Note that the data published in the 2002 State of the Nation’s Ecosystems Report as well as the 2003 and 2005 Web-Only Updates have been superseded by the 2008 Report and thus should be used with caution. For the most recent data, purchase the 2008 Report from Island Press.

Review the indicators at a glance

What makes a forest a forest is, obviously, the presence of trees: the giant redwoods of the West Coast; the maples, oaks, and hickories that give New England its flaming fall foliage; the trackless wilderness of interior Alaska; even the Pine Barrens of New Jersey—all these fit into the picture conjured up by the word “forest.” But forests also include the coastal live oak woodlands of California, the cypress swamps and savannahs of the South, and the pinyon–juniper woodlands of the arid Southwest. Highly managed timberlands are also forests. Many of these “forest” types overlap with, or even occupy the same space as, other ecosystem types (wetlands, grasslands and shrublands, farmlands, urban and suburban areas). These varied forest lands provide Americans with timber and other wood products, but they also offer the opportunity for solitude, hunting, hiking, birdwatching, and camping.

What can we say about the conditions and use of U.S. forests?

Fifteen indicators describe the condition and use of forests in the United States. Partial or complete data are available for twelve of these fifteen indicators; data are available for a higher percentage of forest indicators than for any other ecosystem. Seven indicators have a data record that is long enough to judge trends, and for one there is a regulatory standard for comparison. For three indicators, data are not adequate for national reporting. Nine of the twelve indicators for which data are available are presented by region, allowing comparison of conditions in different regions.

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 of the four indicators of forest system dimensions track forest acreage, each in a different way. These are total forest acreage, including the split between public and private ownership; the acreage of about 20 major forest types, each of which provides habitat for a different mix of plants and animals; and the percentage of forest under various management regimes, from planted timberland to national parks and wilderness areas, where timber harvesting is prohibited. Both the type of forest and the degree to which the forest is broken into smaller patches and intermingled with nonforest areas are important for many forest species, so the fourth indicator reports the percentage of forest surrounded by small, medium, and large expanses of more-or-less complete forest cover.

• How much forest land is there in the United States? How much is privately owned, and how much is publicly owned? Forests cover 749 million acres, or about a third of the land area of the United States, down from about 1 billion acres at the time of European settlement. The area of forest is divided about evenly between East and West, but most historic conversion of forest to other uses has taken place in the East. In recent decades, the overall acreage of forest has been relatively stable. In the East, more than 80% of forest lands are privately owned; in the West, about two-thirds are publicly owned.
• How is the area occupied by major forest types changing? Over the past several decades, the major forest types with the largest increases in acreage were oak–hickory and maple–beech–birch in the East, and fir–spruce in the West. Forest types declining in area included elm–ash–cottonwood, oak–gum–cypress, aspen-birch, and longleaf-slash pine in the East and hemlock–sitka spruce, ponderosa pine, and lodgepole pine in the West. Over this period, overall forest area changed very little, so reductions in area occupied by one forest type were generally balanced by increases in area by other types.