Verteilungsmuster der Pflanzen am Waldboden und Deren Ursachen

Abstract

Spatial patterns of forest-floor plants. — In the course of causal analysis of vegetation methods combining both area-based and individual-centred approaches are needed. In nine oak-pine stands individuals of all species present in the field layer were counted within 25 adjacent 2 x 2 m plots once a year from 1986 to 1988. On the basis of these plots and larger units (20 m2) the distribution of individuals was investigated using the measure of relative variance. Patterns were compared with measurements of relative light intensity. Three-year succession was studied on the basis of total numbers as well as by comparing patterns year by year. The clumping of individuals was found to be common among many forest floor species but less among seedlings and saplings of trees. In some cases the amount of light explains the pattern of occurrence, in others it may be due to other environmental factors or caused by intrinsic properties of the species. Over three years populations of several species showed more or less intense fluctuations in concordance with annual precipitation.