Evaluation of an ecological land type classification system, Natchez Trace State Forest, western Tennessee, USA

In an effort to aid future research and forest management decisions, we incorporated data on forest type, soils and topography into a geographic information systems (GIS)-based ecological land classification system for Natchez Trace State Forest (NTSF) in western Tennessee. The area is still recovering from the effects of cultivation, logging, forest clearing and grazing during the 1800s and early 1900s, but the data indicated that most stands now contain sawtimber-sized trees after more than 50 years of secondary succession. Our analyses showed that forest types were not randomly associated with soil characteristics or topography. For example, the most heavily gullied lands were strongly associated with pine forests while hardwoods were more associated with upland soils and certain types of sideslopes. Mature hardwood stands, which were deemed to be of the greatest conservation value, were classified into eight ecological land types based on soil type, aspect, orientation and topographic setting for further study. When these land types were evaluated with respect to data on forest composition and environmental conditions collected in the field, we found that the variables used to derive the eight classes were important in influencing floristic patterns. It was, however, clear that the classes themselves imperfectly captured patterns of overstory community composition for a number of reasons. Thus, while land types provide a potentially valuable management tool, their utility and successful implementation are dependent upon a recognition of their inherent limitations.