ZLV Online

Natural montane fir-beech forests are frequently replaced by spruce plantations in Central Europe. Significant impact on understorey species diversity is expected. However, mechanisms of dominant tree influence on the understorey have not been completely revealed yet. The aim of the study is to determine changes of herb layer composition and diversity in managed forests with altered tree species composition (beech/spruce), in comparison to original natural unmanaged fir-beech stands. Combination of geostratification and random sampling design was applied in the southern part of the Poľana Mts., Slovakia (about 1100 m a.s.l.). Subsequently, 153 research plots were established in homogenous habitat conditions in three stand types: secondary managed spruce and beech stands and a natural fir-beech forest. CCA analyses and permutation test were used to explain the herb layer variability. Spearman´s rank correlation coefficient was applied to find relationship between the herb layer and variables expressing tree influence. According to the results of CCA, herb layer was mostly influenced by dendrometric and litter characteristics of spruce; light conditions were not significant. Lower values of understorey diversity indices, pH of topsoil and litter were recorded in the spruce stands. Understorey of secondary beech stands and primeval fir-beech stands is more similar, but beech stands are rich in the spring geophytes occurrence.