CORRELATION BETWEEN STAND STRUCTURE AND GROUND VEGETATION - AN ANALYTICAL APPROACH

The effect of stand structure on the diversity of the forest's ground vegetation was examined based on data on permanent sample plots collec ted in the northern parts of North-Carelia, eastern Finland. Different ordination methods (DCA, GNMDS, LNMDS, and HMDS) were used together w ith the TWINSPAN classification method. The aim was to construct a bas is for classifying forests with respect to the biodiversity of the for est vegetation. Fertility and stand age showed the strongest correlati on with the variation in ground vegetation. Other important factors we re basal area, tree species composition, and crown cover. These variab les were important in the division of the sample plots into different classes. According to the diversity indices, species diversity was at its highest in young stands on fertile forest sites. As a result, twen ty-one different classes were formed based on the relative abundance o f understorey species. The variables with the highest correlation were used to describe the stand structure in these classes.