Views About Management

Transcription

1 Views About Management A statement of English Nature s views about the management of Site of Special Scientific Interest (SSSI). This statement represents English Nature s views about the management of the SSSI for nature conservation. This statement sets out, in principle, our views on how the site s special conservation interest can be conserved and enhanced. English Nature has a duty to notify the owners and occupiers of the SSSI of its views about the management of the land. Not all of the management principles will be equally appropriate to all parts of the SSSI. Also, there may be other management activities, additional to our current views, which can be beneficial to the conservation and enhancement of the features of interest. The management views set out below do not constitute consent for any operation. English Nature s written consent is still required before carrying out any operation likely to damage the features of special interest (see your SSSI notification papers for a list of these operations). English Nature welcomes consultation with owners, occupiers and users of the SSSI to ensure that the management of this site conserves and enhances the features of interest, and to ensure that all necessary prior consents are obtained. Management Principles Blanket bogs Blanket bogs are a peatland habitat confined to cool, wet climates. Peat forms where certain plants decompose very slowly under waterlogged conditions. In ideal circumstances, the peat develops over large expanses of uplands, effectively blanketing them. The wet, nutrient-poor growth conditions provided by peat means that the bogs and their associated pools support unique communities of specialised plants and animals. They can also be important habitats for breeding populations of wading birds. In the South Pennines much of the blanket bog resource has been negatively affected by pollution from the Industrial Revolution and past burning, drainage and grazing management regimes. Whilst they still have great value for breeding birds, including waders, as well as other species, they do not usually support the full range of specialised plants and animals or the balance of plant species in the habitat s vegetation types that would normally be expected. Management will usually therefore need to focus on restoration but with the understanding that re-creation of an ecologically fully functioning bog habitat may not always be possible or may take a very long time. Many blanket bogs have traditionally been managed for livestock and/or for grouse shooting. Where this management has been intensive, damage may have occurred through overgrazing, burning and drainage as outlined above. However, the nutrientpoor and waterlogged conditions of blanket bogs that are not degraded and are in Page 1 of 10

2 favourable condition often means that very little management is actually needed and such sites should require little intervention. On some sites light grazing may be beneficial. This can be used to control the development of invasive vegetation on the blanket bog, especially on those sites that may have suffered from drainage and previous intensive management. However, care needs to be taken in deciding the precise timing and intensity of grazing. As a general rule, the wetter a site is, the greater the sensitivity to grazing. Light summer grazing by sheep is likely to be an acceptable regime. Heavy grazing must be avoided, as it may lead to an increase in the cover of grazing tolerant plants, such as purple moor-grass, and a consequent reduction in the extent of important moss and lichen species, and can also cause damage through trampling. Burning blanket bog can also reduce its conservation value by reducing the diversity of plant and animal species present on the bog, and should not be introduced on high quality blanket bog. On other types of blanket bog and deep peat habitats whether burning should be part of the management regime will need to be determined and reviewed/amended in light of experience on an area by area basis. Relevant considerations will include the site s conservation objectives, the likelihood of burning holding back the restoration of high quality blanket bog, the observed effects of any burning and the latest scientific understanding of the impacts. Any burning that is consented over peat soils on blanket bog (including degraded examples) must be very carefully undertaken to ensure that no (further) damage to the habitat and peat soils occurs. This in practice will mean all burns must be 'cool and quick' and not burn into any moss and litter layer or in the worst case scenario burn into the peat itself. In addition sensitive areas, such as those that contain pools, should not be burnt, as it can be very damaging to the invertebrate and amphibian populations that they support. Fire can also damage the peat soils themselves and can prevent the formation of new peat. This can result in peat erosion and the loss of peat by wind or water. In areas where the risk of accidental fires is high, firebreaks can be cut, providing care is taken when using the necessary machinery to avoid damage to the underlying peat. No new drainage should be introduced to blanket bogs and deepening of any existing drains or grips should be avoided. It is likely to be necessary to block existing drains to prevent further drying out of the bog and damage to peat soils. On sites that have been degraded, it may be necessary to undertake further restoration works. It is also important to protect peat and peat-forming systems, as they can hold a significant store of carbon. Wet and dry upland heath Dry upland heath develops in nutrient-poor, acidic conditions in unenclosed upland areas and is dominated by dwarf shrubs, especially heather. Wet upland heath occurs in areas where peat accumulation results in damp, nutrient poor soils, which allows the characteristic plants of wet heathland, such as heather and cross-leaved heath, to dominate the vegetation. Upland heaths are unique plant communities that support a rich variety of plants and animals, including many rare and scarce species of plants, birds and invertebrates. Dry upland heaths have a long history of active management. Continued habitat management is essential for maintaining the nature conservation interest and open Page 2 of 10

3 nature of dry upland heaths by preventing the invasion of scrub and trees that would otherwise dominate these dwarf shrub communities. Management of upland dry heath should aim to create a structurally diverse mosaic of dwarf shrub vegetation to provide the feeding, breeding and sheltering areas needed by the range of plants and animals that are characteristic of a well managed upland. For example, structural diversity can be particularly important to the conservation of invertebrate species, which are also an important food source for other animal and bird species. It is generally beneficial if all phases of the heather life cycle are present. Light grazing, particularly in the summer months, is a suitable means of managing dry heath. By feeding selectively on different plants and in different areas, stock can ensure that patches of young, open vegetation growth are found in mosaics with more mature and even degenerate areas of heather. Grazing can be beneficial in more subtle ways, too. For example, dung is an important habitat for certain invertebrates that in turn provide food for birds. However, grazing must be carefully controlled. Stock levels need to be appropriate to the type and age structure of the vegetation. Heavy grazing can lead to the loss of dwarf shrub cover and a consequent shift to grass and rush communities, which reduce the structural diversity necessary for maintaining a variety of upland animal and plant species. Excessive trampling and poaching by livestock can damage the habitat further. Stock levels should be light, preferably with no or little winter grazing. Increasing altitude and wetness reduces the ability of moorland vegetation to cope with grazing pressure. High deer numbers can also have a significant effect on vegetation and should be taken into account when deciding stocking rates. The impoverished conditions of areas of undisturbed wet heaths mean that usually very little management is needed to maintain them, and such areas should be left completely alone as far as possible, although some management may be necessary to prevent the invasion of shrubs and trees and maintain the structural diversity of the vegetation. This should be no more than very light summer grazing, with stock removed during the autumn and winter. Heavy grazing can lead to a decline in characteristic dwarf shrub cover in favour of grass and sedge species and should be avoided. Heavy grazing can also lead to excessive poaching and erosion of the peat. High deer numbers can have a significant effect on vegetation and should be taken into account when deciding stocking rates. Careful periodic burning may be a useful tool for maintaining structurally diverse dry heath, but burning should not normally be introduced to areas that have not been burned before. Burning must be used with caution, as inappropriate burning can be very damaging to both plant and animal communities. Burning should only be undertaken during the winter and should follow an appropriate burning rotation in order to create a mosaic of habitats with vegetation of different ages, composition and structure, which in turn supports a wide diversity of species. For example, burning small patches on a long rotation creates a diverse structure and reduces the impact on animal populations invertebrates in particular, are vulnerable to the effects of fire. The use of burning as a management tool on wet heath can be damaging to the sensitive plant communities of wet upland heath and should be avoided. Cutting is a possible alternative to burning on dry heath. If cutting is used, care must be taken to remove the resultant litter, or germination of seedlings will be inhibited. Cutting can be usefully employed to create firebreaks. However, care must be taken Page 3 of 10

4 when using the machinery required for cutting as this can be damaging to fragile peat soils, in particular those of wet heaths and the use of machinery should be avoided where possible on wetter areas. Any artificial drainage is damaging to wet heath plant and animal communities and should be avoided. Drainage can have a number of damaging effects on both the wet heath and the surrounding environment through, for example, lowering of the water table, increased erosion of peat, siltation of streams and rivers and increased risk of flooding. Occasional management of invasive bracken may be necessary on some sites though bracken in the right places can be a valuable part of an upland habitat mosaic. Upland acid grassland Upland acid grasslands develop on nutrient-poor, acidic soils and are a natural component of the uplands, although acid grasslands are also sometimes the result of heavy grazing and over burning on dwarf shrub and blanket bog communities. When found in a mosaic with other habitats, such as dwarf shrub heath and mire communities, acid grasslands can be an important addition to the diversity, structure and function of the upland landscape. Where the objective of management is to retain acid grassland as part of the upland mosaic active management is required. If neglected, the build up of dead plant material may suppress less vigorous species and reduce the botanical richness of the site. Traditionally, acid grasslands are managed by grazing at appropriate stocking rates and can support stock throughout the year. However, the precise timing and intensity of grazing will depend on local conditions and requirements, such as the need to avoid trampling ground-nesting birds. Some consideration should also be given to the nature of past grazing management on the site, which may have influenced the species present in the sward today. On other upland acid grasslands the objective of management may be to restore the dwarf shrub vegetation characteristic of upland heath and/or blanket bog. Where this is the case, a reduction in grazing pressure is likely to be required. Indeed, it may be necessary to remove grazing altogether for an initial period and it will usually be appropriate to avoid winter grazing in the long-term. The ability of dwarf shrub heath to recover depends on a number of factors, particularly whether or not heather and other dwarf shrubs are present, and at what level. If there is some heather present, then grazing should be removed from these areas first. The soil under heather contains a large seedbank that can remain viable for several years, so light disturbance of the topsoil may be a useful technique for restoring areas that have only recently converted to grassland. Different types of upland heath may require different management techniques to restore them, for example, to recreate wet heath, water levels may need to be raised. Occasional management of invasive scrub and bracken may be necessary on some sites though both scrub and bracken in the right places can be a valuable part of an upland habitat mosaic. Page 4 of 10

5 Marshy grassland Marshy grassland requires active management if it is to retain its conservation interest. Generally, each year s growth of vegetation must be removed. Otherwise the sward becomes dominated by tall, vigorous grasses and rushes which, together with an associated build up of dead plant matter, suppress less vigorous species and lower the botanical richness of the sward. Traditionally, this management is achieved by grazing. Cattle are often the preferred stock, being relatively tolerant of wet conditions and able to control tall grasses and rank vegetation. Cattle also tend to produce a rather uneven, structurally diverse sward. However, ponies, or even hill sheep, can be used if necessary. Grazing usually takes place at times between late spring and early autumn, but the precise timing and intensity will depend on local conditions and requirements, such as the need to avoid trampling ground-nesting birds. Heavy poaching should be avoided but light trampling can be beneficial in breaking down leaf litter and providing areas for seed germination. An element of managed scrub, both within and fringing a field can be of importance to birds and invertebrates, as can a surrounding hedge. Careful maintenance of existing ditches and drains is usually acceptable practice, but abandonment or deepening of ditches can be harmful. Neutral hay meadow and neutral pasture Neutral hay meadows and neutral pasture require active management if they are to retain their conservation interest. In order to maintain a species-rich sward, each year s growth of vegetation must be removed. Otherwise the sward becomes progressively dominated by tall and vigorous grasses which, together with an associated build up of dead plant matter, suppress less vigorous species and reduce the botanical diversity of the site. In neutral hay meadows, the above objective is traditionally achieved by closing the fields to stock in the autumn and cutting the resultant growth as hay. The cut is usually done in early July, but the precise timing depends on local factors, including past management and current weather conditions. It should always be after groundnesting birds have fledged their young and any short-lived, characteristic plants have set seed. The aftermath is then grazed in late summer/autumn. Aftermath grazing is important for maintaining a species-rich sward, both through controlling competitive grasses and through hoof-prints providing suitable sites for seedlings to establish. Heavy poaching must be avoided, however. On pasture land this management is achieved by grazing. The precise timing and intensity of grazing will vary both between and within sites, according to local conditions and requirements (such as the type or availability of stock, or the needs of individual plants or animals of conservation concern) but should aim to keep a relatively open sward without causing excessive poaching. Light trampling can be of benefit by breaking down leaf litter and providing areas for seed germination. Any surrounding, well-managed hedgerows may considerably add to the habitat in providing shelter for invertebrates. Occasional dressings of lime may be acceptable. For damper pastures, regular and careful maintenance of surface drainage including ditches and drains can be essential to prevent adverse changes in the plant species composition of the sward. Deepening of surface drainage should be avoided. Periodic Page 5 of 10

6 dressings of well-rotted farmyard manure may be acceptable if the sward does not receive regular input of nutrients from flooding. Flush and spring fen Groundwater sometimes breaks out on the surface, either as gentle seepages, which give rise to flushes, or through greater flows that are evident as springs. The plants and animals that occur in and around these habitats are dependent on the water chemistry and flow rate. Mosses, liverworts, sedges and rushes are common and often predominate, whilst several species of orchid are also associated with these communities. The quantity and quality of the groundwater must be maintained, though the quantity is not likely to be naturally constant throughout the seasons or between wet and dry years. Groundwater is often susceptible to contamination by agricultural fertilisers, or by pollution leaking from landfill sites Grazing is often required to keep the vegetation short and open around springs and flushes. The precise timing and intensity of grazing will vary according to local conditions and requirements but should aim to keep a relatively open sward without causing excessive poaching. Feeding of stock should take place well away from the springs (and any other sensitive habitat), and the location of structures such as animal shelters should not encourage the animals to gather in the area. This is to ensure the springs and flushes do not become enriched by nutrients from animal food or dung, or even from carcases. Light trampling by grazing animals can be of benefit in moderation by breaking down leaf litter and by creating areas of bare soil, needed by some invertebrates and mosses and for seedling establishment. Drainage schemes should not intercept the source of groundwater to springs or flushes, or reduce the area of surface they irrigate. Valley mire Fen often develops within valleys and the origins and movement of the water within the fen give rise to a number of different vegetation zones. The variety of plant and animal life in the valley mire is closely linked to the number and type of zones it contains. Management should aim to maintain the groundwater quality and quantity, though the quantity is not likely to be naturally constant throughout the seasons or between wet and dry years. The groundwater is often susceptible to contamination by agricultural fertilisers, or by pollution leaking from landfill sites. Grazing is important in the management of the valley mire. Animals help to break up the tussocks of rank grasses such as purple moor grass, opening the sward up to a greater variety of plants. The precise timing and intensity of grazing will vary according to local conditions and requirements. Some (but not excessive) trampling is necessary to create open soil, for invertebrates, mosses and seedling establishment. Grazing also limits the spread of willow, alder and birch carr, which naturally tends to develop around the central watercourse and it should be restricted to this area, other than for a few isolated clumps elsewhere for the benefit of birds and invertebrates. Page 6 of 10

7 Swamps are also important for invertebrates and birds and the inclusion of some swamp vegetation, such as reedbed, within the mosaic of habitats present will add to the conservation value of the site. However, excessive spread of reed, reed canary grass, or reed sweet grass is likely to be an indication of worsening water quality, the cause of which should be investigated and addressed to maintain the characteristic fen communities. Stock feeding, or the location of grazing infrastructure, for example stock shelters, should take place downstream of the valley mire. This is to ensure the mire vegetation does not become enriched by nutrients from animal food or dung, or even from carcases, causing unwanted changes in the composition of the characteristic mire vegetation in favour of tall, species-poor communities. Drainage schemes should not intercept the sources of ground and surface water to the valley mire. It is important for the watercourses of the valley mire not to receive runoff from fertilised land or surface water from farmyards. The bed of the watercourse should not be lowered, nor should its water level be artificially raised, other than as part of a well thought-out conservation scheme. This will ensure the various vegetation components of the valley mire are maintained in their ideal proportions, and that head-ward erosion is not triggered, in which increased flow gradually erodes the peat and silt on which the valley mire has developed. Upland semi-natural woodland Past and present management, high rainfall and relatively clean air are all factors which have helped make upland woods home to a wide range of species and plant communities which are scarce or absent in lowland woodland. Upland woods may be home to a number of rare flowering plants and are often rich in mosses, liverworts and lichens. They can have a very distinctive bird fauna, including species such as redstart and pied flycatcher, and are also valuable habitats for invertebrates and mammals. Most upland woods were once managed as coppice, being cut on regular rotations for the oak bark and charcoal industries. However, most of this coppicing stopped in the nineteenth century. As a result the woods developed more importance as shelter for domestic stock and much upland woodland is now grazed high forest. This, combined with increasing levels of grazing by deer, means that most upland woods are likely to benefit from some reduction in grazing pressure to allow the ground flora and shrub layer to recover. Grazing may need to be removed altogether from some woods, at least in the short term, to allow the natural regeneration of tree species. Temporary fencing, or the maintenance of walls around woods, may be suitable methods of stock control. That said, it should be remembered that grazing has helped to develop the valued features of some upland woods. For example, some grazing appears to benefit characteristic woodland birds like pied flycatcher, and it also helps to maintain the light, open conditions that can benefit some moss and lichen communities. Careful thought needs to be given to the benefits of excluding stock, from which parts of the wood and for how long. Page 7 of 10

8 In some woods it may be appropriate to re-introduce coppicing, for example if a wood has very good butterfly populations that would benefit from an increase in more open, light conditions. However, re-introducing coppicing will certainly not be suitable for all woodlands. In most cases the retention of high forest, with its more complex structure and rich moss and lichen communities, will be the best form of management. Further intervention may be required to combat the effects of invasive non-native plants. Rhododendron, in particular, is a major threat to many upland oakwoods, smothering the ground flora and inhibiting the natural regeneration of tree species. It should be removed wherever practical. In other cases, all or part of a wood can be left to develop naturally without any active management. For example, wet woodland - which tends to be dominated by species such as alder, willow and birch - is a scarce habitat in the uplands and is likely to benefit from minimum intervention. Dead wood, both fallen and standing, can be of considerable value to wildlife, particularly fungi and invertebrates and should be retained where present, providing that it is safe to do so. Dead wood tends to be a scarce habitat in the uplands because so many upland woods have been managed as coppice in the past. Often, upland woodland will lie next to moorland habitats which may be managed by burning. Burning is entirely inappropriate for the management of woods and fires on adjacent land should not be allowed to run into them. As a general rule, those woods that have been under-planted with conifers should be restored. Where appropriate, native woodland should be allowed to naturally expand, although it is important that this is not at the expense of other upland habitat which has its own nature conservation importance. Inland outcrops and stream sections The ideal management for natural inland geological sites is the maintenance of rock exposure free of vegetation and, in some cases, the build-up of rock debris. Management usually involves periodic clearance of vegetation and rock debris. Vegetation growth is a problem on many sites, because erosion rates are usually too low to naturally maintain fresh exposure of the geological features. It may not be always practical or entirely necessary to maintain full exposure of the geological features on a site. Site management will often involve defining specific areas that need to be kept clear of vegetation and rock debris. Collecting of geological specimens may be acceptable if undertaken in a responsible manner. However, there are some sites where the geological interest is very finite in nature and over-collecting can result in damage or destruction of the interest. Collecting of specimens requires very careful management to ensure that the geological resource is conserved. The main threats to conservation of inland geological sites are developments that obscure the rock exposures. Tree planting can also conceal rock exposures. Page 8 of 10

9 Upland bird assemblages The English uplands support a highly distinctive breeding bird community with many species of international importance. The diverse variety of upland habitats should be managed in order to safeguard their populations. There is evidence that the densities of some species of ground nesting bird differ between grouse moors and similar areas not managed for grouse, suggesting that moorland management benefits some species whilst disadvantaging others. It is not clear whether these differences are due to habitat differences or management (rotational burning) or to the control of species like crow, fox and stoat. Structural diversity of vegetation is important and thus sympathetic grazing and burning regimes are crucial. Areas of taller heather in places, such as on slopes or along watercourses, may provide suitable nest sites for Merlin, Hen Harrier, Shorteared Owl and Twite. Conversely, shorter vegetation (particularly on flatter, gently sloping land) provides nesting and feeding sites for birds such as Golden Plover and Curlew. Any burning above peat soils needs to be cool and quick, and should avoid damage to the moss layer and the peat surface. Grouse moor management also involves intensive predator control and in some locations this may result in increased numbers of certain species of ground nesting birds. For species with precariously low numbers, such as black grouse, this work may be undertaken alongside habitat improvements to maintain or build populations. Any disturbance to, or illegal persecution of birds of prey would clearly be damaging. Improvements of enclosed land should be avoided. The re-instatement of tussocky, uneven swards through appropriate stock grazing will provide nest sites and feeding areas for Snipe, Redshank, Lapwing and Curlew. Bracken control is desirable where seen to be invading habitats of importance. Some patches of bracken may be targeted for scrub or woodland regeneration. In places bracken can provide potential nest sites for birds like Twite, Ring Ouzel and Linnet. On both open moorland and enclosed farmland, it is vital to maintain or enhance soil wetness and wetland features such as pools and flushes, and to retain and develop local cover of native scrub, scattered trees and woodland. The blocking of grips across peat and blanket bog will enhance soil wetness. Upland riparian habitats can support important populations of Common Sandpiper, Grey Wagtail and Dipper, whilst Tufted Duck and Goosander also inhabit upland standing freshwaters. These habitats should have exceptionally high water quality, and appropriate levels and flow regimes. The natural channel of rivers should be retained or restored, as should the shore profile of standing waters. Surrounding swamps and fens should be retained or restored around standing waters, as should the native bank side vegetation of rivers. Species interest The vascular and lower plant flora and invertebrate fauna of the site is of special interest. The species are found in the above habitats and in general the management Page 9 of 10

10 described above will meet their needs. There may however be circumstances when specific management measures are needed to ensure the well-being of a species. In these situations the management will be discussed and agreed on a case by case basis. All habitats The habitats within this site are highly sensitive to inorganic fertilisers and pesticides, applications of which should be avoided both within the site itself and in adjacent surrounding areas. Herbicides may be useful in targeting certain invasive species, but should be used with extreme care. Access to this site, and any recreational activities within, may also need to be managed. Page 10 of 10