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Related Information
Endangered,
Threatened and Sensitive Species
Invasive species impact
nearly half of the species currently listed as Threatened or Endangered under
the U.S Federal Endangered Species Act
(Flather et. al 1994).
One Regional example of this is the encroachment of yellow starthistle
on the Endangered plant MacFarlane’s four o’clock in the Hells Canyon
National Recreation Area. The
photos below show a broad view of the species habitat and a close-up of the
plants flowers. Just this summer
yellow starthistle was discovered in what would be the immediate foreground
of the habitat view.
MacFarlane’s
four o’clock habitat in Hells Canyon
Close-up
of - MacFarlane’s four o’clock flowers
This is just one example of
the threat posed by invasive plants to Threatened and Endangered (T & E)
species. Other threats include:
§
Invasive plants can out-compete and eliminate T &
E
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 T & E wildlife. Their presence reduces the quantity and quality of forage
available. Some invasive plants
are poisonous or can cause injury to wildlife.
§
Invasive plants increase soil erosion. Erosion can cause increase in the amount of sediment that
enters a stream and could negatively impact T & E fish.
Do you know how many T
& E species occur on National Forests in the Pacific Northwest? See tables below for the answer:
Table
of Threatened and Endangered Plants
Table
of Threatened and Endangered Animals
This page finishes up with
an article of invasive plants.
Aliens
Stole My Habitat! Article
by: Terry Rich -Bureau of Land Management; Bird Conservation - Summer
Nesting 1997 Pages 12-13.
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