Relative importance of coarse and fine woody debris for the diversity of wood-inhabiting fungi in temperate broadleaf forests

Dead wood is considered important in forest conservation, but patterns of fungal diversity on dead wood have rarely been quantified. We investigated the relative importance of coarse (diameter > 10 cm) and fine woody debris (1-10 cm) for fungi in broadleaf forests in southern Sweden. The numbers of species per unit wood volume and per forest area were significantly higher for fine than for coarse woody debris for both ascomycetes and basidiomycetes. When the number of species was plotted against the number of records, coarse woody debris was more species rich than fine woody debris for a given number of basidiomycete records. Of the ascomycetes. 75% were found exclusively on fine woody debris (the corresponding proportion for basidiomycetes is 30%), 2% Were found exclusively on coarse woody debris (basidiomycetes 26%, and 23%,) of the species were found on both diameter classes (basidiomycetes 44%). We conclude that fine woody debris is important for diversity of wood-inhabiting fungi, especially ascomycctes. in this forest type. However, coarse woody debris must also be provided to insure the occurrence of many species of basidiomycetes. (C) 2003 Elsevier Ltd. All rights reserved.