Regional Invasive Plant Environmental Impact Statement

Frequently Asked Questions

The Questions asked below

1. What are weeds?

2. Do weeds differ from invasive plants, exotics, or aliens? Why is this an 'invasvie plant' page?

3. What is a noxious weed?

4. Why are invasive plants a problem?

5. Where do invasive plants come from and how do they get here?

6. How are these plants spread?

7. What can I do to stop the spread of invasive plant species?

8. How can native ecosystems be protected from invasive plants?

9. What are the methods for controlling invasive plants once they become established?

10. Why are you writing an Environmental Impact Statement (EIS) for invasive plants?

What are weeds?

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 'invasvie plant' page?

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:

http://pi.cdfa.ca.gov/weedinfo/ 

• This is the California Department of Food and Agriculture “Encycloweedia”.

  http://www.mtweed.org/Identification/identification.html 

  This is the Montana Weed Control Association weed identification site.

  http://www.invasivespecies.gov/index.shtml  

  This is the USDA Invasive Species website and contains lots of information on Federal noxious and invasive species management.

  http://www.agf.gov.bc.ca/croplive/cropprot/weedguid/weedguid.htm 

  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:

http://parks.state.co.us/cnap/IWM_handbook/IWM_index.htm

 

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.

http://tncweeds.ucdavis.edu/handbook.html

Why are you writing an Environmental Impact Statement (EIS) for invasive plants?

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-effective. 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

USDA Forest Service - Region Six - Invasive Plant EIS
Last Modified:  12/15/05