Invasive Plants

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Invasive Plants

• What is an invasive plant?
• Why are these invasive plants
• such a problem?
• What are some common invasive plant species
  across the country?
• What we can do to prevent their spread?

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Definition of Invasive Species

• Definition Non-native or alien species to
  the ecosystem under consideration and whose
  introduction does or is likely to cause economic,
  environmental harm, or harm to human health.
• Alien species" means, with respect to a
  particular ecosystem, any species, including its
  seeds, eggs, spores, or other biological material
  capable of propagating that species, that is not
  native to that ecosystem.

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How did they get here?
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Invasive species

• Introduced for food, fiber, pharmaceutical ,and
  ornamental reasons
• 50,000 invasive plant and animal species are
  established in the U.S.
• 5000 plant species have escaped and now exist in
  U.S. natural ecosystems (Morse et al., 1995)

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Problems caused by invasive species

• Crowd out native plants and wildlife that depend
  on them.
• Disrupt ecosystem processes hydrology natural
  succession and pollination
• Cause soil erosion and change soil chemistry
• Create additional fire hazard

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Problem of Invasive Species

• Invasive plants represent 47 of the total flora
  of most states. This percentage continues to
  increase annually (Zheng et al., 2004)
• Cost 138 billion annually in the US (Pimental et
  al., 2000).
• USDAs budget at 990 million.
• USACEs budget at 55 million.
• Approximately 42 of Threatened and Endangered
  species are at risk because of invasive species
  (Pimental et al.,2000)

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Executive Order 13112Signed by President
Clinton, 1999.

• Establishes the National Invasive Species
  Council. Currently there are 13 Departments and
  Agencies on the Council.
• Purpose to prevent the introduction of invasive
  species and provide for their control and to
  minimize the economic, ecological, and human
  health impacts that invasive species cause
• The Council wrote the National Invasive Species
  Management Plan

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Definitions

• "Control" means, as appropriate, eradicating,
  suppressing, reducing, or managing invasive
  species populations, preventing spread of
  invasive species from areas where they are
  present, and taking steps such as restoration of
  native species and habitats to reduce the effects
  of invasive species and to prevent further
  invasions.

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10 Riparian invasive species

• NE Purple Loosestrife Japanese Stilt Grass
• SE Kudzu Japanese Knotweed
• SW Salt Cedar Giant Reed
• NW Cheat grass Common Reed
• Country wide
• Russian Olive Autumn Olive

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Invasive Plant Species of Arkansas
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Purple loosestrife Lythrum salicaria
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Purple loosestrife Lythrum salicaria

• Native to Europe, SE Asia, Russia, India
• Listed as a invasive plant in all U.S. states
  except FL.
• Invades and fills habitat niche and provides no
  wildlife food value
• Clogs waterways and sends millions of seeds into
  water system
• Brought here as an ornamental
• Change in nutrient cycling of N and alters
  wetland function (accelerate eutrophication)

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Japanese Stilt Grass Microstegium vimineum
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Japanese Stilt Grass
Microstegium vimineum

• Native to Asia, introduced 1919
• Invasive in 15 eastern states
• Carpets the Riparian bottomland with thick thatch
  that prohibits the growth of native plants
• It is physiologically adaptive and may alter soil
  conditions to benefit itself by increasing the
  pH, nitrification and nitrate

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KudzuPueraria montana Var. lobata
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Kudzu Pueraria montana
var. lobata

• Native to China, introduced in late 1876 at the
  Philadelphia Centennial Exhibition promoted as
  a forage crop. Also planted by the CCC to prevent
  erosion.
• Invasive in 22 states
• Positive growth response to increasing CO2
• Tolerant of nutrient-poor, compacted soils and
  drought conditions

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Japanese Knotweed Fallopia japonica
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Japanese Knotweed
Fallopia japonica

• Native to Asia, introduced in late 1800s aws an
  ornamental plant.
• Invasive to 36 states
• Grows in Zones 4 8, Herbaceous shrub to 3 m
  tall
• Preference for wet environments, riparian and
  disturbed areas
• A synonym for this plant (in some Floras) is
  Polygonum cuspidatum.

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Salt Cedar Tamarix ramosissima
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Salt Cedar
Tamarix ramosissima Ledebour

• Native to Eurasia and Africa
• Small tree, brought in as an ornamental
• Noxious weed in 13 western states
• Widespread in riparian systems, displacing other
  native plants.
• Water-use rates of Tamarix are among the highest
  of any phreatophyte evaluated in the S.W. and
  lowers the water table (can consume 4 ac-ft of
  groundwater annually).
• Increases soil salinity salts redistributed from
  deep in the soil to the soil surface which
  inhibit other plant sp.

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Salt Cedar Tamarix ramosissima

• Control and Management
• Manual Digging, root cutting by any
• mechanical means, fire and flooding
• Chemical- General use herbicides such as
  glyphosate or triclopyr product approved for
  aquatic application. Follow label and state
  requirements.
• Biocontrol- 15 insects a mealybug (Tributina
  mannipara) and a leaf beetle (Diorhabda elongata)
  have been released. Leaf Beetle is impacting
  Endangered Willow Flycatcher habitat. Five other
  insects are being studied for release in the US.

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Giant Reed Arundo donax
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Giant Reed Arundo donax

• Native to India and countries around the
  Mediterranean sea
• Forms dense thickets which chokes riverside and
  stream channels
• Crowds out native plants and reduces wildlife
  habitat
• Creates fire hazard
• Small plant fragments can travel downstream and
  invade new areas

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Giant Reed Arundo donax

• Control and Management
• Manual Repeat mowing is necessary.
• Chemical- General use herbicides such as
  glyphosate. Apply to clumps after flowering.
  Prescribed burning alone or in combination with
  use of herbicide. Follow label and state
  requirements.
• Biocontrol agent from Europe being tested.

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Cheatgrass Bromus tectorum
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Cheatgrass Bromus tectorum

• Native to Europe, N Africa, SW Asia
• Invasive in 17 states
• Many ecosystems that Cheatgrass has invaded are
  seriously altered and no longer support the
  natural plant community and can maintain
  dominance for many years
• Grows in semi arid environment (10-22 annual
  precip.)
• Long awns can pierce animals feet, mouth, nose,
  eyes and ears
• It is a fuel, creating very hot fires in these
  grasslands

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Cheatgrass Bromus tectorum

• Control and Management
• Manual Mowing, grazing, fire and interseeding
  of competitive native plants
• Chemical- General use herbicides such as
  glyphosate. Follow label and state requirements.
• Biocontrol - Pink Snow mold (Fusarium nivale)
  is being investigated as a control agent.

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Common ReedPhragmites australis
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Common Reed Phragmites
australis

• Native to Europe and the fertile crescent.
• Eliminate diverse wetland native plant
  communities
• and provides little wildlife food or shelter
• Forms dense monoculture stands quickly and occurs
  in all 48 continental states.
• It can grow in a wide range of soil conditions
  in disturbed area, polluted soils, in somewhat
  dry sites and in water that is 6 feet deep

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Common ReedPhragmites australis

• Control and Management
• Manual Mowing may be effective.
• Burning plant after it flowers in
  August-September, but fire will stimulate growth
  in the Spring.
• Chemical - General use herbicides such as
  glyphosate. Follow label and state requirements.
• Biocontrol - No known bio-controls at this time.

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Russian Olive Elaeagnus angustifolius
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Russian Olive Elaeagnus angustifolius

• Native to southern Europe and western Asia
• Invasive in 31 states
• Interferes with natural plant succession and
  nutrient cycling and tax water reserves
• It is capable of fixing nitrogen and can grow on
  bare mineral substrate
• Birds will eat berries and spread this tree,
  however ecologists have found that bird richness
  is actually higher in riparian areas with native
  vegetation

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Russian Olive Elaeagnus angustifolius

• Control and Management
• Manual Mowing hedges with brush type equipment
  and removal of cut material.
• Chemical - General use herbicides such as
  triclopyr or imazapyr. Also Metasulfuron-methyl
  with a surfactant is also reported to be
  effective. After manual process will also need to
  stump treat with herbicide. Follow label and
  state requirements.
• Biocontrol None known at this time.

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Autumn Olive Elaeagnus umbellata
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Autumn Olive
Elaeagnus umbellata

• Native to Asia, introduced in the 1830s.
• Invasive to 23 states
• Shrub or small tree, grows in Zones 4 8 and
  spreads extremely rapidly
• Prolific seeding dispersed by birds and by
  water. Seed eaten by birds, but not
  preferentially.
• Can live in a wide range of habitats tolerant of
  infertile and dry soils. Can alter nutrient
  cycling

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Autumn Olive Elaeagnus umbellata

• Control and Management
• Manual Sprouts pulled by hand. Cutting will
  result in thicker, denser plants. Burning during
  the dormant season also results in vigorous
  re-sprouting.
• Chemical- General use herbicides such as
  glyphosate. Foliar application is effective. This
  is a nonselective herbicide, so care should be
  taken with other plants. Follow label and state
  requirements.
• Biocontrol None known at this time.

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Plantwise Guidelines

• Know your plants
• Use non-invasive alternatives
• Watch out for invasive plant hitchhikers
• Be careful if you share plants
• Use only seed mixes that are invasive plant free

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Plantwise Guidelines

• Use weed-free soil and mulch mix
• Be especially careful with aquatic plants
• Keep an eye on new sprouts and volunteers
• Dispose of invasive plants carefully
• If you cant part with your invasive plant,
  remember contain it, control it or cage it.

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Sources and websites

• http//www.invasivespecies.gov/.
• Plant Management Information System (PMIS)
• Aquatic Plant Information System (APIS)
• http// na.fs.fed.us/fhp/invasiveplants/weeds/inde
  x.shtm
• Huebner C.D. 2007. Invasive Plants Field and
  Reference Guide. NA-TP-05-04. USDA Forest
  Service.
• www.invasive.org Invasive Plants of the Eastern
  United States Identification and control
• Caronann.rifici_at_us.army.mil (for invasive
  sp.list serve)

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Review

• Definition of invasive species Non-native or
  alien species to the ecosystem under
  consideration and whose introduction does or is
  likely to cause economic, environmental harm, or
  harm to human health.
• Invasive plants are a problem because they crowd
  out native species, do not support our native
  fauna, cause native species to become threatened
  and endangered, alter the soil chemistry, alter
  hydrology and present a fire danger.

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Review10 Riparian invasive species

• NE Purple Loosestrife Japanese Stilt Grass
• SE Kudzu Japanese Knotweed
• SW Salt Cedar Giant Reed
• NW Cheat grass Common Reed
• Country wide
• Russian Olive Autumn Olive

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Contact information