DIFFERENCES IN FOREST STAND STRUCTURE BETWEEN FOREST OWNERSHIP GROUPSIN CENTRAL FINLAND

This study investigates the differences in the stand structure of fore sts on mineral soils between different forest ownership groups in five forestry districts in central Finland. The study area includes the fo restry districts of: Keski-Suomi, Pohjois-Karjala, Pohjois-Savo, Etela -Pohjanmaa and Keski-Pohjanmaa. The study is based on the sample plot tree data from the 8th National Forest Inventory of Finland (NFI). The comparisons between the ownership groups were made according to fores t site types and stages of stand development. The stand structure vari ables used were: the range of tree diameter distribution, the number o f tree storeys and the number of tree species. The number of tree stor eys was estimated from the diameter distribution using non-parametric kernel smoothing. The differences between the forest ownership groups were considerable. On moist heaths the forests in private ownership ha d a greater number of tree storeys and greater diameter range compared to those forests owned by forest industrial companies or by the state . On the dryish and dry heaths similar differences occurred in the num ber of tree species. Information on the state of forests based on larg e-scale inventory data is a valuable tool for the development of fores t management, regional forest management planning and even large-scale ecological planning. In the future, variables, such as those presente d and compared in this study, could also be used for monitoring the st ate of forest management and for forest product certification. (C) 199 7 Academic Press Limited.