What can be done about it?
The critical things to do are to learn how to recognize saltcedar,
to understand its negative impacts, and to know that it does not
belong in our natural habitats. Control and eradication programs
are being conducted throughout the western United States. Most of
these efforts are on public lands, but restoration projects are
also being conducted on privately owned nature reserves. The goal
of most of these control programs is to preserve or recover sensitive
areas, such as water holes or streams. In most cases, eliminating
massive infestations along major rivers is not economically feasible
at present.
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With such a large and widespread infestation, biological control
utilizing an imported insect pest of saltcedar is an optimal approach
to long-term management. In 2001, the first biocontrol agents, the
saltcedar leaf beetle (Diorhabda elongata), was released from caged
sites throughout the southwest. Another insect, the manna mealybug
(Trabutina mannipara) is being developed for release. Although the
hope is that these insects will be successful in reducing the saltcedar
problem, it is too soon to know how effective they will be.
Successful saltcedar control requires killing the root system.
Some control methods that have been effective are foliar herbicide
treatments, cutting the tree at the base and applying herbicide
to the cut stump, applying a systemic herbicide to the base of uncut
trees, ripping plants out by their roots with heavy equipment, or
spraying regrowth with a systemic herbicide after a fire. When existing
saltcedar plants are removed from an area, seedlings must be controlled
for at least one year to prevent re-infestation. Sensitive riparian
areas should be inspected at least once per year for new invasions
of saltcedar. Small saltcedar plants growing from seed can be easily
hand-pulled or sprayed with a systemic herbicide. This control effort
is difficult, time consuming and expensive. For more information,
or to make a contribution of your time and energy, please contact
the Bureau of Land Management at a District Office, CalEPPC (see
below) or The Nature Conservancy.
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Centaurea solstitialis
(yellow starthistle)
photo by Carl E. Bell
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A word about exotic pest
plants
Saltcedar is one example of an exotic (i.e. non-native)
pest plant causing large-scale ecological problems by taking over
vital habitat for native plant and animal species. Estimates vary
as to the number of exotic pest plant species that have made their
way into the western U.S. since the arrival of Europeans, but
there are probably thousands. Other examples are yellow mustards
and brooms along the coast of California, giant reed (Arundo donax)
clogging the rivers of coastal California and yellow starthistle
(Centaurea solstitialis), which infests 10-15 million acres of
range and public lands in the state. Most of these have become
so common they are mistaken for natives. The consequences of this
invasion for the natural areas of the western states are grave.
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