Wood-decay fungi in hazel wood:: species richness correlated to stand age and dead wood features

The correlation between species richness of wood-decay fungi, stand age and dead wood features was investigated in eight hazel stands in south-east Sweden. Sampling of fruit-bodies was performed on fallen decomposing hazel stems and a total of 140 species were found, 60 ascomycetes (pyrenomycetes) and 80 basidiomycetes (Aphyllophorales). Total species richness correlated negatively with the age of stands, contrary to results in studies of other forest types. The reason for this is not known, but the possibility of competitive exclusion in old stands is discussed. In sites with a higher concentration of dead wood the number of species per stem was lower. The numbers of Red List species/indicator species were not correlated to stand age or wood decay. We suggest that old age of stands should be used with care as an evaluation criterion for hazel stands important for the protection of fungal biodiversity. (C) 2001 Elsevier Science Ltd. All rights reserved.