Strategies for Control Based on Life Cycle of Invasive Plants

Transcription

1 Strategies for Control Based on Life Cycle of Invasive Plants Courtney LeClair Invasive Plant Specialist Wisconsin DNR

2 Weed Increase Over Time and Control Potential (1) (2) (3) (4) Prevention or Eradication simple Eradication feasible Eradication unlikely, intense effort required Local control and management only Public awareness typically begins Acres Infested Introduction Detection Control Costs Absent or off-site Few locations Many locations At or near biological potential Time

3 By the time you are in the control with a management strategy, the cost can be large and the failure rate is often high. Kudzu (Pueraria montana var. lobata)

4 Hill Mustard 2005.and 2009 Prevention is ALWAYS the best strategy! Early detection is critical for relatively efficient control

5 Plant Management Steps 1. Plant identification: What is it? Habitat sun vs. shade, wet vs. dry Life form herb, grass, vine, shrub, tree Life cycle annual, biennial, perennial Vulnerable points seedling, rosette, flowering, adult 2. Population size: How much? Select appropriate control tactic: What can I do? Monitor & adapt management over time: What can I do better?

6 What is the Goal of Management? Compliance with NR 40 Eradication of populations Improve cover of desirable species Improve ecosystem services land Prevention of invasion

7 Understand the biology of weeds How do they reproduce and spread? Annuals Biennials Simple Perennials Creeping Perennials Annuals Creeping Perennials

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10 Annuals and Biennials Plants grow from seed, produce seed once, and die. Population perpetuated by seed only. Seeds that can live for several years in the soil. Biennials overwinter as a rosette vulnerable stage for control. Goal - Prevent seed formation!

11 Garlic Mustard Alliaria petiolata Woodlands + shady roadsides

12 White (Melilotus alba) and Yellow (Melilotus officinalis) Sweet Clover Fields + sunny roadsides Photo: WDNR

13 Wild Parsnip Pastinaca sativa Photo: Photo: Fields + sunny roadsides Photo: WDNR WARNING: Phytophotodermatoxic

14 Teasels Common Teasel Dipsacus sylvestris Cut-leaved teasel Dipsacus lacinatus Fields + sunny roadsides

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16 Simple Perennials Perennials live to produce seed more than once. May resprout if cut back. Simple perennials do not spread extensively by making new shoots from roots, rhizomes, or runners Goal - Prevent seed formation + kill plants (if possible)

17 Purple Loosestrife Lythrum salicaria Wetlands + ditches

18 Spotted knapweed Centaurea maculosa Miketyler Jr. K.Holmes-GLIFWC

19 Dame s Rocket Hesperis matronalis Woodlands, grasslands, roadsides

20 Creeping or Spreading Perennials In general, more problematic than simple perennials Spread and reproduce extensively from seed and by making new shoots from roots, rhizomes, or runners Root fragments can start new plants Goal - Prevent seed formation + kill roots (if possible)

21 Canada Thistle Cirsium arvense Photo: Colorado State University Extension Photo: WDNR Photo: Colorado State University Extension Fields + sunny roadsides Photo: Colorado State University Extension

22 Productivity of an unmanaged invasive plant Canada thistle (creeping perennial) 1 root fragment planted in a soil box and let grow for a little over one year Richard Zollinger, North Dakota State University

23 Shoot and root growth next year 644 ft of roots and 336 ft of shoots Phil Westra, Colorado State University

24 Photo: WDNR Leafy Spurge Euphorbia esula Fields + sunny roadsides Photo: WDNR Photo: WDNR

25 Japanese Knotweed Polygonum cuspidatum Sun and shade, wet to dry Problematic on shorelines

26 Grasses Two of our worst are very large and dominant perennial grasses. Very high growth rates Form very dense sods that exclude all other species over time Can spread by seed, but mostly by roots and many buds at plant base Goal - Prevent seed formation, weaken tops by repeated mowing + kill roots through repeated efforts

27 Reed Canary Grass Phalaris arundinacea Fields + sunny roadsides Photo: WDNR Photo: WDNR

28 Common Reed Grass Phragmites australis Wetlands, shores, ditches

29 Invasive Shrubs Prolific fruits dispersed by birds Leaf out early and hold their leaves late Especially invaders of woodlands Many form thickets Most resprout if cut, unless stump-treated Goal Minimize seed formation, + remove tops and kill roots

30 Common Buckthorn Rhamnus cathartica Glossy Buckthorn Rhamnus frangula Free Picasa photo Photo: Chicago Botanic Gardens Forests, edges, backslopes

31 Eurasian bush honeysuckles Lonicera tatarica, morrowii, x bella Photo: Richard Old, XID Services, Inc. Bugwood.org Photo: WDNR Forests, edges, backslopes Kennith J. Sytsma

32 Autumn Olive Elaeagnus umbellata Forests, edges, backslopes

33 Invasive Vines Most are spread widely by birds that eat their prolific fruits. Grow along ground or climb trees, fenceposts, etc. Most resprout if cut, unless stump-treated Difficult to mow Goal Remove tops and kill roots

34 Oriental bittersweet Celastrus orbiculatus Forests, edges, fencelines TNC TNC

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36 Manipulation of the environment Competition/prevention in establishment Desirable plants compete with weeds Established plants are better competitors Limit disturbance Most weed species need disturbance to establish Prescribed burn Promotes some competitive species If timed properly, can kill young plants/seedlings

37 Mowing Can effectively reduce seed production Specific to weed species Annuals + Biennials Reduce population sizes if timed correctly and conducted for several years Perennials Typically need additional management to reduce populations

38 Herbicide Broadcast applications Pre-emergent emergent Post-emergent Directed methods Spot treatment Basal bark application Cut stump Wick Timing specific Nonselective herbicide Will injure any plant it contacts Selective herbicide Won t t harm grasses Won t t harm broadleafs Random selectivity Persistence No residual (hours -11 day) Short residual (days - week) Long lasting (months - year)

39 Prevention Wash equipment to remove soil and plant parts after used in an infested area Use weed free materials Hay and straw Gravel, fill, top soil Compost Keep adjacent areas weed free

40 Cleaning suggestions Remove plant parts, seeds, and dirt that may contain invasive species from anything transported off an infested site Also includes gear, clothing, and animals Tools to clean with Pressure washer Pressurized air Brush Washing stations