Zoology/Biology session

In Central Europe, the last two centuries have been dominated by rotation forestry management (RF), which creates homogeneous, even-aged forest stand. RF stands are characterised by high levels of disturbance to forest communities, while continuous cover forestry (CCF) results in multi-aged, heterogeneous forests. In Hungary, the share of RF accounts for 90% of the forest area, while the share of OA is less than 5% (including transitional forestry management), but in line with international efforts, the share of CCF is expected to increase in the near future. So it is particularly important to explore the ecological and silvicultural differences between the two management regimes.

The aim of the study was to compare the diversity and species composition of the understorey vegetation of RF and CCF management in a site-pair in the Mecsek Mountains. In two sample sites (one RF and one CCF), the understorey vegetation was investigated on a total of 40 sample plots for the comparison of species composition and diversity. For the understory analysis, all herbaceous and woody species below 50 cm in height were considered. General linear models, ordination methods and PERMANOVA test were used for data analysis.

In several aspects, the understorey vegetation levels of the CCF and the RF differ. The RF has a higher number of species, understorey vegetation cover, and a higher degree of canopy closure deficit (which gives an approximation of the amount of diffuse light). Closed forest species occurred with a higher relative frequency in the CCF, while disturbance tolerant, generalist and open vegetation species occurred in higher proportions in the RF. Overall, forest species were more abundant in the CCF. The proportion of annual species and perennial herbs was higher in the RF. Graminoids and woody species (incl. trees, shrubs, and subshrubs except blackberries (Rubus fruticosus agg.)) were more abundant in the CCF. The relative abundance of blackberries was significantly higher in the RF. Based on ordination, the understorey level of the two management types partially overlapped, but PERMANOVA analysis revealed a significant difference (p=0.003) between them.

Our results indicate, that the CCF is more efficient than the RF in maintaining the structural characteristics of natural forests. The CCF has a higher proportion of forest species, whereas in he RF, disturbance tolerant and generalist species are more abundant. CCF better preserves preserves the forest characteristics of the species and functional composition of the vegetation, and can therefore be more effective in conserving biodiversity.