Biological Diversity: Status And Trends In The United States
A supporting technical document for the 1993 Update of the 1989 RPA
Assessment
Biological diversity in the United States is summarized in three
categories: genetic diversity, species diversity, and community/ecosystem diversity. Major
changes have occurred in the distribution and abundance of native diversity in the United
States over the past three decades. Continuing human population growth and associated
development are likely to have even more negative impact on diversity in the future.
Highlights include the following:
- Agricultural and other development activities have resulted in the
conversion of about 30% of the forestland and over half of the wetlands in the United
States, as well as most of the native prairies of the Midwest.
- Species population trends indicate declining populations for several
groups of species, including most ducks, forest interior birds, and Pacific salmonids.
- Wildlife management has resulted in numerous successful population
recoveries, such as deer, elk, and wild turkey.
- Federal forest and rangelands maintain a large share of the natural
diversity in the United States, but federal lands alone cannot guarantee the viability of
many species and communities.
Langner, Linda L.; Flather, Curtis H. 1994. Biological diversity: status
and trends in the United States. Gen. Tech. Rep. 244. Fort Collins, CO: U.S. Department of
Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 24 p.