Species diversity of plants and fungi on logs of fallen trees of different species in oak-hornbeam forests

The aim of the study was to assess the species composition of vascular plants, bryophytes and fungi on logs in terms of the location of these logs, the species of the fallen tree, types of substrates and the degree of log decomposition. Investigations were conducted in oak-hornbeam forest in the “Grabina” reserve and forest strip adjacent to its southern borders and in oak-hornbeam forest in the “Pod Dziadem” reserve. Collected results indicate that the richness of herbaceous plant species on observed logs is higher in the “Grabina” area, while the richness of bryophytes and fungi is identical in both objects. Fungi inhabit mainly deciduous wood, which for them is the primary substrate. Bryophytes grow on wood of diff erent tree species at identical rate. The degree of bark overgrowing by bryophytes depends on the species of the host tree. On the analysed logs these bryophytes were found in biggest abundance which are capable of inhabiting diff erent types of substrate (the so-called generalists). They overgrow logs of all decomposition classes (I-V) and their proportion in the coverage of logs from individual classes ranges from to %. The fi rst vascular plants appear on logs starting from the nd degree of wood decomposition. Logs are being inhabited simultaneously by herbaceous plants and seedlings of trees and shrubs. Vascular plants are found fi rst of all on these logs, on which mats of mosses may act as substrates.