if it compromises agricultural productivity to such a degree that it discourages the occupier from carrying out this management Prevention In grassland and other grazed habitats, rushes can become dominant if land is neglected or the sward is broken through poaching or reseeding. Huge numbers of seeds are present in the soil seedbank ready to germinate if the soil is disturbed. Avoid the problem by maintaining good ground cover. If stock is present, manage stocking levels to avoid under or over grazing and avoid poaching. Prevent excessive trampling by the public; consider marked walkways with hard surface paths Control The options for control consist of both non-chemical and chemical methods. Control might need to be repeated over several seasons to reduce or maintain populations below the acceptable threshold level. Chemical control should only be used where non-chemical methods have failed to achieve the desired level of control. The decision tree in Figure 8 will assist with selecting the most appropriate technique Non-chemical Non-chemical control can be effective in reducing the extent of rushes. Nonchemical methods are generally best suited to lower populations in smaller areas. Grazing Rushes are moderately tolerant of grazing. Creeping species are eaten more readily by stock than tussock forming species so grazing alone may be sufficient to keep creeping species under control. If swards are grazed when the soil is too wet to bear the weight of livestock, poaching will occur and the resultant damage may encourage further germination of rushes. Overgrazing of stock on rushes may result in poisoning and partial blindness in cattle. Integrated Pest Management in Nature Conservation 86

87 Cutting Cutting is an effective method to prevent rushes from spreading. Two cuts per season, 4-8 weeks apart, are more effective than a single cut. If only a single cut is possible, this should be done just after flowering in August. Cut close to the ground as this reduces the vigour of the rushes. Do not scalp the ground as this will stimulate germination of the seedbank. Cutting dense stands of rushes can result in swathes of cut material that favour rush regrowth rather than grasses. Remove cuttings if possible. What is the level of risk posed by rushes? High- rushes are the dominant vegetation in the sward over a large area. Medium-rushes present in large numbers on site, adjacent sites consist of poached/bare ground. Low- bare ground on site, small numbers of rushes present. Cutting of rushes, followed by grazing if appropriate for site. Introduce a cutting programme of rushes to control problem to desired level. Maintain good ground cover to prevent a high degree of spread of rushes. Review the strategyhas the infestation been controlled? NO YES Review the strategyhas the infestation been controlled? NO Consider use of herbicide. Is site suitable for the use of a vehicle? Monitor occurrence of infestation and be ready to control if problem returns. Use individual control measures such as weed burner or introduce a cutting programme. NO YES Selective treatment of plants with knapsack sprayer or similar. Selective treatment of plants with knapsack sprayer or vehicle mounted boom sprayer on tractor or quadbike. Figure 8: Decision tree to guide the selection of methods to control rushes. Integrated Pest Management in Nature Conservation 87

88 Combination of non-chemical methods Grazing after cutting can be a more effective control method than cutting or grazing alone. A combination of grazing and cutting can then be used to maintain the level of control. Grazing can also be used to create a height differential to allow subsequent control of rushes by weed-wiper application of glyphosate Chemical control Choice of herbicide MCPA and 2-4,D provide the best control of rushes either alone or in coformulation. Application should be made when the rushes are actively growing from May to early June. Alternatively rushes can be treated after cutting. Glyphosate will kill the plant and others around it. Use of a weed wiper or spot treatment with a hand lance can increase the selectivity of this herbicide. Fitting the hand lance with a guard can direct the spray to the target more accurately. Spraying with vehicle mounted equipment should be considered only where there are no species of conservation value which will be affected by the herbicide. Always read the product label prior to using an herbicide. Glyphosate is the only herbicide approved for use near water but permission should be sought from SEPA for use in this situation. Application by tractor mounted sprayer may be the most appropriate method for controlling large areas of rushes as long as the underlying terrain is suitable. Small areas can be treated using a hand lance. Fitting a guard can prevent spray reaching non-target species. A weed wiper will be the best option for nature conservation sites where a height differential has been established through cutting or grazing. Effect on non-target species 2,4-D and MCPA are selective herbicides which control a wide range of broadleaved plants but do not affect grasses. Glyphosate is a non-selective herbicide that kills most plants. Integrated Pest Management in Nature Conservation 88

89 Table 21: Rushes (Juncus spp.) - possible herbicides for their control. Herbicides Uses Application methods Timing 2,4-D Amenity grassland, Grassland, Managed amenity turf Foliar spray via vehicle mounted or hand-held equipment April to June when actively growing. Treat before flowering and cut 4 weeks after (or before) treatment to improve control. Top growth killed and weeds suppressed. Repeat treatment will be necessary. Control is improved in mixture with MCPA 2,4-D + MCPA Grassland Foliar spray via vehicle mounted equipment. Some products can be applied using hand-held equipment. Treat in April-June. Stems should be cut and removed either 4 weeks before or after treatment. Top growth killed and weeds suppressed. Repeat treatment will be necessary. Glyphosate Unwanted vegetation, Grassland, Forest, Surfaces not intended to bear vegetation, Amenity vegetation, Land immediately adjacent to aquatic areas Foliar spray via vehicle mounted or hand-held equipment. Weed wiper Rotary atomiser. Apply when actively growing from May to early June. Always contact SEPA before use in or near water. MCPA Grassland Foliar spray via vehicle mounted equipment. Some products can be applied using hand-held equipment. Spray in April to June. Cut and remove stems either four weeks before or after treatment. Top growth killed and weeds suppressed, repeat treatment will be necessary. Control is improved in mixture with 2,4-D Integrated Pest Management in Nature Conservation 89

90 3.4.5 Re-evaluation and monitoring Continue to monitor existing rush tussocks for regrowth and disturbed areas for establishment of new plants. Monitoring will need to be continued for several years due to the abundance of buried seed and its long-term viability. Re-evaluation should be carried out in the context of informing a control programme for the next year. Points to consider are: Was the management decision correct and did the action taken have the desired results? If a treatment was used, did it work well? What were the advantages and disadvantages? Did the treatment have any beneficial or detrimental effect on the conservation interest of the site? Where the infestation on site constitutes a high risk, chemical methods may need to be considered if a programme of non-chemical control has either not been effective to ensure the desired eradication, or if non-chemical methods are impracticable for the site (for example, labour requirements, access, etc). Monitoring is key to an effective strategy. In particular, where plants represent a low risk and control was not necessary, the infestation should be monitored to ensure it does not present a higher risk in the future References and sources of information Bond W, Davies G, Turner RJ (2007) The biology and non-chemical control of rushes (Juncus spp.) Crofts A & Jefferson R G (1999) The Lowland Grassland Management Handbook, Chapter 7 RSPB Rush management. SRUC (2012) Weed management in grassland. Technical Note TN643 sland The Fen Management Handbook (2011), Editors A. McBride, I. Diack, N. Droy, B. Hamill, P. Jones, J. Schutten, A. Skinner, and M. Street. Scottish Natural Heritage, Perth The UK Pesticide Guide (annually updated) The Voluntary Initiative Environment Information Sheets on pesticides: Integrated Pest Management in Nature Conservation 90

91 3.5 IPM protocol for the control of purple moor-grass (Molinia caerulea) on heather moorland Background Graham Sullivan/SNH Purple moor-grass (Molinia caerulea) is a natural component of a wide range of wet habitats, especially on acidic or peaty soils. It provides structure for invertebrates and is the food plant of the Chequered Skipper butterfly in Scotland. It is a deciduous tussock-forming grass which is strongly competitive in early summer. It has some value as early bite in spring for cattle and sheep on moorland due to its early emergence. It can dominate degraded moorland and prevent heather regeneration Identifying the problem Purple moor-grass is a native species and an important component of many upland and lowland habitats. It can become dominant on wet heath and blanket bog that has been degraded by heavy grazing pressure or frequent muirburn, at the expense of dwarf shrubs (particularly heather, Calluna vulgaris) and other plant species including graminoids such as deergrass (Trichophorum cespitosum) and cottongrasses (Eriophorum spp.). In moorland restoration schemes where there is extensive cover of purple moor-grass, reducing (or eliminating) grazing pressure or burning frequency, or changing the grazing regime can be successful if heather or other moorland species are still widespread in the plant community. However, if these species are scarce or absent, and the vegetation is dominated by purple moor-grass tussocks, more targeted control of purple moor-grass might be necessary to reduce its competitiveness and to create gaps for re-establishment of heather and other species. This protocol addresses the specific situation where purple moor-grass control is required as part of a heather restoration scheme. Integrated Pest Management in Nature Conservation 91

92 Lifecycle Purple moor-grass is a perennial grass that dies back after flowering and seeding in the autumn. It spreads vegetatively and by seed Identify Purple moor-grass is a deciduous grass that it is easily recognisable when it forms extensive patches and large tussocks in moorland. In winter, it produces large amounts of straw coloured leaf litter. When dispersed amongst other plant species, it can be less obvious but is characterised by broad, flat leaves and long, narrow purple inflorescences. Table 22: Main features of Purple Moor-Grass Plant An erect plant, typically up to 45-90cm tall. Stem Leaves Single green stems from the base sometimes form a tussock. Each stem has a single node around 5cm or less from the base. The ligule is a ring of hairs around the stem. Flat greyish 3-6mm wide arising from the base or from the node. The leaves detach from the plant in winter and lie in curly straw-coloured heaps. Flowers A spike-like panicle with the spikelets being commonly purple, anthers purple/brown. Flowers July-September Lookalikes Grasses such as sweet vernal-grass (Anthoxanthum odoratum) or bent-grasses (Agrostis spp.) are superficially similar when not in flower but do not form dense tussocks or large amounts of litter. Mat-grass (Nardus stricta) can dominate drier, degraded moorland but has narrow, wiry leaves and forms smaller tussocks Set a threshold The site manager should set a threshold of the percentage cover of purple moorgrass that is acceptable in the individual situation. As a rule of thumb, if its cover in open moorland is greater than 50-75% then the habitat is likely to benefit from reducing its cover. In lowland heathland, maximum thresholds of purple moorgrass cover have been defined for favourable condition in designated sites, being Integrated Pest Management in Nature Conservation 92

93 33% or 66% respectively in dry and wet heaths. However, in non-designated sites, lower thresholds will often be acceptable, depending on the overall habitat condition and restoration objectives. On large sites with multiple owners, there might be a disproportionate area of purple moor-grass on one or more holdings, in which case individual owners might be justified in reducing its extent. Where the intention is to re-introduce heather into the plant community or to encourage regeneration of degraded heather, then control of purple moor-grass should be considered Prevention Purple moor-grass can become dominant as a result of heavy grazing by herbivores and/or too frequent burning. Maintaining heather moorland in good condition can be achieved by: Applying appropriate grazing regimes (see below) and good stock management. Avoiding burning especially in heather-grass mosaics. If burning is necessary, follow good muirburn practice and control following summer growth by light sheep grazing. Following good deer management practice Control The options for control consist of both non-chemical and chemical methods. Control will need to be repeated over several seasons to reduce or maintain cover below the acceptable threshold level. Chemical control should only be used where non-chemical methods have failed to achieve the desired level of control. Chemical control will seldom be applicable on blanket bog because peat-forming species such as cotton grasses might also be affected. Figure 9 can assist with selecting the most appropriate technique when purple moor-grass is dominant or co-dominant with heather. In addition to controlling purple moor-grass, a restoration scheme will include measures to re-establish heather and / or other desirable moorland species. Revegetation might be achieved by allowing plants already present in the vegetation to spread, or otherwise by creating bare ground and adding heather seed or relying on heather establishing from the seed bank Non-chemical On heather moorland, non-chemical control through a combination of grazing and cutting and the absence of burning, has been shown to be the most successful approach. Options for chemical methods are relatively limited and little information is available on the effects of the chemicals on non-target species. 28 For examples of restoration techniques see Integrated Pest Management in Nature Conservation 93

94 Purple moor-grass dominant or co-dominant with heather Shallow peat or mineral soil Deep peat / blanket bog Cattle available YES NO Cut with low ground pressure vehicle and graze re-growth with sheep at low stocking density Cut with low ground pressure vehicle and graze regrowth with sheep at low stocking density Monitor results and repeat treatment if necessary Summer-only grazing with cattle at appropriate stocking density Monitor results was control successful? NO YES Consider herbicide application and graze any regrowth with sheep at low stocking density Continue monitoring and repeat treatment if necessary Figure 9: A decision tree to guide the selection of methods to control purple moor-grass. Grazing If heather or other heath or bog species are still present in the vegetation, selective grazing can be used to alter competitive interactions in favour of these but this will only be successful in the absence of burning. A particular grazing regime can either suppress purple moor-grass or reinvigorate heather but a combination of regimes might be needed to achieve both effects. The most appropriate grazing regimes will be dependent on site conditions and availability of livestock. Flexibility in grazing regime and regular monitoring of vegetation change may be needed to achieve the objective of increased heather cover. The options for grazing management are as follows: Cattle selectively graze patches of purple moor-grass, reducing its vigour. Two months summer grazing with cattle at up to 0.75 cows/ha can suppress purple moor-grass sufficiently to enable heather to out-compete it. This high stocking density is likely to be most effective in areas where purple moor-grass is Integrated Pest Management in Nature Conservation 94

95 dominant (c. 40% cover or more) and where heather is present in the understorey and/or the seed bank. Increase in heather cover is likely to be slow, and significant change may not be observed for 5-10 years. Cattle grazing at up to 0.5 cows/ha for 2 months will remove a significant biomass of purple moor-grass and may reduce its rate of increase in the long term (i.e. >10 years). Where purple moor-grass is dominant, this low stocking rate is unlikely to be sufficient to control it. Where it is co-dominant with heather, then this low stocking rate should be sufficient to enable heather to thrive and eventually overtop purple moor-grass. In similar areas, a rotational (e.g. grazing 1 year in 5) cattle-only grazing regime using up to 0.75 cows/ha, may achieve the same effect. Cattle should not be used on blanket bog unless there is a dense mat of purple moor-grass that needs to be broken down and bog species, especially Sphagnum mosses, have already disappeared. On intact blanket bog, cattle are likely to damage the fragile peat substrate. Mature heather is also vulnerable to cattle trampling, so a lower stocking rate should be used where significant patches of mature heather remain. Grazing sheep at up to 1.0 ewes/ha (with at least 25% reduction in stocking rate during November to February, or removing completely) will enhance the vigour of dwarf shrubs, but other measures will also be needed to reduce the competitiveness of purple moor-grass. Lower stocking densities will be appropriate on blanket bog and on exposed or high altitude sites. If purple moor-grass is present at low cover amongst other grasses or sedges (up to c. 10%), grazing sheep in summer only at low stocking densities will enhance the vigour of heather and increase its competitiveness with purple moor-grass. Cutting Cutting in combination with grazing is effective in reducing purple moor-grass. Cut purple moor-grass up to three times in spring and autumn, preferably during dry weather when the plants are more susceptible. Graze the vegetation with cattle or sheep for up to two months in subsequent years, while there is still some regrowth. Biological control There are no biological control alternatives currently available Chemical control Choice of herbicide Chemical control can be used when the area to be treated has a high cover of purple moor-grass and has low levels of other beneficial species. There are currently no pesticide products specifically approved for use on heathland or moorland. Neither of these habitats is currently a category in the crop hierarchy published by Chemicals Regulation Directorate, though the hierarchy is currently under review and moorland may be included in future. As a consequence, to use an approved product on heathland or moorland, an application for an Extension of Authorisation for minor use (EAMU) (formerly known as Specific Off-Label Approvals - SOLA s ) will be needed. Integrated Pest Management in Nature Conservation 95

96 A range of graminicides has been evaluated for the control of purple moor-grass. All of the herbicides give short term control, up to 1 year which may provide enough time for other species to spread into the bare patches created, if the species are already present in the sward or if seed is added. Glyphosate will give complete control of purple moor-grass in the short-term but further ingress from surrounding areas or from the seedbank can occur. Repeated treatments may be needed to keep levels below threshold. Glyphosate will kill the plant and others around it. Use of a weed wiper or spot treatment with a hand lance can increase the selectivity of this herbicide. Fitting the hand lance with a guard can direct the spray to the target more accurately. Application by tractor mounted sprayer may be the most appropriate method for controlling large areas of purple moor-grass as long as the underlying terrain is suitable and there is minimal risk to non-target species (see below). Small areas can be treated by hand-held lance fitted to a vehicle mounted or knapsack sprayer. Applications can be made using a hand held weed wiper in areas where other sensitive vegetation is present. Purple moor-grass litter will need to be removed by raking or burning and reseeding of heather or other species will be necessary to re-establish vegetation cover. Spraying with vehicle mounted equipment should be considered only where there are no species of conservation value which will be affected by the herbicide. Always read the product label before using a herbicide. Table 23: Purple moor-grass (Molinia caerulea) - possible herbicides for its control. Herbicides Uses Application methods Timing Cycloxydim Land temporarily removed from production Foliar spray via vehicle mounted or hand-held equipment. Before first node detectable Glyphosate Unwanted vegetation, Grassland, Forest, Surfaces not intended to bear vegetation, Amenity vegetation, Land immediately adjacent to aquatic areas Foliar spray via Vehicle mounted or hand-held equipment. Weed wiper Rotary atomiser Spring/summer, when grass actively growing. Grass with at least 4-5 new leaves & at least 10 cm tall. Effect on non-target species Glyphosate is a non-selective herbicide that kills most plants including grasses and heather. Cycloxydim is a graminicide and has little effect on broad-leaved plants including heather. They have varying effects on grasses and this varies with growth stage and conditions at application; for most perennial grasses the effects will be transitory as for purple moor-grass. Red fescue is resistant to cycloxydim. Integrated Pest Management in Nature Conservation 96

97 3.5.5 Re-evaluation and monitoring Continue to monitor the area. Re-evaluation should be carried out in the context of informing a control programme. Control by altering the grazing regime will take several years to be effective although chemical control can produce results within the same growing season. Purple moor-grass tussocks are particularly persistent. Points to consider are: Was the management decision correct and did the action taken have the desired results? If a treatment was used, did it work well? What were the advantages and disadvantages? Did the treatment have any beneficial or detrimental effect on the conservation interest of the site? Where the infestation on site constitutes a high risk, chemical methods may need to be considered if a programme of non-chemical control has either not been effective to ensure the desired eradication, or if non-chemical methods are impracticable for the site (for example, labour requirements, access, etc). Monitoring is key to an effective strategy. In particular, where plants represent a low risk and control was not necessary, the infestation should be monitored to ensure it does not present a higher risk in the future References and sources of information Crofts A & Jefferson R G (1999) The Lowland Grassland Management Handbook, Defra (2007) Controlling Purple Moor-grass (Molinia) in BD1228 Determining Environmentally Sustainable and Economically Viable Grazing Systems for the Restoration and Maintenance of Heather Moorland in England and Wales. English Nature (2004) Purple moor-grass and rush pastures Goodyear J, Tallowin J Bullock J & Smith R (2001) Grazing purple moor grass and rush pastures. Enact 94(4) Natural England (2010) Illustrated guide to purplemoor grass and rush pastures Marrs R.H., Phillips J.D.P., Todd P.A., Ghorbani J. & Le Duc M.G. (2004) Control of Molinia caerulea on upland moors. Journal of Applied Ecology 41, The UK Pesticide Guide (annually updated) The Voluntary Initiative Environment Information Sheets on pesticides: Integrated Pest Management in Nature Conservation 97

98 3.6 IPM protocol for the control of scrub Background Jane Mackintosh/SNH The JNCC definition of scrub is: all stages from scattered bushes to closed canopy vegetation, dominated by locally native or non-native shrubs and tree saplings, usually less than 5 m tall, occasionally with a few scattered trees. Scrub can form an important habitat mosaic with other vegetation types, and some types of scrub are important habitat in their own right. Scrub is a food source for many invertebrates in addition to providing structure and shelter. Certain types of scrub can be highly invasive and might require control if they are encroaching on valuable habitat Identifying the problem Identify Scrub habitats with intrinsic value such as montane scrub, juniper (Juniperus communis) stands or wind-pruned coastal scrub are normally managed to conserve their value. The types of scrub that may cause concern are species that have invasive tendencies, which can reduce the extent and condition of other habitats, particularly in the lowlands. Species most likely to require control in certain circumstances include gorse (Ulex europaeus), blackthorn (Prunus spinosa), hawthorn (Crataegus monogyna), birch (Betula spp.) and willow (Salix spp.). In addition, there may be non-native species such as rhododendron or sycamore (Acer pseudoplatanus) which may need to be controlled. Of particular concern is sea-buckthorn (Hippophae rhamnoides), which is an invasive non-native species on coastal sand dunes Planning for management of scrub In most circumstances, native shrub species will be beneficial to wildlife. The extent of scrub control required will be very much dependent on individual sites. The balance of scrub species removed/retained should reflect the ecological Integrated Pest Management in Nature Conservation 98

99 characteristics of the locality. There are some selective advantages in ensuring that there is a flowering sequence of different flowering scrubs. This will be dictated by the conservation objectives for the site, and the value of the scrub itself. As a guide the following factors dictate the conservation value of scrub (Table 24). Table 24: Assessing conservation value of scrub. Adapted from Day et al. (2003). Factor Scrub with high conservation value Scrub with low conservation value Species Native shrub or tree sapling species. Non-native species within scrub. Composition Age & structure Habitat context Associated flora & fauna High diversity of shrub or tree sapling species. Scrub with plants of differing age and physical structure. Diverse mosaic with scrub and associated open habitat. Diverse range of associated species. Low diversity of shrub or tree sapling species. Scrub with plants of similar age and physical structure. Scrub in continuous blocks. Few associated species Set a threshold The decision on whether to control or enhance an area of scrub will depend on achieving a balance between its conservation value and any potentially negative effects on other habitats. Setting a threshold for the optimum amount of scrub on a particular site will require a complex set of judgements to be made and will be key to an IPM approach to scrub control. A guide to assessing the need for management is given in Figure 10. For designated sites, a range of maximum cover values of scrub are recommended to maintain a site in favourable condition. These vary from 10% in most fens, bogs and upland grasslands, to 20% in upland heaths and 25% in rocky habitats. In lowland grasslands, a maximum of 5% in combination with bracken is recommended. Integrated Pest Management in Nature Conservation 99

100 SCRUB Enhance Priority scrub composed of species of nature conservation value. Consider: A: Increasing extent if scrub of conservation value. B: Improve quality if priority scrub in poor condition Enough priority scrub in favourable condition, needs maintenance Scrub competing with other priority habitats, needing reduction Control Scrub composed of species with invasive tendencies, encroaching or having potential to encroach and reduce the extent of other valuable habitats. Figure 10: A guide to assessing the need for management of scrub. Adapted from Day et al. (2003) Prevention A key aspect of any management strategy for scrub is to ensure that beneficial levels of scrub are retained, whilst control is applied only when necessary. Good management practice involves continual monitoring of scrub levels, and where necessary applying low key control methods such as cutting of individual plants or using browsing animals to keep scrub in check and prevent further encroachment Control Complete eradication of scrub will sometimes be necessary if the aim is to remove a non-native invasive shrub species or to maximise the area of the habitat being invaded. In many cases however, the aim will be to maintain scrub at its current level or to reduce it to an acceptable level. Intrusive methods of control should be done in autumn or early winter to minimise disturbance to wildlife. The decision tree in Figure 11 can be used as a guide for control Non-chemical Livestock Grazing Livestock grazing (i.e. where browsing of shrubs is encouraged) can be an effective strategy to shape stands of scrub and create a good balance between scrub and open habitat. Livestock grazing on open ground can also be used to prevent colonisation by scrub. Wild herbivores such as deer and rabbits can also help to reduce expansion of scrub but the effects of uncontrolled browsing will need to be monitored closely. The level of control required will dictate to what extent, and for how long grazing is carried out. Grazing is not a long term solution for control as Integrated Pest Management in Nature Conservation 100

101 regrowth is likely to occur from remaining stems. In this case grazing is seen mainly as a maintenance technique for retaining existing levels of scrub, and if necessary reducing its extent. Grazing a site seldom eradicates established scrub unless it is old, or if very high stocking rates are applied. Prolonged high stocking rates are likely to damage ground flora which may be of conservation interest. What is the composition of scrub on site? Scrub encroaching on valuable habitats. Scrub provides a valuable habitat on site but is encroaching at the expense of other valuable habitats. Priority scrub on site composed of native species with a high diversity of plants and ages/physical structures of plants. Consider whether scrub needs to be reduced or maintained at current levels. Reduction of scrub Scrub should not be controlled, assess the state of scrub species and if necessary consider enhancing or increasing extent. Site has topographical or other constraints which prevent the use of a vehicle. Maintain at current levels YES Cutting- hand held equipment. Stump removal - hand held equipment. Review strategy; has desired control been achieved? NO Cutting- heavy machinery e.g. mower or mulcher. Grubbing out. Stump removal - winching. Where complete eradication of large plants/scrubs is required consider treating cut stumps with a herbicide. Graze areas with a suitable breed of animal which will limit the further spread of scrub. Maintenance of a hand weeding or cutting regime to prevent encroachment. Continue to monitor site and maintain scrub at current levels through frequent management. NO Consider use of a herbicide. Targeted application to cut stumps or foliage. Non-target application should be avoided where possible. Figure 11: A decision tree to guide the selection of methods to control scrub Integrated Pest Management in Nature Conservation 101

102 When designing a grazing strategy, choice of species and/or breed of grazing animal is important and will depend on the site characteristics and availability of livestock and associated infrastructure. Sheep, cattle and ponies will graze vegetation making them an effective strategy for reducing further spread of vegetation. Ponies can also be used. Cattle will often browse growth from the current year. Goats habitually browse vegetation, and pigs do little grazing or browsing but will root in the soil. See the Breed Profiles Handbook 29 for further guidance on animal selection; in all cases selection of breed will be determined by vegetation present on site, the desired balance between scrub and open vegetation and other site characteristics such as topography. Water level management Where scrub is present on wetlands, lowered water levels often result in further encroachment. Scrub species may colonise wetlands after water levels recede, but are killed once the area is subject to re-wetting. It is important to distinguish between carr woodland, which is a BAP Priority Habitat composed of species such as alder, birch and willows, and scrub which has invaded wetland as a consequence of undesirable changes in hydrology. Scrub management by altering site hydrology should only be attempted after assessing the effects on the habitat and the surrounding area. It will be important to ensure that only the target site is affected by raised water levels, especially if adjacent habitats are of particular conservation importance. Where changes to water management on the site are planned, the Scottish Environment Protection Agency must be contacted in case permissions are needed. Hand weeding Hand weeding can be an effective strategy for removing scrub seedlings or young plants. Hand weeding is labour intensive, and can be slow. Despite this, it can be a cost effective means to remove scrub at an early stage, rather than tackling bigger stands later on. Cutting Cutting of scrub can be carried out either by hand or through the use of machinery depending on the specifics of the site. A cutting strategy will usually require follow up treatments to prevent regrowth, which can be rapid from the remaining stumps. If eradication of the scrub is desired, follow up treatments such as grazing and stump removal can be used. Cutting works well as a measure to reduce the extent of scrub and maintain it at an acceptable level. Cuttings will need to be removed from the site or destroyed by chipping or burning away from sensitive areas. If a high level of control is desired, chemical treatment to cut stumps immediately after cutting may be required. Stump removal Stump removal can provide a long term solution where eradication of vegetation is required. The technique is best used after cutting, or similar to uproot the plant and prevent regrowth. It can be carried out with a variety of equipment, from hand tools to equipment such as grinders, chainsaws and machinery designed for winching Integrated Pest Management in Nature Conservation 102

103 Disturbed bare ground created by stump removal operations can be recolonised by scrub or by ruderal species and restoration of suitable vegetation cover might need to be considered. Grubbing out Grubbing out refers to removal of scrub with mechanical excavators, and can be a cost effective and relatively quick method for large scale removal. The use of excavators creates high levels of disturbance and may not be suitable on sensitive conservation areas, and skilled operators are needed to remove scrub without damaging non-target areas. As with stump removal, restoration of vegetation in disturbed areas might be required Chemical control Choice of herbicide There are a few herbicides available for the control of scrub. Glyphosate will kill other plants. Use of a weed wiper or spot treatment with a hand lance can increase the selectivity of this herbicide. Fitting the hand lance with a guard can direct the spray to the target more accurately. Glyphosate can also be applied in a freshly cut stump or through tree injection. Spraying with vehicle mounted equipment or aerial spraying will be considered only where there are no species of conservation value which will be affected by the herbicide. Always read the product label prior to using an herbicide. Cut stump application Cut stump application involves applying an approved herbicide to the freshly cut stump on the same day of cutting. Application straight after cutting will result in immediate uptake but delaying application will slow uptake and rainfastness. Applications can be made with a hand-held lance, spot gun or paintbrush. The technique is shown to be highly effective if a hole is drilled into the stump in which the herbicide can form a reservoir. If multiple applications of herbicide are being made in the same area, a dye should be added to the chemical so operators can see which stumps have been previously treated. Foliar regrowth application New shoot growth from cut or flailed stumps should be targeted after it has had at least one full growing season to develop. The young growth allows for improved penetration of the herbicides. All foliage should be treated as there may be no lateral translocation of herbicide within the plant. Treatment should occur before the foliage reaches a height of 1.3 m the safe height for overall spraying using hand-held applicators without undue risk to the operator. Herbicide kill is often incomplete and repeat applications may be necessary, so monitor annually. Integrated Pest Management in Nature Conservation 103

104 Table 25: Scrub - possible herbicides for its control. Herbicides Uses Application methods Timing Clopyralid + triclopyr Amenity grassland, Grassland Foliar spray via vehicle mounted or hand-held equipment. Tractor mounted weed wiper (SOLA). Do not apply using hand-held rotary atomiser equipment. Spray between June and August when actively growing and before senescence. All foliage should be wetted to ensure complete kill. 2,4-D + dicamba + triclopyr Grassland, Forest, Natural surfaces not intended to bear vegetation, Amenity grassland Foliar spray via vehicle mounted or hand-held equipment Apply after the first flush of spring growth between July and September. Cut stump treatment via a hand-held lance Apply after felling to the outer rim of the stump. Any regrowth should be treated with a follow up spray. Glyphosate Unwanted vegetation, Grassland, Forest, Surfaces not intended to bear vegetation, Amenity vegetation, Land immediately adjacent to aquatic areas Foliar spray via vehicle mounted or hand-held equipment. Weed wiper Rotary atomiser Apply when sufficient leaf growth is present between early May and late September Addition of Mixture B NF will improve control of waxy leaved shrubs such as ivy, broom, gorse and laurel Cut stump treatment hand-held lance, paintbrush, clearing saw with built-in applicator Apply when dormant between November and March to freshly cut stumps. Tree injection spot gun Treat during autumn and winter. Neat glyphosate is injected into the stem through a fresh hatchet cut Triclopyr Unwanted vegetation Foliar spray via vehicle mounted or hand-held equipment. Do not apply by hand held applicator with rotary atomiser. Mixed with water, apply between June-September, ensure all foliage is wetted. Mixed with diesel. Winter shoot sprays between October and March. Ash buckthorn, hawthorn and oak are most susceptible Integrated Pest Management in Nature Conservation 104

105 Herbicides Uses Application methods Timing Triclopyr Cut stump hand-held lance spot gun or paintbrush Stem treatment Basal bark spray stems <30cm Frill girdling stems >30cm Mixed with water, diesel or paraffin, Apply any time of year except when sap is flowing in the spring. Apply by hand lance to bottom 30-45cm of cut stem, saturating to run-off during the late growing season Penetrate the cambium with a ring of downward sloping or overlapping cuts, near to ground level. Apply the herbicide mixed in diesel or paraffin oil above the cuts so it runs down into them. Apply during late growing season. Tree injection Inject undiluted or 1:1 herbicide at 7.5cm spacing around the trunk. Optimum timing is summer or autumn. Overall foliar application Application of herbicides should be made to all live foliage so access to the whole plant is needed. Applications should be restricted to bushes less than 1.3m in height for ease of application and operator safety. Stem treatment Stem treatment is carried out on scrub where stem diameter is greater than 3 cm. The treatment involves damaging stems using a small axe, mattock or similar implement or drilling downwards sloping holes into larger stems to act as a reservoir for the chemical. For glyphosate, a cut or hole is needed for every 10 cm diameter of the trunk. For triclopyr, injection should be made into cuts every 7.5 cm around the trunk. Effect on non-target species Glyphosate is a non-selective herbicide that kills most plants including grasses and woody species. Overdosing trees when stump treating or chemical thinning can result in nearby trees being affected. The probability of this occurring is highest when the trees are the same species and are connected by mycorrhyzal fungi. Triclopyr, clopyralid, 2,4-D and dicamba are selective herbicides and control a wide range of broad-leaved plants. They have little or no effect on grasses but the mixture of 2,4-D, dicamba and triclopyr can cause a temporary suppression of bents (Agrostis spp.) and Yorkshire fog (Holcus lanatus). Integrated Pest Management in Nature Conservation 105

106 3.6.5 Re-evaluation and monitoring Continue to monitor the area, paying particular attention to regrowth from treated stumps and for regeneration of seedlings in bare areas exposed where the scrub canopy has been removed. Suckering species such as blackthorn are also likely to regenerate from rootstock. Re-evaluation should be carried out in the context of informing a control programme for the next year. Points to consider are: Was the management decision correct and did the action taken have the desired results? If a treatment was used, did it work well? What were the advantages and disadvantages? Did the treatment have any beneficial or detrimental effect on the conservation interest of the site? Where the infestation on site constitutes a high risk, chemical methods may need to be considered if a programme of non-chemical control has either not been effective to ensure the desired eradication, or if non-chemical methods are impracticable for the site (for example, labour requirements, access, etc.). Monitoring is key to an effective strategy. In particular, where plants represent a low risk and control was not necessary, the infestation should be monitored to ensure it does not present a higher risk in the future References and sources of information Day, J. Symes, N. Robertson, P. & Bacon, J. (2003) The scrub management handbook: guidance on the management of scrub on nature conservation sites. Mortimer, S.R., Turner, A.J., Brown, V.K., Fuller, R.J., Good, J.E.G., Bell, S.A., Stevens, P.A., Norris, D., Bayfield, N., Ward, L.K., (2000), The Nature Conservation Value of scrub in Britain, JNCC Report No. 308, JNCC Peterborough. The Breed Profiles Handbook: A Guide to the Selection of Livestock Breeds for Grazing Wildlife Sites. The Grazing Advice Partnership. The UK Pesticide Guide (annually updated) The Voluntary Initiative Environment Information Sheets on pesticides: Integrated Pest Management in Nature Conservation 106

107 Part 4 Other pest, disease and vegetation management Integrated Pest Management in Nature Conservation 107

108 4.1 Vegetation management around visitor facilities Background Lorne Gill/SNH Amenity land in conservation areas is that intended to provide a facility for visitors. This includes areas such as car parks, hardcore paths and walkways and visitor centre areas in land such as National Nature Reserves (NNRs) and similar sites frequented by the public. Typically it is vegetation control, rather than pest or disease management that is required in these areas to provide a suitable and safe area for visitors Problems posed by vegetation in visitor facilities The main issue will be invasive vegetation and ruderal species colonising bare ground or cracks in hard surfaces. This vegetative growth cause structural damage to hard surfaces and present a safety risk to visitors. Keeping vegetation to a manageable level negates a lot of these problems. In urban areas, such vegetation is often controlled because it is perceived as unsightly. However, in nature conservation sites public perceptions will be different and there is likely to be greater understanding of the value to biodiversity of annual and ruderal plants, and therefore a higher level of tolerance. In reality, control may only be required where plants prevent a health hazard, or have the potential to do structural damage to sites. Within large grassy areas in land such as car parks, mowing and strimming vegetation is likely to predominate. However in areas where these methods are not suitable due to physical constraints, herbicides are often used. Where invasive species such as Japanese knotweed have the potential to damage hard surfaces or other structural features or could potentially disperse to the nature conservation site itself, these should be controlled at an early stage. Integrated Pest Management in Nature Conservation 108

109 Routine structural maintenance of infrastructure, such as filling in cracks and potholes in hard surfaces, maintaining drains, etc. will be the main way of preventing major problems developing Implementing IPM around visitor facilities The aim of using an IPM approach in amenity areas should be to minimise the use of pesticides whilst managing problems at an acceptable level. A key determinant of a control strategy in amenity areas is public safety, and using approaches that are less intrusive are usually preferred Where control may be required Control of vegetation (over and above the standard cutting of grass) in amenity areas should be considered if one or more of the statements below hold true: Vegetation has the potential to cause structural damage to hard surfaces or other infrastructure near the site. Vegetation growth causes a public health hazard through risks of trips, slips and falls or obstruction of view to vehicles. Invasive vegetation is present (refer to specific protocols if applicable). Drainage channels being blocked. There is potential for dry or dead vegetation to cause a fire hazard. Vegetation may provide a suitable environment for commensal rodents. The extent to which control is a priority must be assessed by the land manager and appropriate action taken. The setting of any control strategy should have clear and realistic management objectives for the site Choosing between chemical and non-chemical control methods The choice between using a chemical or non-chemical method to control vegetation in amenity situations should be predicated on a number of factors. Non-chemical methods of control should be considered where: Problems are small scale, and isolated (such as small patches of weeds). Members of the public are continually present in large enough numbers where the spraying of pesticide may constitute a health hazard, or when visitor movements cannot be managed to prevent contact with treated areas. In such situations it may be safer to use a non-chemical method or apply herbicide either late at night or early in the morning. The area has species of high conservation value close to the target. Nonchemical methods such as hand pulling may be preferred to prevent damage from spray drift. The use of pesticides may present a risk of watercourse contamination; in all cases the label guidance should be followed. Pesticides should not be applied near drains, or where runoff from surfaces (particularly hard surfaces) could put watercourses at risk. Non-chemical methods are preferred to prevent pollution. Integrated Pest Management in Nature Conservation 109

110 The main factors which dictate whether pesticides are used are normally: Availability of labour: chemical control is usually less labour intensive. Less intrusive: if there is a lot of vegetation to eradicate, using large scale mechanical methods could do damage to surrounding vegetation or damage features of the site. Cost effectiveness: large scale vegetation control may be cheaper if pesticides are used rather than non-chemical methods. Any control strategy should be predicated on a stipulated goal or end point and complete eradication of unwanted vegetation may not always be the main aim Chemical control around visitor facilities Where chemical control is required on a site a number of factors should be considered to ensure best practice. The Amenity Forum provides guidance notes 19 on the amenity use of pesticides Choice of pesticide Glyphosate based products are those most commonly used to control vegetation in amenity areas, and are widely available. Glyphosate is a non-selective herbicide, and will likely kill most vegetation that it comes into contact with. Given this, selective spraying methods are often preferred. Where a particular species needs to be controlled, a selective herbicide may be a better option if it is available. Due to its widespread use in amenity areas, concerns have been raised about build-up of resistance to glyphosate in weeds here (see essential reading). Given this, it is always preferable to use a variety of pesticides rather than relying on a single active ingredient for all control Application Anyone handling pesticides in amenity should be adequately trained and hold the appropriate certificate of competence. Any sprayers used in the amenity sector should be well maintained and calibrated before use. See Appendix 1 and 2. More information on checking sprayers in amenity can be found at: Safety of public Amenity areas in conservation sites open to the public invariably will involve spraying at times when the general public may be present. The safety of the public is of paramount importance when applying pesticides and best practice principles should be observed. Complete avoidance of the general public is not always practical and as such: It is always preferable to apply pesticides in amenity areas at times when fewer people are present such as early in the morning. Spray drift should be kept to a minimum, and targeted spraying is preferable to large scale application. Wherever possible the use of low drift air induction nozzles should be used in spraying equipment, particularly on hard surfaces. Where boom spraying is carried out, use shrouds to prevent drift Integrated Pest Management in Nature Conservation 110

111 Use COSHH assessments 20 to help choose the safest chemical possible. Where large scale spraying is planned, it is important to demonstrate that all possible safety precautions have been taken including notifying the public. Warning signs should be erected with statements such as spraying in progress as well as forward notification if necessary. Any operator using pesticides in amenity areas should always be prepared to answer any questions/allay any concerns the public may have if approached. Checklist The following points should all have been considered. If not, you should question whether or not it is appropriate to apply pesticide: 1. Is it necessary to control the vegetation? Is an invasive non-native species present? Is vegetation growth presenting a health hazard to visitors? Is vegetation growth likely to cause infrastructural damage on site? Is it a necessary requirement of the site that vegetation be controlled to ensure areas do not look unsightly? 2. Could non-chemical methods be used to control the problem instead of using a pesticide, in a way that is cost effective and practical? 3. If chemical methods are used, does the equipment ensure minimum spray drift (such as controlled droplet applicator, low drift nozzles or boom shroud)? 4. Do all operators have appropriate certification for the use of pesticides, are they supervised or has advice been taken from a BASIS qualified advisor? 5. Are operators aware of the code of practice for using plant protection products, and their legal responsibilities? 6. Have appropriate controls been taken to minimise the impact of pesticides on human health and the natural environment? References and sources of information Training, qualification and personal development in Amenity: BASIS Registration Ltd: Guidance notes supplied by the Amenity Forum on the amenity use of pesticides: Integrated Pest Management in Nature Conservation 111

112 4.2 Forestry Lorne Gill/SNH Woodlands are exposed to a range of biotic pressures. For most invertebrate pests and diseases, control action is rarely necessary in nature conservation situations. However adverse effects may occur where there is a shift in the competitive balance between species. Competition from weeds can interfere with successful woodland establishment. In particular, invasive plants increase competition, kill native flora and make regeneration difficult or impossible. Excessive browsing by mammals will also damage trees and prevent regeneration. A growing concern is the increase in findings of new pests and diseases, which pose serious threats to Britain s woodlands. These include, amongst others, Chalara fraxinea (ash dieback), a fungal disease of common ash, Dothistroma needle blight which causes mortality in pine trees including Scots Pine, several Phytophtora species which have been spreading affecting a range of tree species. These pathogens may result in significant losses to tree species and could have a large impact on Scotland s woodland heritage. Diseases, pests and vegetation management in forestry are not covered in this Handbook, as the Forestry Commission and Forest Research already provide a range of information and guidance, on both specific issues and integrated management. Sources of information include: Guidance on IPM in forestry Willoughby I et al (2004) Reducing pesticide use in forestry: a practice guide, Forestry Commission/Forest Research, Edinburgh. Practice guide on managing and controlling invasive rhododendron Edwards, C. (2006). Managing and controlling invasive rhododendron. Forestry Commission Practice Guide. Forestry Commission, Edinburgh. Integrated Pest Management in Nature Conservation 112