A gradient analysis of communities of macrofungi and slime moulds on decaying beech logs

The occurrence of fungi and slime moulds on 70 decaying beech logs was surveyed based on the presence/absence of sporocarps. In total 277 species of fungi and 25 of slime moulds were recorded and summarised in a log/species datamatrix. The structure of the datamatrix was analysed using detrended correspondance analysis (DCA). The ecological nature of the gradients expressed by the first three DCA-axes was then investigated by environmental and log related variables. The first and strongest gradient corresponded to changes in the community development during the decay process. The second gradient was complex and corresponded to both decay rate and microclimatic stress. The third, rather weak, gradient was influenced by soil conditions. The gradients are discussed in a context of fungal ecological strategy theories. A model generalised from the community development on the studied logs is proposed.