The effect of windthrow, wild fire, and management practices on epigeic Collembola in windthrown forest stands of the High Tatra Mts (Slovakia)

Epigeic communities of Collembola were studied after a windthrow in differently managed spruce forest stands in the High Tatras, Slovakia. Investigations were carried out in following treatments: reference forest stands (REF), windthrown stands left to natural regeneration (NEX), windthrown stands from which fallen wood had been extracted (EXT), and windthrown stands from which fallen wood had been removed and which had been affected by fire (FIR). A Kruskal-Wallis nonparametric ANOVA revealed significant differences of Collembola community composition and activity between the treatments studied, which was also further supported by the results from NMS ordination and cluster analysis using indicator species analysis. EXT stands had communities with remarkably high activity and diversity of Collembola, whereas FIR stands had low species richness and diversity indices compared to other treatments (REF, NEX, EXT). Windthrown stands had greater collembolan activity and diversity (NEX, EXT) than intact forest stands. However, forest specialists and bryophilous species were sensitive to forest clearing and fire disturbance and were replaced by xeroresistant and generalist species, or species preferring open habitats. The collembolan community most similar to that found in REF stands, in terms of community homogeneity and the magnitude of diversity indices, was found in NEX stands.