Forest ecosystems of the Marietta Unit, Wayne National Forest, southeastern Ohio: multifactor classification and analysis

Abstract

Local forest ecosystem types were identified using an iterative approach consisting of reconnaissance, plot sampling, and multivariate data analysis. Canonical correspondence analysis (CCA) indicated that aspect and other environmental variables were highly correlated with the ground flora and canopy tree species. A multifactor classification comprising 10 ecological land type phases (ELTPs) was based on cluster analysis of the six most important physiographic and edaphic factors. The characteristic vegetation of each ELTP was specified by distinctive groups of mature canopy trees and of ground flora species identified by two-way indicator species analysis. Within this unglaciated area of southeastern Ohio, the majority of the landscape comprises moderately to steeply sloping terrain. Quercus dominated dry and dry-mesic ridgetops and slopes, while Liriodendron tulipiferaL. and Acer saccharumMarsh. dominated mesic slopes and wet-mesic ravine bottoms. In general, many of the 17 ecological species groups of ground flora plants were more closely related to the major environmental gradients than were six groups of canopy tree species. Multiple-response permutation procedures were used to corroborate the differences in these two vegetation layers among ELTPs. This classification system was developed to provide an ecological framework as the basis for ecosystem management on the Wayne National Forest. Resume : Des types d'ecosysteme forestier local ont ete identifies a l'aide d'une approche iterative comportant une reconnaissance, un echantillonnage par parcelles et une analyse multivariee des donnees. L'analyse canonique des correspondances a montre que l'exposition et d'autres variables environnementales etaient fortement correlees avec la flore