Structure and Succession in the Tree Stratum at Lake George, New York

Abstract

Tree species composition in 55 randomly selected stands from the south drainage basin of Lake George, New York, USA was analyzed by Bray—Curtis polar ordination and cluster analysis. The ordination revealed discrete groups of stand types that corresponded closely with those delineated by cluster analysis. Since the sample was unbaised, representative, and minimally distorted by the analysis, real discontinuities were presumed to exist in the vegetation. Most gaps between clusters were attributed to discontinuities in either (a) environmental factors or (b) rates of compositional change. Successional roles of the three major dominants, hemlock (Tsuga canadensis), beech (Fagus grandifolia), and sugar maple (Acer saccharum) were also assessed with the aid or ordination and cluster analysis. Each of the three dominated in one major stand cluster and these stand types were interpretated as being successionally related. Present high levels of beech and sugar maple in the study area were thought to have been promoted by logging in the late 1800's. Results of both ordination and size class analysis suggested that in many cases, sugar maple stands would change into be ech—hemlock stands, which would then change to hemlock. In contrast to reports from the Catskils and elsewhere, there was no evidence at Lake George that hemlock would be replaced by any other species in the absence of human disturbance. Since disturbance has been eliminated over large areas, long term increases in hemlock are predicted.