Panicum virgatum, commonly known
as switchgrass, is a perennial warm season grass
native to North America, where it occurs naturally from 55°N
latitude in Canada southwards into the United States and Mexico.
Switchgrass is one of the dominant species of the central North
American tall-grass prairie and can be found in remnant prairies,
in native grass pastures, and naturalized along roadsides in
a vanishing prairie landscape. Much of North America, especially
the prairies of the Midwestern United States, was once prime
habitat to vast swaths of native grasses, including Switchgrass
(Panicum virgatum), Indiangrass (Sorghastrum nutans), Eastern
Gamagrass (Tripsacum dactyloides), Big Bluestem (Andropogon
gerardii), Little Bluestem (Schizachyrium scoparium), and others.
In native prairies, switchgrass is historically found in association
with several other important native tallgrass prairie plants,
such as big bluestem, indiangrass, little bluestem, sideoats
grama, eastern gamagrass, and various forbs (sunflowers, gayfeather,
prairie clover, and prairie coneflower). These widely adapted
tallgrass species once occupied millions of hectares. As European
settlers began spreading west across the continent, the native
grasses were plowed under and the land converted to crops such
as corn, wheat, and oats. Introduced grasses such as fescue,
bluegrass, and orchard grass also replaced the native grasses
for use as hay and pasture for cattle. Due to accumulation
of loess and organic matter, parts of the North American tallgrass
prairie had the deepest topsoil ever recorded. After the steel
plow was invented by John Deere, this fertile soil became one
of America's most important resources. Over 99% of the original
tallgrass prairie is now farmland.
Icons of the Vanishing
A monumental earthwork depicting
the iconic and threatened Bison, Gray Wolf and Bald Eagle of
the vanishing prairies.
hunted almost to extinction in the 19th century and were reduced
to a few hundred by the mid-1880s. They were hunted for their
skins, with the rest of the animal left behind to decay on
the ground. After the animals rotted, their bones were collected
and shipped back east in large quantities. Link
Gray Wolf was once the world's most widely distributed
mammal, living north of 15°N latitude in North America.
Though once abundant, the gray wolf inhabits a very small
portion of its former range because of widespread destruction
of its habitat, human encroachment of its habitat, and the
resulting human-wolf encounters that sparked broad extirpation.
This reduction has been greatest in developed areas of the
United States because of poisoning and deliberate persecution. Link
Eagle It is estimated that in the early 1700s, the
bald eagle population was 300,000–500,000, but by the
1950s there were only 412 nesting pairs in the 48 contiguous
states of the US.
The Bald Eagle was severely affected in the mid-20th century
by a variety of factors, among them thinning of egg shells,
attributed to the use of the pesticide DDT. Other factors
in Bald Eagle population reductions were a widespread loss
of suitable habitat, and illegal shooting, which was described
as "the leading cause of direct mortality in both adult
and immature bald eagles," according to a 1978 report
in the Endangered Species Technical Bulletin. Link