Invasive Alien Plants on Gabriola Island and throughout BC s South

Transcription

1 Invasive Alien Plants on Gabriola Island and throughout BC s South Coast Presented by: Pamela Wesley Extension & Outreach Coordinator Coastal Invasive Plant Committee February 4, 2009

2 Outline 1. Introduction to the Coastal Invasive Plant Committee (CIPC) Who we are, where we are, and what we do 2. Introduction to invasive plants What they are, why they re a problem, and how they spread, stages of invasion 3. Principles of Invasive Plant Management Prioritize, plan, minimize disturbance, re-vegetate, monitor, dispose of the biomass, ask for help, be careful, and don t give up.

3 Outline 4. Priority invasive plants on Gabriola Island Origin, characteristic, invasion details, management options 5. Other priority invasive plants in South Coastal BC 6. Resources

4 Coastal Invasive Plant Committee WHO are we? Registered non-profit society Mandate: Educate land managers & communities about invasive plants and their impacts Promote integrated vegetation management and cross-jurisdictional coordination Support land managers with invasive plant management programs

5 Coastal Invasive Plant Committee WHERE are we? Vancouver Island Gulf Islands Mainland regional districts of: Powell River Strathcona Mount Waddington 8 Regional Districts, 32 Municipalities & 57 First Nations

6 Coastal Invasive Plant Committee WHAT do we do? Annual General Meeting & Forum distribution list Website: Weed Hotline: (250) 857-CIPC Display booth Presentations and workshops Inventory, mapping and removal Educational materials Press releases and other media coverage

7 Invasive Plants

8 Invasive Plants WHAT are invasive plants? Non-Native (Alien) No natural predators Aggressive Characteristics Rapid growth High seed production and seeds that easily spread Resilience to poor conditions Multiple Reproductive Means Seeds Vegetative: Stolons (runners), Rhizomes, Cuttings, etc.

9 Invasive Plants WHY are they a problem? ENVIRONMENT Invasive species are the 2nd largest threat to biodiversity worldwide - IUCN Town of High River Reduce available wildlife habitat Displace native & desirable plants Introduce exotic pests & disease Reduce air, soil & water quality Increased wildfire hazard & severity and more.

10 Invasive Plants ECONOMY Reduced crop yield and quality Loss of livestock due to toxicity Poor forest regeneration following harvest Loss in property values due to reduced aesthetics, productivity & diversity Loss in recreational value or access Contamination of commercial trade products Invasive plant control can be very costly

11 Invasive Plants HUMAN HEALTH & WELLNESS Poisonings and related effects (i.e. liver damage), allergies, respiratory ailments, photosensitivy Loss of cultural/historical values Reduced access to recreational areas Reduced water & air quality Increased wildfire hazard Reduced visibility along transportation corridors Damaged infrastructure (e.g. rail lines, sidewalks, bridges) and more. USDA APHIS PPQ Archive King County Weed Control Board, WA

12 Pathways of Invasion HOW do invasive plants spread? Transportation & utility corridors Vehicles and maintenance equipment Agricultural crops Seed mix contaminants Parks & protected areas Recreationists, pets, sporting equipment, etc. Nurseries & landscaping By: jdj150 Waterways & wharfs Hitch a ride on boats, fishing equipment, etc.

13 Stages of Invasion Eradication Phase I m too busy with other problems Point of Detection Let s get to work! Management Cost

14 Principles of Invasive Plant Management

15 Principles of Invasive Plant Management Conduct an inventory and map the area Before you can develop an effective plan of attack, you must know: What invasive species area present; How abundant they are; Where your natural/cultural values are; Etc.

16 Principles of Invasive Plant Management Pick your battles a) Prioritize by species Highest potential to impact: native ecosystems, people s health, the appeal of the park/trail, etc. Greatest potential to spread Newest on the scene Regulated under BC s Weed Control Act versus

17 Principles of Invasive Plant Management Pick your battles b) Prioritize by site More significant natural values, etc. Highest potential to help spread the IP s Least invaded thus far vs. vs. CRD Parks CRD Parks

18 Principles of Invasive Plant Management Develop a Plan Start with satellite or stray individuals, and work towards more densely invaded areas (i.e. contain the invasion).

19 Principles of Invasive Plant Management Develop a Plan Buy yourself some time manage reproductively mature plants first. Spurge laurel / Daphne (Daphne laureola)

20 Principles of Invasive Plant Management Develop a Plan Select your removal/control method(s): Ecological approach know the strengths & weaknesses of the target species. What have others done? What worked? Which methods minimize impacts to native species and ecosystems? Which options work within your budget and operational constraints? Don t be afraid to try something new. Timing is critical!

21 Principles of Invasive Plant Management Rules of Thumb Annual herbs/forbs: Cut/mow the plants prior to flowering or seed set. Repeat as often as necessary until the seedbank has been depleted. Virginia Tech Weed ID Guide

22 Principles of Invasive Plant Management Rules of Thumb Perennial herbs/forbs: Pull up or dig up the plants and all underground roots prior to flowering or seed set. Repeat as often as necessary until: the seedbank has been depleted; and plants no longer sprout from any residual root fragments BC MAL

23 Principles of Invasive Plant Management Rules of Thumb Shrubs: Cut the plants below the root crown using clippers/loppers (late spring/summer). Pluck young plants, with stems <1.5 cm diameter (wet season). Repeat as often as required until the seedbank has been depleted.

24 Principles of Invasive Plant Management Rules of Thumb Sun-loving plants: After removing the plants in an appropriate manner, consider the following options Re-plant the area with trees or shrubs to create shade; Do not mow the area; allow desirable herbs to grow tall and create shade; or Heavily mulch the area, depriving it of access to sunlight

25 Principles of Invasive Plant Management Minimize soil disturbance Disturbed soil is prime habitat for many invasive plants. After removing the invasive plants, consider sowing native seed or replanting the site Bare/exposed soil is prime habitat for many invasive plants. Desirable plants can shade out invasive plants and compete with them for resources.

26 Principles of Invasive Plant Management Don t bite off more than you can chew Maintenance can be more time-consuming than the initial removal. If plants are permitted to set seed, efforts will have been wasted. Monitor the site on a regular basis

27 Principles of Invasive Plant Management Biomass disposal Composting is rarely recommended many invasive plants will re-grow from compost even hot compost. Many toxins will survive the composting process. However some plants (e.g. Vinca) may be composted after being thoroughly baked/dried in the sun. Some plants may be burned or incinerated; some are unsafe to burn out in the open. Some plants can be buried (land-filled) on site. Some plants must be sent to the land-fill.

28 Principles of Invasive Plant Management Ask for help/advice Contact the CIPC or other invasive plant experts for advice and for the latest information on invasive plants and control methods.

29 Be careful! Principles of Invasive Plant Management Many invasive plants pose threats to human health: Examples: Giant Hogweed, Knapweeds, Scotch Broom, Yellow Flag Iris, Daphne, Tansy Ragwort, etc. Know whether the plant species you are managing, poses a threat to your health, and know how to protect yourself.

30 Don t give up! Principles of Invasive Plant Management Invasive plants usually exhibit: Rapid growth; Resilience to poor conditions (e.g. drought, lack of sunlight); High seed production; High seed mobility; Long-lived seedbanks; and/or Vegetative reproduction: stolons, rhizomes, cuttings, etc. It is rarely ever easy to get rid of them!

31 Priority Invasive Plants on Gabriola Island

32 Invasive Plants on Gabriola Island Image pasted from the BC Ministry of Forests and Range s online IAPP application. This map is incomplete; as one zooms in closer, additional sites will appear. In addition, Gabriola Island has not been exhaustively surveyed to date. To access the interactive map online, visit the IAPP application website at:

33 Invasive Plants on Gabriola Island * = CIPC Priority Species Invasive Species # of Sites Comments BP Broad-leaved Plantain ~ 5 Drumbeg P.P., Sandwell P.P. BT Bull Thistle > 50 CD Curled Dock 2 Drumbeg P.P., Gabriola Sands P.P. CT Canada Thistle* >100 FB Field Bindweed 1 (a.k.a. Morning Glory) Sandwell P.P. GH Giant Hogweed* ~ 5 Orlebar Pt., South Rd., Martin Sir William, in and NE of Drumbeg P.P. GS Gorse* 1 Sandwell P.P. HE Henbit 1 Bertha at Suzanne (?) HI Himalayan Blackberry > 125 JK Japanese Knotweed* 2 Gabriola Sands P.P., Cooper at South Rd.(?) by Degnen Bay OD Oxeye Daisy > 10 PI Pineappleweed 2 Drumbeg P.P., Gabriola Sands P.P. SB Scotch Broom* > 150 Some major infestations. SH Scentless Chamomile 2 Horseshoe Rd., Bell s Landing SO Sowthistle ~ 5 Gabriola Sands & Sandwell P.P., Degnen Bay, Stalker Rd., Whalebone Dr.(?) TC Common Tansy* ~ 10 TR Tansy Ragwort* ~ 10 Some major infestations. YI Yellow Flag Iris* < 10 Descanso Bay & Valley, South Rd., Fenwick (?), Windecker

34 Scotch Broom (Cytisus scoparius) FRPA Origin: Europe Introduced as an ornamental Characteristics: Many invasions reported on Gabriola Isld. Perennial woody shrub, up to 3 m in height, with 5-angled stems Flowers: yellow (possibly with some red), pea-like, occur along the stems Leaves: lower leaves stalked and comprised of 3 leaflets; upper leaves un-stalked and simple

35 FRPA Scotch Broom (Cytisus scoparius) Infests: Exposed, well-drained soil in open, sunny areas Allelopathic compound impedes the growth of other plants Increases wildfire hazard and severity; obstructs sight-lines on roads Reproduction: Seeds: <35,000/yr, viable for decades (<80yrs) Management: Biocontrol 2 weevils Manual/mechanical cut large plants below ground level before flowering; hand-pull plants with stems <1.5 cm in diameter Many invasions reported on Gabriola Isld.

36 English Ivy (Hedera helix) Origin: Europe Introduced as an ornamental Present, but no invasions reported on Gabriola Isld. Characteristics: Ground-covering and climbing vine Flowers: white Fruite: white berries/drupes Leaves: characteristic (see display)

37 English Ivy (Hedera helix) Infests: Full sun to full shade Climbs trees and renders them top-heavy and susceptible to windthrow Deprives trees from access to air and important micro-organisms Reproduction: Seeds and vegetatively: roots sprout from ground-covering vines Management: Biocontrol none Manual/mechanical: Tree-climbing cut 1m segment out of vines at waist height, allow to die and remove from the tree. Ground-covering pull up all plant material and as much of the root network as possible. Present, but no invasions reported on Gabriola Isld.

38 English Holly (Ilex aquifolium) Origin: Europe Introduced as an ornamental Characteristics: Tree/shrub Fruit: red berries Leaves: green, glossy, sharp/spiny margins (variable) Present, but no invasions reported on Gabriola Isld.

39 English Holly (Ilex aquifolium) Infests: Full sun to full shade Can form dense stands and compete with other trees for sunlight and nutrients Reproduction: Seeds and vegetatively: will sucker from root system and will occasionally sprout new roots where branches make contact with the ground Management: Biocontrol none Manual/mechanical dig up or cut below root crown prior to seed set Present, but no invasions reported on Gabriola Isld.

40 Bull Thistle (Cirsium vulgare) FRPA Origin: Eurasia Many invasions reported on Gabriola Isld. Likely introduced as crop seed contaminant Characteristics: Biennial herb, up to 2 m in height, with fleshy taproot Flowers: purple, clustered, spiny seedheads Leaves: spiny, alternate, lance-shaped, clasping; basal rosette woolly and greyish 1 st year basal rosette; 2 nd year flowering stem

41 Bull Thistle (Cirsium arvense) FRPA Infests: Open, sunny, waste areas Many invasions reported on Gabriola Isld. Generally does not pose a threat to high quality areas; does not withstand cultivation Unpalatable to wildlife and livestock Reproduction: Seeds: <4,000/yr, viable for >10 yrs, dispersed by wind Management: Biocontrol 3 weevils and 1 fly Manual/mechanical cut plants below the root crown annually until the seedbank is depleted

42 Canada Thistle (Cirsium arvense) FRPA, WCA Origin: Eurasia Many invasions reported on Gabriola Isld. Likely introduced as crop seed contaminant Characteristics: Perennial forb, up to 2 m in height Flowers: purple, clustered, smell like vanilla ( ) Leaves: spiny, alternate, lance-shaped, clasping BC MAL Spring growth in the form of rosettes of spiny, wavy leaves

43 Canada Thistle (Cirsium arvense) FRPA, WCA Infests: Open, sunny areas Many invasions reported on Gabriola Isld. Reproduction: Seeds: ~1,500/yr, viable for <3 yrs, dispersed by wind Rhizomes (roots): spread up to 2 m/yr Management: BC MAL Biocontrol none Manual/mechanical repeatedly pull plants/roots; repeated mowing before flowering to reduce seed set

44 FRPA, WCA Common Tansy (Tanacetum vulgare) Origin: Europe Introduced as an ornamental and medicinal herb ~10 invasions reported on Gabriola Isld. Characteristics: Perennial forb, up to 1.5 m in height Flowers: yellow, button-like, form flat-topped clusters at the top of the plant, appear in late summer Leaves: alternate, deeply divided By: CarlELewis

45 FRPA, WCA Common Tansy (Tanacetum vulgare) Infests: Open, sunny areas & riparian areas Undesirable forage May be toxic to livestock and humans ~10 invasions reported on Gabriola Isld. Reproduction: Seeds Rhizomes Management: Biocontrol none Manual/mechanical repeatedly pull plants/roots; repeated mowing before flowering to reduce seed set By: CarlELewis

46 Curled Dock (Rumex crispus) Origin: Eurasia Likely introduced as a crop seed contaminant ~2 invasions reported on Gabriola Isld. Characteristics: Perennial forb, up to 1.5 m in height, with fleshy taproot; becomes reddish brown with age Flowers: greenish or reddish in clusters <0.5 m long Leaves: lance-shaped, basal rosette and along stem

47 Curled Dock (Rumex crispus) Infests: Open, disturbed areas May be toxic to wildlife and livestock Can carry crop diseases Reproduction: Seeds: >60,000/yr; dispersed by wind, water, people, animals, equipment, etc.; seedbank long-lived Can re-sprout from underground root system Management: Biocontrol none Manual/mechanical hand-pulling, removing entire root system; cut below ground before flowering to prevent seed set. ~2 invasions reported on Gabriola Isld.

48 Field Bindweed (Convolvulus arvensis) a.k.a. Morning Glory Origin: Eurasia Introduced as an ornamental and crop seed contaminant Characteristics: ~1 invasion reported on Gabriola Isld. Rapid growing, deep rooted, long-lived, perennial ground cover Flowers: white to pink/purple; trumpet-shaped; up to 3 cm in length Leaves: arrowhead-shaped, <5 cm in length

49 Field Bindweed (Convolvulus arvensis) a.k.a. Morning Glory Infests: Open, sunny areas Competes with crops & native plants for resources and can choke them out Reproduction: Seeds: seeds viable in soil for >25 yrs Rhizomes: extensive, fast-growing, underground root/rhizome network Can re-sprout from plant fragments Management: Biocontrol 2 beetles and 1 mite Manual/mechanical repeated cultivation (every 2-3 wks for 2-3 yrs) can eliminate some invasions; black plastic mulch or fabric weed barrier to exclude light for up to 5 years ~1 invasion reported on Gabriola Isld.