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Review the indicators
at a glance
Grasslands and shrublands cover vast tracts of the United States,
especially in the West. The sagebrush steppes of the Intermountain
West, the prairies of the Midwest and the Great Plains, and the
deserts of the Southwest and the intermountain West are all part
of this system, as are the Alaskan tundra and shrublands, and the
scrublands of Florida. Pastures and haylands, which are also part
of this system, are often treated as part of the farmlands landscape.
From bare-rock desert to lush coastal meadows, the diversity of
grasslands and shrublands is staggering, but their valueecological,
economic, and socialis often overlooked.
Lands dominated by grasses and shrubs are also widely referred
to as rangelands. The definition of rangeland has evolved
slowly over the past half-century, from one tied closely to livestock
production, to definitions that focus on the natural vegetation
found on the landgrasses, grasslike plants, other small broadleaf
plants, or shrubsand on the lack of intensive agricultural
management, regardless of how the land is used. Therefore, even
though the terms rangelands and grasslands and
shrublands are nearly synonymous, the latter may be less open
to misinterpretation by those who continue to associate the term
rangelands with livestock grazing.
What can we say about the condition and use of grasslands and
shrublands?
Fourteen indicators describe the condition and use of grasslands
and shrublands in the United States. Partial or complete data are
available for six of these indicators, four of which have a long
enough data record to enable reporting on trends. Of the eight indicators
for which data are not reported, seven have inadequate data for
national reporting, while one indicator requires additional development
before it will be possible to determine whether data are available.
After the following brief summaries of the findings and data availability
for each indicator, the remainder of this chapter consists of the
indicators themselves. Each indicator page offers a graphic representation
of the available data, defines the indicator and explains why it
is important, and describes either the available data or the gaps
in those data.
System Dimensions
Three indicators describe the dimensions of the grassland and shrubland
system. The first reports the acreage of the major types of land
cover: grasslands, shrublands, pasture, and tundra. The second tracks
such major land uses as livestock raising, intensive recreation,
or rural residences. The third indicator reports the fraction of
grassland area and shrubland area that is in patches of different
sizes.
- How much land is covered by grasslands and shrublands?
There are 683 million acres of grasslands and shrublands in the
lower 48 states, or about 36% of the total land area. In addition,
there are 178 million acres of pastures, some of whichespecially
if they are not cultivatedhave many of the qualities of
more natural grasslands. There are about 200 million
acres of shrubland and tundra in Alaska. It is clear that substantial
areas of grassland and shrubland have been converted to other
uses since European settlement: in fact, from 1982 to 1997 alone,
the net amount of non-federal grasslands and shrublands converted
to other uses was 11 million acres.
- How are grasslands and shrublands used? Data are not
available to report on the acreage used for livestock grazing;
oil, gas, and mineral development; rural residences; protected
areas; and intensive recreation. About 30 million acres,
or about 4% of all grasslands/shrublands in the lower 48 states
(excluding pastures), are under Conservation Reserve Program
(CRP) contracts involving planting to grassland/shrubland
cover types.
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