Download PRESENTATION NAME - Carleton College

Terrestrial Invasive Plant
Species
Habitat Workshop
2010
Carleton College
An introduction to the issues
and a few answers (it’s a big topic)
Nancy Braker
Arboretum Director – Carleton College
Definition
"Invasive species" by MN law, means a nonnative species that can naturalize and:
1) causes or may cause economic or
environmental harm or harm to
human health; or
2) threatens or may threaten natural
resources or the use of natural
resources in the state.
(M.S. 84D.01, Subd. 9a)
Definition
Species that have been introduced, or
moved, by human activities to a location
where they do not naturally occur and
cause ecological or economic problems
We live in a highly mobile world
Definition
Aggressive natives vs invasive species:
• Native species can also invade a site
• Ecological changes can cause native species to
dominate areas where historically they have not
Consequences of Invasive Species
™Ecology
™Recreation
™Economics
Ecological Consequences
• Changes in natural community structure and
composition
Ecological Consequences
• Changes in nutrients or chemical composition of
soils (allelopathic responses)
Ecological Consequences
• Changes in habitat for birds, amphibians,
invertebrates, etc.
Ecological Consequences
• Changes in biodiversity
Recreational Consequences
Scenic and aesthetic changes
Recreational Consequences
Hiking and hunting
Economic Consequences
• Damage and control
costs are estimated
at $138 billion each
year (USDA, 2000)
• In FY09 MDNR Parks spent
approximately $600,000 on
226 invasive species control
projects
• Average cost per acre
for invasive species control is
between $250 and $1500
depending on percent
slope and infestation
Economic Consequences
Lost Revenue
– Increased management cost
• Herbicide treatments
• Timber stand improvement cost
– Loss of timber production
• Invasive species may compete with desired
natives
– Loss of target species regeneration
• Need to plant and not rely on natural
regeneration
Types of Pathways
• Human activity
– Intentional (nursery stock)
– Non-intentional (ballasts, soil)
• Animal activity
– Feeding
– Travel pathways (garlic mustard)
• Abiotic activity
– Floods/Storms
– Wind
Pathways
Vehicles
Seeds or
vegetation
in grill
Mud in truck tires
Seeds or vegetation stuck in various
parts of vehicle
Pathways
Foot Traffic
Material brought to site
Pathways
Recreation
Horses, bikes,
pets, and you can
move species
from one habitat
to the next.
Pathways
Wildlife movement
Ingesting seed or
transporting plant
materials in their fur
or on their feet
Planning Your Attack
Survey and Map - Understand the
problem
• What invasive species do you have?
• What is the scope of the problem?
• Keep informed of and look for potential
new problem plants
Planning your Attack
Mapping
Simple to complex
• Hand drawn map
• Aerial photo with notes
• GPS
• Geographical Information
System (GIS)
Survey Example
Black Swallowwort
Planning your attack
Develop a plan
• What are your control options?
• Where do you start?
– Prioritize: small infestations may be more
important then largest
• What will you plant instead?
– How will you fill the space that you
just cleared out?
Planning your attack
Monitor
• How will you keep track of your
progress?
• Are you making progress?
• Do you need to try some other tactic?
Identification
A few of many!
Woody Plants
• Buckthorn
• Bush Honeysuckles
• Japanese Barberry
• Black Locust
• Amur Maple
• Siberian Elm
Herbaceous Plants
• Garlic Mustard
• Spotted Knapweed
• Wild Parsnip
• Reed Canary Grass
• Thistles
Identification
Buckthorn
• Native to Europe
• Single- or multistemmed up to 20 ft
• Forms canopies in
forest understory
• Impacts
– Shades native species
– Changes soil chemistry
– Reduces regeneration
of tree seedlings and
herbaceous layer
Common buckthorn
Rhamnus cathartica
Glossy buckthorn
Frangula alnus
Identification
Buckthorn
• Leaves sub-opposite
• Twigs tipped with sharp
thorn
• Buds pressed to stem
• Leaves with curved
parallel veins
• Berries black with
several seeds
Buckthorn
Can be confused with:
• Wild Cherry
• Wild Plum
• American Plum
• Grey Dogwood
• Red twigged dogwood
Cherry
Identification
Common Buckthorn
Glossy Buckthorn
• prefers dry soils
• open woods, savannas,
clearings, roadsides,
and disturbed areas,
also invades prairies
• prefers a wetter
environment than
Common Buckthorn
• Bogs, fens, sedge
wetlands, and disturbed
areas
Identification
Bush Honeysuckles
(Lonicera spp.)
– Native to Japan
– Multi-stemmed, deciduous
shrub
– Up to 15 ft tall
– Flowers in May or June
– Cause declines in native
plant species of woodland
and forest communities
Morrow’s
Tatarian
Bells
Bell’s
Identification
Morrow’s
Bush Honeysuckles
• Open woodlands,
abandoned fields, other
disturbed areas; also
invades forests, savannas
and prairies
• Prefers moister soils, but
can be found in drier
environments
Tatarian
Identification
Japanese Barberry
(Berberis thunbergii)
– Native to Japan
– Small deciduous shrub 3-5 ft tall
– Slightly curving branches with thin, straight
spines. Bright yellow inner bark
– Very small (0.5-1.5 in) green, blue-green,
or reddish-purple leaves
– Flowers in early May; bright red berries
– Forms dense stands that displace natives
Identification
Japanese Barberry
• Prefers well-drained
soils
• Oak savanna and oak
forest, but grows and
bears fruit in full sun to
full shade; wetlands upland forests
Identification
Black Locust
(Robinia pseudoacacia)
– Native to U.S. (Appalachian)
– Deciduous tree up to 75 feet tall
– Seed pods are 2-4 in long; flowers
are fragrant and grow in elongated
clusters
– Flowers in May and June
– Was commonly planted for erosion
control
– Alters nitrogen cycling and
competes with native plants
Identification
Black Locust
Invades woodlands,
savannas,
prairies, edge
habitats,
abandoned
fields, and
disturbed areas
Identification
Amur Maple (Acer ginnala)
– Native to Asia
– Small deciduous tree to 20 feet
– Twigs are smooth and light
– Turns bright red in fall
– Fragrant flower clusters in May and
June produce many seeds
– Forms dense stands that displace
native plants
– Planted as an ornamental
Identification
Amur Maple
• Grows best in moist, welldrained soils with full sun,
but tolerates a wide variety
of pH, soil, and shade
conditions
• Especially successful in
open woods and savannas
Identification
Siberian Elm (Ulmus pumila)
– Deciduous tree to 70 feet
– Silver-gray twigs have a zig-zag
shape with leaf bud at each turn
– Leaves base only slightly
uneven (compared to American
elm with asymmetrical base)
– Invades pastures, roadsides, and
prairies
Identification
Garlic Mustard (Alliaria petiolata)
– Native to Europe
– First recorded in 1933
(UM herbarium records)
– Biennial, herbaceous plant
– Flowers May-June (white)
– Causes declines in native plant
species of the forest understory
and bottom lands
Identification
Garlic mustard life stages
Infestation
Rosettes
Flowering Plants
Seed pods
Identification
Garlic mustard
• Prefers disturbed areas; wet, shaded,
deciduous woods, floodplain forests
• Also spreads to
upland forests and
other habitats
Identification
Spotted knapweed (Centaurea maculosa)
–
–
–
–
–
Native to Europe and Asia
Biennial or short-lived perennial
3-4 feet tall
Small pale leaves
Single thistle-like pinkish-purple
flower
– Tap root
– Inhabits dry to wet sandy soils
Identification
Wild Parsnip (Pastinaca sativa)
– Monocarpic perennial
– Rosette 6-12”, flowering
stage 4’ tall
– Alternate leaves with 5-15
leaflets on both sides of
common stalk
– Yellow flat-topped flower
(parsley-like)
– Flowers in June thru late
summer
Identification
Wild Parsnip
– Spreading widely
in MN – mowing
roadsides
distributes seeds
– May produce
severe rash
– Toxic response
depends on prior
damage to plant
Identification
Reed canary grass (Phalaris arundinacea)
– Planted for forage, silage, and fodder
– Invades wetland and floodplain communities, also
found in crop field waterways
– Perennial grass
– Reproduces from rhizomes
and seed
– 2 – 6 feet high
– Forms dense monocultures
Identification
• Thistles
– Musk thistle
• Biennial, 2-6’ tall
• Multi-branched stem with
nodding flowers
– Canada thistle
• Perennial, 2-4’ tall
• Stems branch at top only
• Fibrous taproot with
spreading horizontal roots
– Bull thistle
• Biennial, 3-6’ tall
• Alternate, coarsely lobed
leaves with spines at each
tip
Mechanical Control
•
•
•
•
•
Pulling
Cutting
Mowing
Grazing
Fire
Pulling
• Most species can be pulled
(works better for some)
• Soil disturbance may harm
native species or create
seed bed for invasives
• Take enough root with the pull
(usually root crown)
• Put plant in plastic bag
or burn on site (when seed can
germinate)
Grazing
• Can either promote or
reduce weed abundance
• Will not completely
eradicate invasive plants
• When combined with
biological control or
herbicides it may eliminate
the species
Fire
• Will sometimes promote
invasive vegetation
• Timing and intensity are
important
• Most effective before
flowering or seed set
• Often used to reduce
litter so herbicide will be
more effective
Mowing
• Can be somewhat
effective (most useful
with species that spread
through seed and not
vegetatively)
• Timing is important—before seed set is most
effective
• Like fire, may stimulate invasive species growth
Chemical control
• Type of chemical depends on the target species
• Always follow directions & wear safety equipment
• Broadcast, cut stump, or
basal bark treatments
• Research and
know which is most
effective, how it
works, and how to use it
Biological Control
• Available for some species;
research underway for others
• Goes through extensive testing
• Monitoring the target species
and the bio-control agent is
important
• Host specificity testing
– Taxonomically associated plants
– Plant species growing in the same
habitat as target weed
– Important agricultural plant species
(Smith and van den Bosch, 1967; Pearson and Callaway, 2003)
Purple Loosestrife
Biological Control
• Releases (1992-2005)
• 1735 releases
– 800 sites
– 80 million beetles
• Evaluation (2005)
– 320 sites visited
– 31% significant
defoliation
Purple Loosestrife
Biological Control
Buckthorn
Biological Control
• Research began in 2001
• Potential agents identified
– 5-10 species of interest
• Host specificity testing 2003 present
• 4-6 years of testing remaining
(Gassman et al. 2002)
Garlic Mustard
Biological Control
• Research began in 1998
• Potential agents
– 4 weevil species
• Host specificity testing near
completion
• First release in 2007 or 2008
• Implementation
–
–
–
–
Establishing field sites
Developing rearing methods
Releases
Evaluation
C. scrobicollis
Tree/Shrub Control
Buckthorn-Honeysuckle-Barberry-Amur Maple-Elm
Control measures include:
– Pulling: be careful about soil
disturbance
– Chemical
• Treat cut stump with:
– Triclopyr—Garlon
– Glyphosate—Roundup
• Basal bark spray with:
– Triclopyr—Garlon 4
– Burning: long-term management tool
to reduce reinvasion
Tree/Shrub Control
Black Locust-Siberian Elm
Control measures include:
– Chemical
• Treat cut stump with:
– Triclopyr—Garlon
– Glyphosate—Roundup
• Basal bark spray with:
– Triclopyr—Garlon 4
– Manual
• Elm: girdle large trees, dig seedlings
• Locust: mostly ineffective
• Burning may reduce re-invasion (seek
out and remove seed trees)
Biennial/Short Lived Perennial
Garlic Mustard-Parsnip-Spotted Knapweed
Control measures include:
– Pull plant or cut tap root (collect
seed heads)
– Cut/Mow before seed production
(not effective with Knapweed)
– Summer burn
– Chemical: Treat areas of dense
cover with broadleaf herbicide
(non-target impacts a problem)
– Burning: long-term management
tool to increase native plant cover
Biennial/Short Lived Perennial
Garlic Mustard-Parsnip-Spotted Knapweed
Develop a plan that
Fall:
plant
Growing
integrates plant season
dies
burn
biology into the
land management
tools you use
Seed reduction or
elimination is key!
Seed may be viable Mow/
Cut/dig
for many years.
2nd
Summer:
Plant
flowers and
sets seed
Spring:
seeds
germinate
Herbicide
1st
Summer:
develops
rosette and
large root
Winter:
Plant
dormant
Dig
Perennial
Reed Canary Grass/Thistles
Control measures include:
– Dig if very small patch
– Chemical treatment of small patches (non-target
impacts a problem)
– Cover with shade cloth
– Cut/Mow before seed production
– Mow multiple times/year
– Mow followed by herbicide
– Burn prior to herbicide
These are difficult to control, and will
take many years of treatment!
Monitoring
• Can be as simple as photo plots
• Can be as complex as experimental designs
testing different management techniques
• Monitoring is key to
understanding if we
are accomplishing our
management goals
Before
After