The Northern Appalachian Plateau and Uplands ecoregion is located in south-central New York and north-central Pennsylvania and covers approximately 29,900 km² (11,550 mi²) (fig. 1). The ecoregion is defined as a “transitional ecoregion between the less irregular, more agricultural and urbanized ecoregions to the north and west and the more mountainous and forested, less populated ecoregions to the south and east” (U. S. Environmental Protection Agency, 2002). The landscape is rural with rolling hills and fertile stream valleys. Forest and agriculture are the dominant land covers in the ecoregion. The forest consists of northern hardwoods that include sugar maple (Acer saccharum), red maple (Acer rubrum), white ash (Fraxinus americana), American beech (Fagus grandifolia), northern red oak (Quercus rubra), black cherry (Prunus avium), and eastern hemlock (Tsuga canadensis) (Smallidge, 1997). Dairy and cattle farming, along with the production of corn, wheat, and hay, are the major agricultural activities in this ecoregion (Fick and Cox, 1995). The climate is temperate with an average January temperature of –6.1^oC (21^oF) and an average July temperature of 20.7^oC (69^oF), with more than 940 mm (37 in) of precipitation annually (National Oceanic and Atmospheric Administration, 2002).

Figure 1: Northern Appalachian Plateau and Uplands Ecoregion showing the location of the sample blocks used in the study. Click on image to enlarge

Compared to other ecoregions of the Eastern United States (fig. 2), the overall estimated change between 1973 and 2000 for the Northern Appalachian Plateau and Uplands was quite low, just 2.4 percent (718 km² or 227 mi²). An estimated 1.8 percent (538 km² or 207 mi²) of total land area changed land cover once, and the area undergoing multiple changes was estimated at just 0.6 percent (209 km² or 80 mi²) (table 1).

The estimated change per time period varied modestly during the study period. The first two time intervals, 1972 to 1980 and 1980 to 1986, experienced a change of 0.7 percent. The third time interval, 1986 to 1992, had the only increase in change from 0.7 percent to 1.0 percent. Finally, in the last interval, 1992 to 2000, the total change was 0.8 percent. The margin of error at the 85-percent confidence level was very low during all time periods. The average annual rate of change for all time intervals was 0.1 percent, with the exception of the 1986 to 1992 time interval, which had a rate of change of 0.2 percent (table 2).

Table 1: Estimated overall spatial land cover change between 1973 and 2000 is 2.4%

Table 2: Estimated change and average annual change (normalized to account for varying time intervals) for each time interval

Figure 2: The overall spatial change in all Eastern U.S. ecoregions. Each bar chart shows the proportion of the ecoregion that experienced change on 1, 2, 3, or 4 dates. Click on image to enlarge

Figure 3: Estimates of land cover change per time interval normalized to annual rates of change. Click on image to enlarge

Table 4: Leading land cover conversions are listed for each of the four time intervals and for the entire study period

Figure 4: Net Change of Land Cover Categories per Time Period Click on image to enlarge