# Plant Applications for Addressing

# Invasive Plant Species

Every day invasive plant species are threatening the conservation of our
nation's vital agricultural and natural resources. Forests and
rangelands are being contaminated, cropland production is significantly
reduced, streams and water ways are being choked with weeds so they no
longer function, and wildlife are losing habitat. This is just the
beginning of the destruction invasive plant species exact on our
nation's natural resources if they continue to advance. Because invasive
species are too numerous to list in a brief description, they are simply
referred to as **Invasive Plant Species**.

![Picture of yellow starthistle field and
flower.](media/image3.jpeg){width="2.2574803149606297in"
height="1.9755905511811023in"}![Picture of yellow starthistle field and
flower.](media/image4.png){width="0.7799212598425197in"
height="0.7929133858267716in"}

## An Effective Counter Assault 

Our best defense against invasive plant species is the development of
diverse plant communities with competitive desirable species capable of
preventing advancement and replacing the invasives when they are
controlled. Since 1935, the Plant Materials Program has been providing
solutions to address invasive species. These successes are often
overshadowed by introductions of new invasive species through our
borders in cargo ships, airplanes and automobiles. The traveler is often
unaware that they are making these introductions.

![Picture of purple
loosestrife.](media/image5.jpeg){width="1.7692913385826772in"
height="1.7208661417322835in"}study and release plants and develop
planting and management technologies for plant species that ultimately
can be used to help restore devastated areas. Additionally, Plant
Material Specialists are trained to plan appropriate conservation
treatments and work with partners to address these affected areas.

Through the Program's many studies aimed directly at invasive species,
they have helped develop methods to control or suppress many of these
plants. Additionally, the Program has found appropriate replacements for
many invasive plant species once they have been controlled. The Program
has developed management strategies to improve established plant
communities after invasive plants are controlled.

## Highlights of Invasive Species Studies at Plant Materials Centers

### Pullman PMC, Pullman, WA

Yellow starthistle is one of the most noxious and tenacious weeds found
on over 9.25 million acres of rangeland in the western U.S. Plant
Materials Program researchers are examining the effects of native stands
of bluebunch wheatgrass on invading yellow starthistle.

### Plant Materials Centers in Meeker, CO; Aberdeen, ID; and Los Lunas, NM

Cheatgrass, a winter-annual grass found in all 50 states, severely
alters the ecology of our western range and forestlands. PMCs are
evaluating native plant species adapted to compete with cheatgrass in
infested areas on range, forest and critical areas. Centers also are
evaluating the tolerance of desirable native plant species to herbicides
used to control cheatgrass and the use of introduced species as a bridge
for cheatgrass control and eventual long-term establishment of native
plant communities in cheatgrass-infested areas.

### Plant Materials Centers in Aberdeen, ID; Corvallis, OR; Elsberry, MO; Big Flats, NY; Beltsville, MD; Pullman, WA; and Los Lunas, NM 

Several PMCs throughout the nation are evaluating the ability of native
species to compete with invasive plants in riparian and wetland systems.
In New York, Oregon, Missouri, New Mexico, and Idaho, the Program is
evaluating several native herbaceous and woody wetland species for their
ability to compete with some of the worst invasives, including purple
loosestrife, Japanese knotweed, invasive thistle species and reed
canarygrass. In Missouri and Washington, techniques are being developed
that will improve re-establishment of native plants into areas currently
infested with reed canarygrass. In Maryland, propagation, production and
establishment methods are being developed for native aquatic species to
help prevent hydrilla invasion and improve aquatic habitat in the
Chesapeake Bay.

### Plant Materials Centers in Bridger, MT; Brooksville, FL; and Los Lunas, NM

![Picture of cogongrass.](media/image6.jpeg){width="1.895275590551181in"
height="1.6881889763779527in"}Highly disturbed areas, such as those
associated with minelands, saline sites, roadsides and highly acidic
sites, are very susceptible to invasion by noxious weeds. Several PMCs
are evaluating native plants which are especially adapted to these
difficult sites to help prevent infestation by noxious weeds such as
knapweed species, Canada thistle and cogongrass.

### Other Plant Materials Centers across

###  the country

All 27 PMCs are developing native plants for a variety of conservation
uses to combat and replace invasive plant species. For example, the
Booneville (AR) PMC is evaluating methods to establish native grasses in
existing stands of tall fescue to improve pasture quality. The Elsberry
(MO) PMC is developing native shrub alternatives to Amur honeysuckle and
autumn olive for wildlife, buffer and shelterbelts plantings. In
addition, the Kika de la Garza (TX) PMC is evaluating native grasses to
replace buffelgrass on rangeland.