October 2006 Fish and Wildlife Habitat Management Leaflet Number 39

Invasive Species

© 1988 WHC

WILDLIFE HABITAT COUNCILSM

Introduction

Invasive species are one of the world’s leading threats 

to environmental health. Invasive species can be 

plants, animals, or other types of organisms. In their 

native range, plant and animal populations are generally kept in balance by factors such as competition, 

predation, and disease. If introduced into new geographic areas or if environmental conditions change 

substantially, species are sometimes freed from environmental constraints and can spread rapidly, becoming invasive and potentially overly abundant. Invasive 

species can have severe economic impacts and can 

wreak havoc on ecosystems and populations of native 

animal and plant species (see Key definitions).

The dispersal of and colonization by plant and animal species is a natural process that can be affected 

by human activities. Historically, birds and other wildlife colonized new areas very slowly as they moved to 

new areas, bringing with them plants and other animals that were contained in their digestive tracts or 

stuck to their fur or feathers. In general, the native 

species were best adapted to local environmental conditions and had an advantage over these new species. 

Depending on environmental conditions, the new 

plants and animals either died out or adapted to their 

new homes. While this process still happens today, 

the transport of potential invasive species has been 

accelerated because of increased global commerce. 

Furthermore, many ecosystems are increasingly susceptible to invasions because they have been degraded by inappropriate land uses.

Many of today’s invasive species are introduced to 

new areas through human activities such as recreation, transportation, and commerce. These introductions can be either intentional or accidental. Many 

plant and animal introductions have been intentional for food, fiber, ornamental purposes, or biological 

control of invasive species. For example, the common carp (Cyprinus carpio), introduced for aquatic 

plant control and recreational fishing, became an inU.S. Fish and Wildlife Service

The Asian Longhorned beetle (Anoplophora glabripennis), an invasive species, threatens hardwood 

trees in the northeastern United States.

Key definitions

Native species: a species that historically occurred or currently occurs in a particular ecosystem (other than as a result of an introduction). 

Native species have adapted over thousands of 

years to their surrounding plant and animal communities and local climate and soil conditions. 

Exotic species (also alien or nonnative species): a species, including its seeds, eggs, spores, 

or other biological material capable of propagating it, that is not native to a particular ecosystem. 

Invasive species: a species whose dominance 

causes harm to the economy or the environment. 

Invasive species can be native or exotic. Native 

species can become invasive if environmental 

conditions change substantially and the balance 

of the ecosystem is disrupted. Exotic species 

can become invasive when they are freed from 

the environmental constraints that are unique to 

their native range.
Invasive Species



vasive species that eats desirable plants and indirectly 

reduces water quality by increasing turbidity, thereby 

replacing or causing declines of some native fish species. On the other hand, introductions of many other 

organisms have been accidental. For example, zebra 

mussels (Dreissena polymorpha) were accidentally brought into the Great Lakes through ballast water 

discharged by ships. 

In the United States, invasive species are often 

thought of as species that come from other continents. However, invasive species in some regions of 

the United States are actually native to another region in the United States. For example, the bullfrog 

(Rana catesbeiana) is native in the eastern United 

States but is considered an invasive species west of 

the Rocky Mountains. Bullfrogs were introduced west 

of Rockies in the 1800s for human consumption. They 

have since proliferated and have disrupted the existing food chains by feeding on local amphibians. 

This leaflet is intended to serve as a brief introduction 

to invasive species for landowners. The potential ecological and economic impacts of invasive species are 

addressed. Case studies for six invasive species are 

presented to illustrate the diverse and often detrimental effects of these species invasions. General methods of control are presented, and various assistance 

programs are listed for landowners wishing to control 

invasive species on their land. 

Ecological impacts

The ecological impacts of invasive species can be 

both severe and wide-ranging. For example, invasive 

species can impact terrestrial and aquatic ecosystems, 

natural fire and water regimes, soil productivity and 

stability, and wildlife habitat and diversity.

Impacts on terrestrial ecosystems

In some terrestrial ecosystems, transformations by invasive species are so complete that the landscape itself has been changed. For example, bluegrass (Poa 

pratensis), often associated with rural Kentucky, is an 

invasive species from Eurasia that took over the region’s native vegetation after European settlement.

Invasive plants often grow in dense patches, displacing native plants and degrading wildlife habitat. 

Invasive species often have an advantage when competing with native species for food, water, and sunlight. For example, in coastal California, the iceplant 

(Carpobrotus edulis) takes up scarce water that native plant species would otherwise use. It forms a mat 

over native plants blocking sunlight and, on some 

California beaches, iceplant is destroying native vegetation that is the habitat for endangered species.

David R. Worley, Florida Departement of Environmental Protection, 

www.invasive.org

Water Hyacinth (Eichhornia crassipes) is an invasive 

aquatic plant species.

Steve Dewer, Utah State University, www.invasive.org

The tamarisk (Tamarix spp.) has invaded nearly one 

million acres in the western United States.
Invasive Species



Impacts on aquatic ecosystems

Aquatic invasive weeds are a significant problem in 

the United States. For example, exotic aquatic plants 

including hyacinth (Eichhornia crassipes), hydrilla (Hydrilla verticillata), and water lettuce (Pistia 

stratiotes) are disrupting native aquatic animal food 

sources and habitat, choking waterways, changing nutrient cycles, and reducing recreational use of rivers 

and lakes in Florida and several other southern states. 

Forty-four native fish species in the United States are 

considered threatened or endangered due to the presence of nonnative fish species.

Impacts on natural fire and water regimes

Some invasive plant species may affect native ecosystems by changing vegetation fuel properties, which 

can either promote or suppress fire. Many native species are adapted to a characteristic fire regime and 

can suffer when this fire regime is altered. If changes in the fire regime subsequently promote the dominance of the invasive species, an invasive plant/

fire regime cycle can be established. For example, 

European cheatgrass (Bromus tectorum) has invaded and spread throughout the shrub-steppe habitat 

of the Great Basin in Idaho and Utah, predisposing 

the invaded habitat to fires. Before this invasion, fire 

burned once every 60 to 110 years, and shrubs had a 

chance to become well established. Now, fires occur 

every 3 to 5 years, leading to a decrease in shrubs and 

other mid- and late-seral vegetation preferred by indigenous wildlife.

Invasive species can also alter an ecosystem’s natural water regime, causing water tables to rise or lower and, subsequently, making it difficult for native 

plants and animals to survive. For example, tamarisk 

(Tamarix spp.), has invaded nearly one million acres 

of flood plains, riparian areas, lake margins, and wetlands in the western United States. Due to the deep 

tap root and large water requirement of tamarisk, it 

may deplete water from desert sands, lowering water 

tables and drying up springs upon which some rare 

desert fish depend. 

Impacts on soil composition

Invasive plants can alter the physical or chemical 

composition of soils, making it difficult for native 

plants to survive. Often, invasive species help to increase the survival potential of other nonnative species, thus, profoundly altering the biotic community. For example, firetree (Morella faya), a native of 

the Canary Islands, is transforming soils in Hawaii 

Volcanoes National Park by fixing nitrogen 90 times 

faster than native plants. In this area, native plants are 

being displaced by nonnative species that are able to 

take root only on sites with fertile soils. Firetree also 

attracts the introduced Japanese white-eye (Zosterops 

japonicus), a competitor of several native bird species. 

Direct impacts on wildlife

Native wildlife can be negatively impacted by both 

plant and animal invasives. Invasive plants are spreading and invading approximately 1,700,000 acres 

U.S. Fish and Wildlife Service

The invasive brown tree snake (Boiga irregularis) 

prays on native wildlife on the island of Guam.

USDA, APHIS PPQ Archives, USDA APHIS, www.invasive.org

In Texas, the red fire ant is the target for millions of 

dollars in invasive species control.
Invasive Species



of wildlife habitat in the United States each year. 

Invasive animal species can reduce or even eliminate 

populations of native wildlife through predation, grazing, competition, and habitat alteration. Through predation, the brown tree snake (Boiga irregularis), a 

native of the South Pacific and Australia, has led to 

the extirpations of 10 native bird species, 6 native lizard species, and 2 native bat species on the island of 

Guam.

Threatened or endangered species or those whose 

natural range and population size are already limited are particularly vulnerable to invasive species. 

Approximately 42 percent of threatened or endangered species in the United States are considered to 

be at risk primarily due to competition with or predation by nonnative species.

Economic impacts

Invasive species have caused major financial losses 

in agriculture, forestry, and other economic sectors 

around the world. These species impact the economy through loss of potential economic output (loss of 

crop production, reductions in livestock fitness) and 

through the direct costs of combating invasions including quarantine, control, and eradication. For example, the glassy-winged sharpshooter (Homalodisca 

coagulata), an invasive insect in California, carries with it a disease that has caused nearly $40 million in losses of California grapes. The red fire ant 

(Solenopsis invicta) kills poultry chicks, as well as 

wildlife species such as lizards, snakes, and groundnesting birds. In Texas, $200 million per year is invested for controlling red fire ant. One study estimates 

that the total cost of invasive species in the United 

States amount to more than $100 billion each year.

For individual landowners, the economic trade-offs of 

invasive species can be complicated. Some invasive 

species are considered valuable forage for livestock, 

and others may reduce soil erosion. Furthermore, invasive plant species often require less time and effort to establish themselves than native species. In the 

past, the U.S. Department of Agriculture (USDA) promoted the use of some nonnative plant species (kudzu to decrease soil erosion) that quickly became invasive. However, as a member of the National Invasive 

Species Council (see Establishment of the National 

Invasive Species Council), the USDA now works to 

prevent the introduction of invasive species and to 

minimize the economic, ecological, and human health 

impacts that invasive species cause. Though there 

may seem to be some initial economic benefits associated with some nonnative species, landowners are 

strongly advised to encourage native species and discourage nonnative or invasive species wherever possible. In the long run, native species generally will 

provide more ecological and economic benefits than 

nonnative ones.

Case studies

The case studies that follow will give the reader an 

understanding of some of the most widespread and/or 

serious invasive species in the United States. The case 

studies include three invaders of terrestrial ecosystems, one of wetland ecosystems, and two of aquatic 

ecosystems. This list is by no means exhaustive and is 

simply intended to demonstrate the diversity of invasive species and the damage they can do. For a more 

comprehensive list of invasive species case studies, 

see www.invasivespeciesinfo.gov or http://www.issg.

org/database/welcome/. Although control methods 

are mentioned in this section, it is recommended that 

the landowner consult with natural resource professionals before undertaking an invasive species control 

plan for their specific situation.

Management and control

Eradication of invasive species is difficult and requires large inputs of time and money. Eradication is 

easier if an invasive species is detected early and an 

eradication plan is undertaken quickly. Some eradication efforts have been successful. However, the 

complete eradication of invasive species is often impossible, and efforts are more often focused on manEstablishment of the National Invasive Species Council

On February 3, 1999, President Clinton signed Executive Order 13112, establishing the National Invasive 

Species Council. Executive Order 13112 is intended 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 National Invasive Species Council is interdisciplinary and helps to coordinate and ensure complementary, cost-efficient, and effective federal activities regarding invasive species. 
Invasive Species

agement and control. Many invasions can be reversed 

or slowed, and infested areas can be restored to 

healthy ecosystems. 

Before attempting to manage or control invasive species, landowners must first learn what, if any, invasive species exist on their properties. The Natural 

Resources Conservation Service (NRCS) assessment protocol can assist landowners in determining to what extent invasives are present. Some invasive species may be well known to landowners, 

whereas others may be less well known. It is suggested that landowners begin by compiling a list of aquatic and terrestrial plants, animals, and insects that can 

be found on their own or adjacent properties. From 

this list, landowners can consult with local natural resource professionals to find out which species are invasive. Online invasive species databases may also be 

helpful in this regard. Many of these databases can be 

found at http://www.invasivespeciesinfo.gov/resources/databases.shtml. If invasive species are found to be 

present, the landowner can pursue management and 

control activities specific to those particular species.

Landowners should remember that methods used to 

control invasive species can both positively and negatively affect the ecosystem. The landowner must determine which control method or methods will be 

most effective in controlling invasive species while 

being least damaging to the ecosystem. It is recommended that landowners consult with local natural resource professionals before undertaking any invasive 

species management plan.

There are three main approaches to invasive species 

control: mechanical, chemical, and biological control 

methods. More often than not, invasive species control requires the combination of several methods. For 

example, cutting followed by herbicide applications is 

effective in controlling some invasive plant species. 

Mechanical methods

Mechanical methods for plants for controlling invasive species include pulling, cutting, or grazing; for animals, they include hunting, trapping, and exclusion 

by physical barriers. Mechanical methods can be extremely specific, minimizing damage to other organisms. Mechanical techniques are most effective when 

the invasive population is relatively small. For larger 

populations, mechanical controls can quickly become 

labor-intensive and cost-prohibitive. When using mechanical techniques to control invasive plants, the nature of the plant must be known in advance; sometimes plants can grow back much more quickly from 

the root system than they did initially. Frequently, 

these methods must be administered repeatedly to 

prevent the plant from reestablishing in a given area. 

Grazing—Depending on the invasive plant species, 

grazing can either promote or reduce its abundance 

at a particular site. Grazing is often combined with 

chemical or biological control methods to reduce or 

eliminate infestations. Grazing animals can also be 

used as part of a restoration program by breaking up 

the soil and incorporating seeds of desirable native 

plants. Animals should be brought into an infested 

area at a time when they will be most likely to damage 

the invasive species without significantly impacting 

the desirable native species. This can be done during 

seed or flower production of the invasive plant.

Burning—Many invaded habitats are best treated by 

restoring the ecosystem’s natural disturbances such 

as fires or floods. In particular, prescribed burning can 

be used in some areas to promote native plant and animal species. The most effective burns for controlling 

invasive plant species are often those performed just 

before flowers or seeds set or at the young seedling/

sapling stage. Repeated burns are sometimes necessary to effectively control invasive plants, and chemical methods may be required in combination with 

burning. Caution must be exercised and professional advice obtained since, in some cases, prescribed 

burns can promote an invasive species, such as when 

their seeds are specially adapted to fire or when they 

resprout vigorously.

NRCS

Grazing is often combined with chemical or biological 

methods to reduce or eliminate infestations.
Invasive Species

Chemical methods

Chemical methods involve the use of insecticides, 

herbicides, or other pesticides to kill the species in 

question. For example, herbicides and soil fumigants 

have been instrumental in the successful reduction 

of witchweed (Striga asiatica) from 400,000 acres 

to 15,000 acres in North Carolina. Unlike mechanical 

controls, chemical controls may not be specific to the 

species being controlled. In addition to killing the invasive species, pesticide applications can destroy native plants and animals if not applied properly and 

safeguards followed. Chemicals must be used carefully and according to the labeled directions to minimize 

harmful effects on nontarget species.

Biological methods

Biological control methods use organisms such as 

animals, fungi, or other microbes to feed upon, parasitize, or otherwise interfere with an invasive species. For example, South American alligator weed 

(Alternanthera philoxeroides) has been controlled 

in Florida and Georgia by the alligator weed flea 

beetle (Agascicles hygrophila), also from South 

America. Biological controls are not expected to eliminate the invasive species but rather to control their 

abundance. When the invasive species increases in 

numbers, the biocontrol organism increases correspondingly, causing the invasive species to decline. 

Biological control is often used for large infestations 

of invasive species; however, it may also be a viable 

option for landowners.

Biocontrols are carefully selected and screened to 

make sure they will not attack crops or nontarget species before they are certified for use. Although slower acting than mechanical or chemical controls, biological controls may be the best choice for long-term 

management of an invasive species problem. In general, biological control is cost-effective and the best alternative for stopping invasions which could consume 

production and support systems. Biocontrol continues to be the only potential method for controlling 

widely dispersed and inaccessible invasives like old 

world climbing fern (Lygodium microphyllum) in the 

Everglades.

Control of invasive species that are well established 

and that occupy large areas may require the use of 

two or more methods used at the appropriate times. 

Use of a number of methods for the control of an invasive or pest species is referred to as integrated pest 

management. For more information on integrated 

pest management options, refer to Fish and Wildlife 

Habitat Management Leaflet Number 24: Integrated 

Pest Management (IPM) and Wildlife. Immediate mechanical or chemical control of an invasive species 

followed by biological control may be the most effective approach for long-term management.

Robert H. Mohlenbrock, USDA NRCS Plants database, www.invasive.org

Biocontrols are used on aligator weed (Alternanthera 

philoxeroides) in Florida and Georgia.

University of Connecticut

Dense mats of hydrilla impede recreational use of 

lakes and rivers, but also provide food and refuge for 

wintering waterfowl.
Invasive Species

Terrestrial ecosystem invaders

European starling (Sturnus vulgaris)

Description: Medium-sized bird; in the summer, plumage is black with purple and green iridescence and bill 

is yellow and legs are reddish; in the winter, plumage 

is black with light colored tips on the feathers

Native range: Eurasia and North Africa

Invasive range: Throughout the United States

History: Introduced in New York in 1890 and 1891 by 

an individual who wanted all birds mentioned in the 

work of William Shakespeare to be established in the 

United States. In 1994, it was estimated that 140 million European starlings lived in North America.

Ecological and economic impacts: European starlings contribute to the decline of native bird populations through competition for resources and nesting 

space. They usurp other birds’ nests by contamination and physical competition. They can damage infrastructure and pose health risks to humans and livestock. European starlings cost hundreds of millions of 

dollars in agricultural damage each year due to consumption and contamination of livestock feed and 

stored grain and damage to fruit crops. On the beneficial side, European starlings do consume some insects and other invertebrate pests.

Control methods: Exclusion, trapping, shooting, poisons, tactile and sounds repellents, and startle devices

For more information, visit http://www.invasivespecies.gov/profiles/eurostarling.shtml.

Kudzu (Pueraria montana)

Description: Deciduous vine, 35 to 100 feet long, 

lobed three-leaflet leaves, large root crowns that increase in size with age

Native range: Japan and China

Invasive range: Most severe in the southeastern United States but can occur as far north as 

Connecticut and Illinois and as far west as Oklahoma 

and Texas

History: First introduced to the United States as an 

ornamental vine in 1876. Later, it was grown in southern states as a forage crop to reduce erosion and improve the soil. In 1935, the Soil Conservation Service 

began using it to prevent soil erosion on road cuts and 

farmlands. By 1955, kudzu had overtaken native vegetation and infrastructure in many areas. Today, kudzu 

has infested over 7 million acres in the Southeast.

Ecological and economic impacts: Kudzu blankets 

the ground and existing vegetation with a dense canopy through which little light can penetrate. Few plants 

can survive when covered by kudzu.

Control methods: Prescribed burning combined with 

herbicide application

For more information, see Driesch et al. Biological 

Control of Invasive Plants in the Eastern United 

States or Miller, J. H. Nonnative Invasive Plants of 

Southern Forests, or visit http://www.invasivespecies.gov/profiles/kudzu.shtml.

U.S. Fish and Wildlife Service

European starling

U.S. Fish and Wildlife Service

Kudzu
Invasive Species

Tree-of-heaven (Ailanthus altissima)

Description: Deciduous tree, up to 90 feet tall with a 

broad spreading crown of few branches, gray bark, 1- 

to 3-foot light green to reddish stalks divided into 12

to 30 pointed leaflets, flowers between April and July 

with small yellowish-green flowers, flowers develop 

into wing-shaped fruits on female trees

Native range: Eastern China

Invasive range: In the East, it is distributed from 

Massachusetts and southern Ontario south to Texas 

and northern Florida. Less abundant but still prevalent in the West, it grows from New Mexico west to 

California and north to Washington.

History: Introduced to North America on three 

distinct occasions. In 1784, it was introduced to 

Pennsylvania as an ornamental plant. In 1820, it was 

again planted as an ornamental in New York. Finally, 

Chinese immigrants during the gold rush introduced 

tree-of-heaven to California, probably due to its medicinal uses and cultural importance. Tree-of-heaven 

was available commercially by 1840.

Ecological and economic impacts: Tree-of-heaven 

colonizes disturbed, semi-natural habitats and riparian areas. It grows rapidly and forms dense stands, displacing native vegetation. It colonizes by root sprouts 

and spreads by prolific wind and water-dispersed 

seeds.

Control methods: Herbicides and cutting

For more information, see Miller, J. H., Nonnative 

Invasive Plants of Southern Forests, or visit http://

www.invasivespecies.gov/profiles/treeoheaven.shtml.

Wetland ecosystem invader

Purple loosestrife (Lythrum salicaria)

Description: Wetland plant, 1 to 4 feet tall, 30 to 50 

square stems, lance-shaped leaves that grow opposite 

each other on the stem or in whorls of three, spikes of 

purple flowers between June and September

Native range: Eurasia

Invasive range: Much of the United States, particularly serious in the Northeast and Upper Midwest

History: First introduced to the United States in the 

early 1800s, both accidentally (in ship ballast water) and intentionally (for medicinal and ornamental 

uses). Since 1880, its distribution has been increasing 

rapidly. 

Ecological and economic impacts: Purple loosestrife 

out competes native plants and reduces the availability of food and shelter for wildlife. It has caused reductions in 44 native plants and wildlife species including the endangered bog turtle, waterfowl, amphibians, 

and butterflies. Stands can grow to thousands of acres 

in size, eliminating open water habitat. Purple loosestrife costs $45 million per year in control methods 

and forage losses.

Control methods: Herbicides, hand pulling, and cutting. Digging should not be attempted because soil 

disturbance may enhance the spread.

For more information, see Driesch et al., Biological 

Control of Invasive Plants in the Eastern United 

States, or visit http://www.invasivespecies.gov/profiles/purplstrf.shtml.

Chuck Bargeron, University of Georgia, www.invasive.org

Tree-of-heaven

Bernd Blossey, Corness University, www.invasive.org

Purple loosestrife
Invasive Species

Aquatic ecosystem invaders

Eurasian water-milfoil (Myriophyllum spicatum)

Description: Submersed aquatic plant with many finely divided leaves that are limp when out of the water; 

long stems often branching at water surface, flowers 

on emerged spikes

Native range: Eurasia and North Africa

Invasive range: Throughout much of the United 

States, particularly problematic in the Northeast, 

northern Midwest, and Pacific Northwest.

History: First introduction difficult to determine 

due to past confusion with a similar native aquatic 

plant. Established in the United States by the 1940s, 

although may have been in the United States since 

1900 or earlier. Eurasian water-milfoil was probably 

brought to the United States on a commercial or private boat or possibly dumped from an aquarium. 

Ecological and economic impacts: The Eurasian water-milfoil grows rapidly in ponds, lakes, and pools 

of stagnant or slowly moving fresh to slightly brackish water, creating dense canopies at the surface that 

reduce light penetration. It reduces species diversity, fish spawning areas, and the abundance of native water plants, macroinvertebrates, and native fish. 

Recreational use of waterways is virtually impossible 

where the Eurasian water-milfoil grows.

Control methods: Mechanical methods and herbicides 

For more information, see Driesch et al., Biological 

Control of Invasive Plants in the Eastern United 

States or visit http://www.invasivespecies.gov/profiles/watermilfoil.shtml.

Zebra mussel (Dreissena polymorpha)

Description: Thumbnail-sized mollusk with a striped 

shell

Native range: Caspian and Black Seas

Invasive range: Most of the aquatic ecosystems in the 

eastern United States, from the Great Lakes through 

the Mississippi River drainage.

History: Accidentally introduced in 1988 to the Great 

Lakes from ballast water of a transatlantic freighter. In less than 10 years, zebra mussels spread to all 

five Great Lakes and into the Mississippi, Tennessee, 

Hudson, and Ohio River basins. 

Ecological and economic impacts: Zebra mussels reduce the availability of food and oxygen for native 

fauna. They cement themselves to any and all submerged hard surfaces and have been observed completely covering native mussels, clams, and snails, interfering with these native species’ feeding, growth, 

movement, respiration, and reproduction. Zebra mussel invasions could result in the extinction of up to 

140 species. Zebra mussels invade and clog water intake pipes at industrial and utility plants. Water treatment facilities have experienced fouling and loss of 

intake heads, obstruction of valves, corrosion of cast 

iron and steel piping, and buildup of methane gasses 

from the decaying mussel tissue. It is estimated that 

zebra mussels will soon cause $100 million per year 

in damages and associated control costs. On the other 

hand, zebra mussels act as filters and can help to drastically improve water clarity in lakes. Clearer water 

can increase recreational opportunities such as scuba diving. However, clearer water can also lead to increased vegetative growth, which can decrease opportunities for recreation. Generally, it is thought that the 

Alison Fox, University of Florida, www.invasive.org

Eurasian water-milfoil

Randy Westbrooks, U.S. Geological Survey, www.invasive.org

Zebra mussel
Invasive Species

10

negative impacts of the zebra mussel largely outweigh 

its positive impacts.

Control methods: Remove attached vegetation and 

wash boats or trailers before moving them to new 

lakes or rivers.

For more information, visit http://www.invasivespecies.gov/profiles/zebramussel.shtml or http://el.erdc.

usace.army.mil/zebra/zmis/.

Assistance programs

Various public and private organizations are available to provide technical and financial assistance to 

landowners interested in improving wildlife habitat 

by controlling invasive species. Table 1 lists some of 

these organization and specific programs.

Conclusion

Invasive species pose a serious environmental threat. 

They can destroy wildlife habitat, disrupt ecosystem 

functions, and impact native plant and animal populations. Interference with agriculture and other commercial land uses may require expensive solutions. 

Invasive species problems must be approached in 

a coordinated, well-planned manner for successful 

treatment of their damaging effects. With advice and 

assistance from natural resource professionals, conservation organizations, and government agencies, 

landowners can take a proactive approach to eradicating and/or managing invasive species on their land.
Invasive Species

11

Program Description Land eligibility Opportunities for invasive 

species management

Contact

Conservation 

Reserve 

Program

Up to 50% cost-share for 

establishing permanent 

cover and conservation 

practices, and annual 

rental payments for land 

enrolled in 10- to 15-yr 

contracts 

Highly erodible land, 

wetland, and certain other 

lands with cropping 

history, stream-side areas in 

pasture land

Annual rental payments may 

include an additional amount up 

to $5 per acre per year as an 

incentive to perform certain 

maintenance obligations 

including invasive species 

management activities

NRCS or FSA 

State or local 

office

Conservation 

Security 

Program

Financial and technical 

assistance to promote 

the conservation and improvement of soil, 

water, air, energy, plant 

and animal life, and other conservation purposes

Tribal and private working lands in selected watersheds, including cropland, 

grassland, prairie land, improved pasture, range land, 

and forested land

Technical and financial assistance available for invasive 

species management

NRCS State 

or local office

Conservation 

Technical 

Assistance

Technical assistance, 

including conservation 

planning, design, and 

implementation, to help 

preserve, maintain, and 

improve natural 

resources

Private, Tribal, and other 

non-Federal lands

Technical assistance available 

for invasive species management

NRCS State 

or local office

Cost-share and incentive 

payments for conservation practices in accordance with 1- to 10-yr 

contracts

Cropland, range, grazing 

land, and other agricultural 

land in need of conservation

Incentive payments may be 

provided for invasive species 

management as a component of 

a larger land management plan

NRCS State 

or local office

Grassland 

Reserve 

Program

Financial incentives, 

technical assistance, and 

cost-share for enhancement and restoration of 

grasslands in permanent 

or 30-yr easements or 

rental agreements

Restored, improved or natural grassland, rangeland, 

pastureland, shrubland, and 

certain other lands

Participants must follow a sitespecific grassland resources 

conservation plan, which can include invasive species management. Land threatened by invasive species is prioritized for 

program eligibility

NRCS State 

or local office

Partners 

for Fish 

and Wildlife 

Program

Up to 100% financial and 

technical assistance to 

restore wildlife habitat 

under a minimum 10-yr 

cooperative agreement

Most degraded fish and/or 

wildlife habitat

Restoration projects may include removing of invasive 

plants and animals that compete 

with native fish and wildlife and 

alter their natural habitats

U.S. Fish 

and Wildlife 

Service 

local office

Waterways 

for Wildlife

Technical and program 

development assistance 

to coalesce habitat efforts of corporations 

and private landowners 

to meet common watershed level goals

Private lands Can provide State-specific advice and/or contacts for invasive 

species management projects

Wildlife 

Habitat 

Council

Table 1 Example assistance programs for invasive species management 
Invasive Species

12

Program Description Land eligibility Opportunities for invasive 

species management

Contact

Wetlands 

Reserve 

Program

Up to 100% cost-share 

and technical assistance 

to address wetland, 

wildlife habitat, soil, water, and related natural 

resource concerns in an 

environmentally beneficial and cost-effective 

manner under 10-yr contracts, 30-yr easements, 

or permanent easements

Previously degraded wetland and adjacent upland 

buffer, with limited amount 

of natural wetland and existing or restorable riparian areas

Can provide technical and financial assistance for invasive species management provided these 

activities are consistent with the 

protection and enhancement of 

wetland habitats

NRCS State 

or local office

Wildlife at 

Work

Technical assistance on 

developing habitat 

projects into programs 

that allow companies to 

involve employees and 

the community

Corporate lands Can provide State-specific advice and/or contacts for invasive 

species management projects

Wildlife 

Habitat 

Council

Wildlife 

Habitat 

Incentives 

Program

Technical assistance and 

up to 75% cost-share 

assistance to establish 

and improve fish and 

wildlife habitat for 5 to 

10 yr

High-priority fish and wildlife habitatsCost-sharing is available to 

manage invasive species that 

have negative impacts on the 

habitats of declining wildlife 

species

NRCS State 

or local office

Table 1 Example assistance programs for invasive species management—Continued
Invasive Species

13

References

Online sources

The Invasive Species Specialist Group. 2005. Global 

invasive species database. http://www.issg.org/

database/welcome/ [Accessed 25 March 2005].

National Invasive Species Council. 2005. The nation’s 

invasive species information system. http://

www.invasivespecies.gov/ [Accessed 22 March 

2005].

The Nature Conservancy. 2005. Invasive species initiative. http://tncweeds.ucdavis.edu/methods.html

[Accessed 22 March 2005].

University of Georgia Bugwood Network, USDA 

Forest Service, and USDA APHIS PPQ. 2005. 

Invasive and exotic insects, diseases, and weeds: 

information and images. www.invasive.org

[Accessed 6 April 2005].

U.S. Army Corps of Engineers. 2002. Zebra mussel information system. http://el.erdc.usace.army.

mil/zebra/zmis/ [Accessed 25 March 2005].

U.S. Department of Agriculture National Agriculture 

Library. 2006. National invasive species information center. http://www.invasivespeciesinfo.gov

[Accessed 14 February 2006].

U.S. Department of Agriculture Natural Resources 

Conservation Service. 2006. Plants database. 

http://plants.usda.gov [Accessed 14 February 

2006].

Printed sources

Brooks, M.L., C.M. D’Antonio, D.M. Richardson, J.B. 

Grace, J.E. Keeley, J.M. DiTomaso, R.J. Hobbs, 

M. Pellant, and D. Pyke. 2004. Effects of invasive alien plants on fire regimes. BioScience 54: 

677–688.

Florida Cooperative Extension Service. 2001. 

European starling. Fact Sheet SS–WEC–118, 

Department of Wildlife Ecology & Conservation, 

Florida Cooperative Extension Service, Institute 

of Food and Agricultural Sciences, University 

of Florida. Available at: http://edis.ifas.ufl.edu/

UW118. 

Mack, R.N., D. Simberloff, W.M. Lonsdale, H. Evans, 

M. Clout, and F. Bazzaz. 2000. Biotic invasions: 

causes, epidemiology, global consequences and 

control. Issues in Ecology 5: 1–20.

Marinelli, J., and B. Hanson, eds. 1996. Invasive plants: 

weeds of the global garden. Brooklyn Botanical 

Garden, Inc., Brooklyn, NY.

Miller, J.H. 2003. Nonnative invasive plants of southern forests: a field guide for identification and 

control. Southern Research Station, Auburn 

University, Asheville, NC.

Pimentel, D., L. Lach, R. Zuniga, and D. Morrison. 

2000. Environmental and economic costs of 

nonindigenous species in the United States. 

BioScience 50: 53–65.

Stein, B.A., and S.R. Flack, eds. 1996. America’s least 

wanted: alien species invasions of U.S. ecosystems. The Nature Conservancy, Arlington, VA.

Tu, M., C. Hurd, and J.M. Randall. 2001. Weed control methods handbook: tools and techniques for 

use in natural areas. The Nature Conservancy. 

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

van Driesche, R., B. Blossey, M. Hoddle, S. Lyon, and 

R. Reardon. 2002. Biological control of invasive 

plants in the eastern United States. USDA Forest 

Service Publication FHTET–2002–04.
Invasive Species

14

Acknowledgements: Primary author: Raisssa Marks, Wildlife Habitat Council. Edited by Erika T. Smith, 

Wildlife Habitat Council. Drafts reviewed by Rob Pauline, Wildlife Habitat Council; William Hohman, Natural 

Resources Conservation Service; Dave Dewald, Natural Resources Conservation Service; Doug Holy, U.S. 

Department of Agriculture; James Miller, U.S. Department of Agriculture; Larry Allain, U.S. Geological 

Survey; Jim Dinsmore, Iowa State University

www.nrcs.usda.gov

Wildlife Habitat Council

8737 Colesville Road, Suite 800

Silver Spring, Maryland 20910

(301) 588–8994

The mission of the Wildlife Habitat Council 

is to increase the amount of quality wildlife 

habitat on corporate, private, and public land. 

WHC engages corporations, public agencies, 

and private, nonprofit organizations on a 

voluntary basis as one team for the recovery, 

development, and preservation of wildlife 

habitat worldwide.

www.wildlifehc.org

© 1988 WHC

WILDLIFE HABITAT COUNCILSM

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