Differences in Forest Stand Structure Between Forest Ownership Groups in Central Finland

This study investigates the differences in the stand structure of forests on mineral soils between different forest ownership groups in five forestry districts in central Finland. The study area includes the forestry districts of: Keski-Suomi, Pohjois-Karjala, Pohjois-Savo, Etelن-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 forest site types and stages of stand development. The stand structure variables used were: the range of tree diameter distribution, the number of tree storeys and the number of tree species. The number of tree storeys 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 had 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 number of tree species. Information on the state of forests based on large-scale inventory data is a valuable tool for the development of forest management, regional forest management planning and even large-scale ecological planning. In the future, variables, such as those presented and compared in this study, could also be used for monitoring the state of forest management and for forest product certification.