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5.1 Historical Land Use

5.1.1 State Level Land Use Changes

Between 1945 and 1992, two major changes in land use occurred: (1) the area of urban and rural transportation uses roughly tripled from 2.1 percent to 6.6 percent of land area and (2) agricultural uses declined. This finding is consistent with population growth observed over the same period. Total agricultural uses (cropland plus pasture) declined from about 33 percent in 1945 to about 28 percent in 1992 (Table 1). In contrast, forest area has been roughly constant. It was about 56 percent of the South in 1992 and ranged from a low of 55 percent in 1945 to a high of 60 percent in 1964.

Trends varied considerably among States (Figure 1). In Florida, area of forest declined from 66 percent of the land area in 1945 to 45 percent in 1992. Between 1945 and 1974, area of land in agriculture increased steadily. Since 1974, growth in urban uses and rural transportation uses has dominated. In 1945, 3 percent of Florida was in a human-dominated use; by 1992, that area had risen to 12 percent.

Georgia, Alabama, Tennessee, Kentucky, and the Carolinas all experienced declines in agricultural land uses from 1945 to 1964, with compensating gains in forestland. Other States had relatively stable agricultural area over this period. In all States, forest is the dominant land use, but the degree of dominance has changed in many States (Figure 1).

The pattern of change for forestland also differs among States. With the exceptions of Arkansas, Florida, and Louisiana, all States had more forestland in 1992 than they did in 1945. In the eight States with gains, land use shifted strongly from agriculture to forest between 1945 and 1969. Georgia, North Carolina, and Virginia have experienced declines in forest area since the early seventies. Over the same period, area in forest has been essentially stable in Alabama, Kentucky, Mississippi, South Carolina, and Tennessee.

Data from the National Resource Inventories provide the most recent measures of land-use change in the United States. The predominant patter of change between 1982 and 1997 has been an erosion of the total area of cropland and an increase in the area of developed uses. The total area of pasture and forest declined only slightly between 1982 and 1997 (Figure 2). Most of the urban land uses and the observed increase in urban land uses was concentrated in the five States along the Atlantic Coast from Virginia to Florida. These States all had more than 7 percent of their nonfederal land in urban uses (Figure 3). These States plus Tennessee had the highest growth in the percent of land in urban uses from 1982 to 1997. In these States, 3 to 6 percent of nonfederal land was developed over this period.

The preceding data describes net change in land use. There can be considerable offsetting changes between land uses that are not revealed by measures of net change. While we could not derive gross changes at the State level from the available NRI data, the 1997 NRI report indicates that 9.6 percent of all rural nonfederal land in the United States experienced a land use change between 1982 and 1997. That number is likely to be higher in the East, where the share of private lands is much higher than in other regions. Land-use data from forest inventories described in HLTH-1 reveal that over the past 20 years 2-3 million acres per year experience a change either from foret to nonforest or vice versa. These changes imply a significant impact on the condition of forests and their ability to provide wildlife habitat (see TERRA-3), recreation (SOCIO-6), and environmental amenities (SOCIO-7 and Alig, Dicks and Moulton 1999).

5.1.2 County level land use changes

County-level data show that major changes in land use occurred between 1982 and 1992 even though many Statewide totals were essentially unchanged (Figure 4). Forest area in southern and central Alabama and Mississippi rose at the expense of agricultural uses (Figure 4A and 4C). Similar shifts toward forest occurred in the Upper Coastal Plain of South Carolina and Georgia, in northern and western Kentucky, and in western Tennessee.

Loss of forestland was generally concentrated in areas of rapid population growth and urbanization. Population growth was most substantial around Atlanta, GA; Washington, DC; Richmond, VA; Raleigh and Charlotte, NC; Nashville, TN; Charleston, SC; and the coastal cities of Florida. Some forest loss was also associated with expanding agricultural uses in east-central Arkansas, and in parts of Kentucky, Louisiana, and North Carolina.

These county-level changes were aggregated to measure change by ecological section of the South. Forest loss was concentrated in the eastern part of the region (Figure 5 and Table 2). The Florida Coastal Lowlands and the Atlantic Coastal Flatlands --essentially the Atlantic Coast of the South--had the highest percentage losses of forestland (3.7 and 2.6 percent loss, respectively). The Southern Unglaciated Allegheny Plateau, the Northern Cumberland Plateau, and the Southern Ridge and Valley also experienced relatively high losses. Another large contiguous block that includes the Northern Cumberland Mountains, the Mid-Atlantic Coastal Plain, the Blue Ridge Mountains, and the Southern Appalachian Piedmont lost more than 600,000 acres of forest.

Forest gains between 1982 and 1992 were concentrated mainly in the western half of the South, especially the Middle Coastal Plain of Alabama and Mississippi. On the western side of the Mississippi River, gains were recorded in the Interior Lowland Plateau, the Oak Woods and Prairies, and the Eastern Gulf Prairies and Marshes.

5.1.3 Driving Variables

Agriculture Land Rent. Changes in the relative values of agricultural and forestland uses can cause shifts from one use to another (Alig 1986). To measure change in agricultural returns, we examined farm rents for the period 1960-1994. Figure 6 shows rents for five States in the South that are typical of patterns for all others in the region. It shows that real agricultural rents declined in the South in the 1980's but does not show the variation that occurs within a State where specific rents depend on local site factors.

Timber Prices. Timber prices have also changed substantially over the last 30 years. Figure 7 shows that both pulpwood and sawtimber prices increased rapidly between 1970 and 1980, declined in the early 1990's, and then rose again through the late 1990's. Between 1986 and 1996 the real price of pulpwood increased by about 50 percent, while the real price of softwood sawtimber more than doubled. These changes translated into rising timber rents. As a result, we can infer that the agriculture to forestry rent ratio has fallen markedly from the mid 1980's on.

Population. A critical determinant of the amount of forest in a county is its population density. Population of the South has grown steadily between 1940 and 2000 (Figure 8). Since 1980, the region's growth has outpaced the growth in the U.S. population as a whole, indicating an increase in the share of the nation's population living in the South. Between 1970 and 2000, the share of the U.S. population in the 13 States of the Assessment area grew from 27 to 33 percent.

Growth in population has not been uniform across space or across time. Population growth between 1950 and 2000 was concentrated in the Southern Appalachian Piedmont and along both the Atlantic and Gulf Coasts (Figure 9A). Population density declined in rural portions of the Coastal Plain in Alabama, Mississippi, Arkansas, and Georgia. While population generally declined in rural areas and increased in urban areas in the 1960's (Figure 9B), by the 1990's nearly every county in the South was experiencing some population growth (Figure 9C).