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Spruce forest, Oregon, July 2003.
Credit: National Oceanic and Atmospheric AdministrationBefore European settlement, forests covered nearly one billion acres of what is now the United States. Since the mid-1600's, about 300 million acres of forest have been cleared, primarily for agriculture during the 19th century. Today about one-third of the nation is forested. While total forest area has been relatively stable for the last 100 years (currently about 747 million acres), there have been significant regional shifts in the area and composition of the nation's forests. Reversion of marginal farmland in the east, large scale planting in the South, and fire suppression have contributed to increases in forest area. Urbanization, conversion to agriculture, reservoir construction, and natural disasters have been major factors contributing to loss of forests.
Eastern forests cover about 384 million acres and are predominantly broadleaf (74%), with the exception of extensive coniferous forests and plantations in the southern coastal region. These are largely in private ownership (83%). By contrast, about 363 million acres of western forests are predominantly coniferous (78%) and in public ownership (57%). Nearly ten million private individuals own about 422 million acres of forest and other wooded land. Most public forest land is held by four Federal agencies (Forest Service, Bureau of Land Management, National Park Service, Fish and Wildlife Service) as well as numerous state, county, and municipal government organizations. Major uses of forests include timber production, recreation, hunting, fishing, watershed and fisheries protection, wildlife habitat and biodiversity protection, and gathering nontimber products such as berries, mushrooms, and medicinal plants. The forest cover types found on the National Atlas Forest Cover Types wall map and map layer were derived from Advanced Very High Resolution Radiometer (AVHRR) composite images recorded during the 1991 growing season. Each composite covered the United States at a resolution of one kilometer. Field data collected by the Forest Service were used to aid the classification of AVHRR composites into forest cover types. Details on development of the forest cover types dataset are in an article written by Zhu and Evans (1994). |
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Eyre, F.H., 1980, Forest Cover Types of the United States and Canada: Society of American Foresters, 148p. Smith, W.B., Vissage, J.S., Darr, D.R., and Sheffield, R.M., 2000, Forest Resources of the United States, 1997: St. Paul, MN, U.S. Department of Agriculture Forest Service. Zhu, Z. and Evans, D.L., 1994, U.S. Forest Types and Predicted Percent Forest Cover from AVHRR Data: Photogrammetric Engineering and Remote Sensing, v. 60, No. 5, p. 525-531. |
