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 300 years. Native plant and animal diversity has declined over teh past three decades, and is likely to continue to decline because of human population growth and associated development.
Langner, Linda L.; Flather, Curtis H. 1994. Biological diversity: Status and trends in the United States. Gen. Tech. Rep. RM-244. Fort Collins, CO: U.S. Department of Agriculture, Rocky Mountain Forest and Range Experiment Station. 24 p. https://doi.org/10.2737/RM-GTR-244.