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Economics Unit

Processes Driving Forest Fragmentation in the Southeast

Investigators:

John M. Pye, Southern Research Station
Raymond M. Sheffield, Southern Research Station
Karen J. Lee, Southern Research Station

Description:

The benefits which forests provide to natural and human systems is affected not only by the amount and type of forests but also by the configuration of these forests on the landscape. While natural disturbance agents such as hurricanes and catastrophic fires still affect this arrangement, their importance has been swamped in most regions of the South by the more purposeful agents of land use change, harvesting and regeneration. Understanding the factors which translate these decisions into spatial pattern is crucial to understanding how changing regulations or economic markets will affect the benefits we derive from our forests.

This study investigates several factors grouped into local, landscape and regional scales. Forest landowner group and topographic position reflect a very local scale of influence, forest cover, population density and urbanization constitute the landscape or county-level scale, while physiographic regions act at the broadest scale. Forest and fragmentation data were obtained from the Forest Inventory and Analysis Unit, Asheville, NC, while population information was obtained from the Census Bureau.

Multivariate analyses showed that: 1) the size of stands is strongly influenced by ownership group, with government and industry holding their forests in larger size patches, and farmers and miscellaneous private landowners keeping theirs in smaller sized stands, 2) stands are smaller in landscapes with less forest cover and/or higher human populations, and 3) accounting for changes in these factors could not remove the influence of time, indicating that additional processes are contributing to a pervasive decrease in stand size over time.

A follow-up analysis focused on identifying where on the landscape afforestation or deforestation activities occurred, what might be called the "zone of contention" between forest and alternative uses. This zone reversed itself on the landscape across the three physiographic regions investigated: in the coastal plain it was xeric sands and other upland locations most vulnerable to conversion, while in the Piedmont and mountains it was flatter or more mesic locations at greatest risk.

Problem Area(s): Landscape/stand models
Status: ongoing

Products:

Pye, J.M.; R.M. Sheffield; and K.J. Lee. in prep. The influence of social and other factors on declining stand size in the Southeastern U.S. Pye, John M.; Sheffield, Raymond M. 1997. Topographic characteristics of forests on the margin. In: The pace and pattern of landscape change; 12th annual symposium: United States Regional, International Association for Landscape Ecology; 1997 March 16-19; Durham, NC. [Place of publication unknown: [Publisher unknown]: p. 100. Abstract.

Pye, John; Lee, Karen; Sheffield, Ray. 1993. Effects of population on within-forest patch size in landscapes of the Southeastern US. In: Pattern and process in landscape ecology: 8th Annual U.S. Landscape Ecology Symposium; 1993 March 24-27; Oak Ridge, TN. Oak Ridge, TN: Oak Ridge National Laboratory. Program and Abstracts: 85-86. Abstract.

Pye, J.M. And R.M. Sheffield 1992. Recent patterns of forest fragmentation in the Southeast based on stand-level measures (poster). Ecol.Soc.of Amer.Bull. 73(2).

Pye, J.M. And K.J. Lee 1992. Influence of urbanization on forest landscape characteristics in the U.S. South (abstract). Proc. Fourth North American Symposium on Society and Resource Management, May 17-20. University of Wisconsin, Madison, WI.

modified: 13-MAR-2000
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