|
|
|
|
Kansas Study Area
|
 |
|
The prairie
biome, which once covered a vast expanse of the American Midwest,
is now greatly diminished (Whitney, 1994). Prior to European
settlement, habitats within the prairie's eastern ecotone
were an interlocking pattern of forest and prairie, determined
largely by the interaction of fire, topography, moisture,
soil type, and biotic factors (Anderson, 1990). Human interaction
with the landscape has since modified several of these controlling
variables. Along the prairie-forest ecotone it is now well
documented that woody species can invade grassland habitats
that are not burned, grazed, cultivated or mowed (Holt et
al., 1995) and it has been suggested that forest expansion
into the grasslands of this region has occurred within the
last 100 years (Abrams, 1986).
|
|
|
|
|
The Midland,
Kansas United States Geological Survey (USGS) Quadrangle, covering
125 km2 falls within the tallgrass prairie and eastern decidous
forest ecotone. Located near the geographic center of the conterminous
United States, the Midland Quad has a Midcontinental climate. One-third
of Midland Quad falls within Douglas County, Kansas, where a 1990
survey indicated that woodlands cover 12% of the county, grasslands
41%, croplands 41%, urban 3% and water 3% (Whistler et al., 1995).
In contrast to a natural area or wildlife preserve, this study region
was selected specifically because it has heavily felt the impacts
of human interaction for more than one hundred years. The Midwestern
United States is also an ideal environment for high-resolution multi-temporal
studies of forest cover. Agricultural agencies have collected aerial
photography of the region approximately every 10 years for the past
60 years and the landscape exhibits a near absence of significant
topographic features.
|
|
