Influence of forest management on stand structure in ravine forests

The aim of this study was to compare the forest stand structure in managed and unmanaged ravine forests. The study was conducted in the Carpathians and the Krakow-Czestochowa Upland (SE Poland). We used 24 plots, of which 13 were from managed forests and 11 from unmanaged areas. We used 12 metrics related to both living and dead trees. The density of large living trees, quadratic mean diameter and maximum diameter were higher in the unmanaged forests, while the total density of all living trees, percentage of dead trees and number of stumps were higher in the managed forests. In addition, we found only subtle differences related to dead trees. The point pattern analysis also showed differences in the spatial distribution of trees. In unmanaged forests, we found a tendency towards tree aggregation, which was significant in several plots at small distances (up to 5 m), thereby suggesting the common presence of trees with multiple stems. In managed forests, we did not find any significant deviations from random patterns. Our findings show that forest management significantly influences the stand structure in ravine forests. Surprisingly, although metrics related to dead trees are considered as the best indicators of naturalness, we detected only subtle differences between managed and unmanaged forests. The characteristics related to living trees performed much better when distinguishing between managed and unmanaged stands. This is probably due to the specific habitat conditions in ravine forests characterized by steep slopes and highly dynamic dead biomass. In addition, a lack of tree clusters in managed forests is probably a result of selective cutting of trees with multiple stems. Finally, we conclude that the analysis of stand structure is more sensitive for the detection of management than a comparison of the plant species composition.