Vast rangelands cover nonfederal property in 17 western states, as well as portions of Louisiana and Florida. In order to understand the environmental quality of these important lands, researchers with the US Dept. of Agriculture and the US Geological Survey sampled more than 10,000 plots from 2003-2006; evaluated the condition of the soils, water, plants, and animals; determined the overall degree of degradation; and extrapolated that to all nonfederal rangelands.
They found that nationwide, about one of every five acres of these lands has some degree of degradation of at least one factor (soil and site stability, hydrologic integrity, and biotic integrity). The least damage is in North Dakota, at 4.9%; Utah suffers the most, at 43.8%. Much of the data for California is missing. About 10% of the rangeland is at least moderately degraded in all three categories. About 50% of these rangelands are burdened with non-native plant species.
There are many detailed maps in the report,  making it easy to tell what's happening in the areas of interest to your audience. In addition, summaries and details are broken out by region: Great Plains, Intermountain West, Southwest, Texas and Oklahoma, and Others (California and Florida).
More detailed results, at a finer scale, and using data collected in more recent years, is scheduled to be released by about the middle of 2011, says USDA Natural Resources Conservation Service spokeswoman Sylvia Rainford,  202-720-2536.