In a flowerbed, a weed
might be a misplaced plug of grass.For a wheat farmer, a weed may be a patch of yellow mustard.Since The Forest Service’s
mission is“caring for the land
and serving people,” our weeds are those plants that harm our natural
resources or the people who enjoy them.
Do weeds differ from invasive plants, exotics,
or aliens?Why is this an
‘invasive plant’ EIS?
The terms alien, invasive, exotic and weed are
often used inter-changeably to describe unwanted plant species.As stated above, the term weed
represents any plant that is growing where someone doesn’t want it.The terms alien and exotic are used
interchangeably to describe an unwanted plant that has been introduced to an
environment by humans, or is non-native.Weeds may or may not be non-native.
Invasive species are distinguished from other
unwanted plants by their ability to spread (invade) into native
ecosystems.Invasive
species are typically non-native, however, not all non-native species are
invasive.
For the purposes of this EIS an invasive plant is defined as
“a non-native plant whose introduction does, or is likely to, cause economic
or environmental harm or harm to human health”.Non-native means, with respect to a particular ecosystem,
any species that is not native to that ecosystem.
What is a noxious weed?
The important distinction between noxious
weeds and the rest of the terms used above is that ‘noxious’ is a legal term
applied to a plant species designated as such by State and Federal law.Each State develops individual criteria
for determining which plants will be considered as noxious and then generates
a list unique to that State.States have developed laws that require the control or elimination of
noxious weeds by landowners.An
invasive plant may or may not be designated as noxious by a given State.For information on the Federal
Noxious Weed Law go to http://www.aphis.usda.gov/ppq/weeds/.
For information on which species are considered noxious by
State you can click the following link http://invader.dbs.umt.edu
to the Invaders Database.This
database, developed by Peter Rice at the University of Montana, is a
distribution database for invasive plant species in all Northwestern
states. It provides a list of all known noxious weeds in the northwest
states and links to web sites that list noxious weeds for all other States
and Canada. Also, each State department of Agriculture maintains a list
of noxious weeds. In most cases this information is available on the
Internet through the State agricultural extension service
Why are invasive plants a problem?
Invasive plant species are a problem on
National Forest for a wide variety of reasons including the following:
Invasive plants out-compete and eliminate native
plants.As invasive
populations rise, native species populations fall. This results in a reduction in species diversity, changes in
community structure and loss of ecosystem function.
Invasive plants can displace the
native plants that provide food and shelter for wildlife.Their presence also reduces the quantity and quality of forage
available for both big game and domestic livestock.Some invasive plants are poisonous or can cause injury to
wildlife and livestock.
Invasive plants increase soil erosion.Research has shown that invasive
species can reduce organic litter found in native bunch grass ecosystems and
cause increased topsoil loss during rainfall.
Invasive plants diminish or eliminate
recreation opportunities.Many
invasive plant species have thorns or spikes that are painful to
recreationists.The presence of
these plants also impacts the visual quality and general esthetics of the
recreation experience.In
addition, reduced forage and spawning habitat results in diminished hunting
and fishing opportunities.
Invasive plants can alter the natural
fire cycle of plant communities.
Invasive
species impact nearly half of the species currently listed as Threatened or
Endangered under the U.S Federal Endangered Species Act.A local example of this is the
encroachment of yellow star thistle on the Endangered MacFarlane’s four
o’clock in Hells Canyon.
The following are examples of health hazards
to the public from invasive plants:
A number of invasive plants such as leafy
spurge and diffuse knapweed can cause skin irritation or blisters.
Poison hemlock is extremely
poisonous if eaten and may cause death in a short period of time.
Many invasive plants cause
allergic reactions in susceptible humans.
Dense plant growth along public
rights-of-way can obstruct vision leading to vehicle collisions.
Many invasive plants (ex.
yellow star thistle) have painful spines that can cause injury to people.
Where
do invasive plants come from and how do they get here?
Most invasive plant species are
introduced to North America from Europe or Asia both accidentally and
intentionally.Examples of accidental
introduction include the transport of seeds or plants in the ballast of
ships, in the fleece and hair of livestock, in clothing, and as contaminants
in seed lots.Intentional
introductions are made for reasons including medicine, dyes, forage, erosion
control and ornamental plants.There are many
avenues for introduction beyond the examples given above.
In their native habitats, these species are
quite often found as small, well-behaved populations. Their populations are
kept to manageable levels by natural competition with other plants, insects,
pathogens and a host of other predators. It is not until the species
are removed from their habitat and their natural predators that their
invasive characters emerge.
How are these plants spread?
Invasive plants are spread in any number of
different ways: by human activity, birds, wildlife, domestic animals,
wind, water, and vehicles, to name just a few.
What can I do to stop the
spread of invasive plant species?
First, learn to identify invasive plant
species and report new sightings.Always make sure you record and mark the location, species (if known)
and the approximate size of the population. Give this information to
the nearest land management agency or extension service.The following websites are a good place to find information on
identifying invasive species:
This is the British Columbia Ministry of
Agriculture weed website with lots of pictures and information.
Informational brochures on noxious weed
identification are also available from National Forest offices.
Other actions you can take to reduce the
spread and impacts of invasive plants include:
Control invasive plants on your own
property.
Clean clothing and equipment that
may contain weed seeds before and after hiking, camping or backpacking.
Avoid traveling through patches of
invasive plants to avoid transporting seeds.
Brush seeds and plant parts off of
livestock and pets and discard in the trash before and after traveling on
trails or in back country.
Always use certified weed free forage
on National Forests and Grasslands.
Feed livestock weed free forage for at
least several days before riding into backcountry trails.
Avoid causing soil disturbance and
damage to native vegetation.
Stay aware of the issues
and help spread the word -
Many people still do not know about the menace of invasive species. Educate
your friends and family about the differences between invasive and
non-invasive plants.If you see
your nursery selling invasive species, tell them about this problem.Most nursery growers are interested
in avoiding problem species and will listen to your concerns.
How can native ecosystems be protected from invasive plants?
Protecting native ecosystems from infestation
by invasive plants requires that land managers develop an integrated approach
to management.This type of
approach is typically referred to as ‘Integrated Weed Management (IWM)’.The Forest Service defines IWM
as‘An interdisciplinary weed
management approach for selecting methods for preventing, containing, and
controlling noxious weeds in coordination with other resource management
activities to achieve optimum management goals and objectives.’The following components are the
foundation of a typical IWM plan:
Education
and Awareness – Education is a vital part of prevention.Education includes understanding both
the problem and the solutions.The more people become aware of the issues, the more effective we can
be in preventing introductions.The benefits of education are summed up by the following popular
quote- ‘spread the word, not the weed!’
Prevention
and Early Detection - There are a host of prevention techniques that aid
in prohibiting or limiting the introduction of invasive plants.Prevention is the cornerstone of any
successful program.This EIS
will provide Standards and Guidelines for prevention to all Forests in the
Region.Early detection is finding
and eliminating small new infestations of invasive plants before they require
costly control measures.
Inventory
– It is imperative to know where invasive plants are, and are not, present
within a given management area.This information is critical for focusing prevention efforts and for
prioritizing which species and infestations require treatment.
Treatment-
Preventing invasions from ever happening is the best solution, however, once
an area has been degraded by an invasive species, treatment may become
necessary.
Coordination
– Invasive plants do not respect jurisdictional boundaries.It is imperative that landowners work
together to develop management strategies that take a broad look at the
problem.
Monitoring,
Research, and Evaluation – Monitoring is an essential component of any
invasive plant program.Monitoring includes the repeated collection and analysis of
information and is necessary to evaluate the effectiveness of the program.
For a more thorough discussion of IWM see the
following website:
What are the methods for controlling invasive
plants once they become established?
When prevention fails and we are faced with
the need to control an infestation, the challenge is to determine which
control method is most effective, while being the least damaging to the
ecosystem.Often the best
approach to controlling invasive plants is to use an integrated approach that
includes a combination of control options. The types of control options
available include:
Biological Control- The introduction,
encouragement, and artificial release of insects and pathogens to deter
and/or control the growth and reproduction of invasive plants.
Cultural Control- The establishment or
maintenance of competitive vegetation, use of fertilizing, mulching, fire, or
grazing animals to control or eliminate invasive plants.
Manual Control- The use of any
non-mechanized approach to control or eliminate invasive plants (i.e.
hand-pulling, grubbing).
Mechanical Control- The use of any
mechanized approach to control or eliminate invasive plants (i.e. mowing,
weed whipping, disking, and burning).
Chemical Control- The use naturally
derived or synthetic chemicals called herbicides to eliminate or control the
growth of invasive plants.
For a more comprehensive discussion of control
methods clink this link to the Control Handbook produced by The Nature
Conservancy.
Why are you writing an Environmental Impact Statement (EIS) for
invasive species?
Our existing direction for managing invasive
plants in Region 6 is found in the 1988 EIS and Record of Decision (ROD) for
Managing Competing and Unwanted Vegetation and the accompanying 1989 Mediated
Agreement.These documents
focused on management of competing vegetation in forest plantations.While the ROD identifies prevention
as the preferred strategy for vegetation management neither the ROD, nor the
Mediated Agreement, thoroughly addressed the numerous issues specific to
preventing and treating invasive plants, nor do they identify standards or
practices that could be applied to prevent invasive plants from becoming
established.
The
purpose of our project is to develop clear and comprehensive Forest Plan
standards and guidelines that allow for more effective prevention and timely
management of invasive plants in the Pacific Northwest Region.Given the seriousness of the current
situation, National Forest managers need more operational flexibility with
reduced process, greater cost-effectiveness and timely responsiveness,
without increasing environmental risks.A new roadmap for prevention and site restoration, as well as a new
and expanded toolbox, including; biological, fire, mechanical, manual,
cultural, and chemical tools, are critical to successfully managing our
invasive plant problem.
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