Seasonal occurrence of macrofungi on denuded areas formed by thick volcanic deposition of the 2000 eruption on Mt. Usu, Hokkaido, Japan

Abstract

Seasonal occurrence of macrofungi was investigated on denuded areas formed by thick volcanic deposition of the 2000 eruption on Mt. Usu, Hokkaido, Japan, from 2004 to 2006. Fungal species richness increased from 9 in 2004 to 23 in 2006. Ectomycorrhizal fungal species were found at the first time in autumn in 2005 in the study site; 4 and 8 species were found in 2005 and 2006, respectively. The members of saprotrophic fungal species such as Psathyrellaceae and Strophariaceae found in 2004 were continuously found and their species richness were moderately increasing with the passage of the years. The numbers of macrofungal species disappeared were 2 and 1 during 2004-2005 and 2005-2006, respectively, whereas those of newly appeared were high: 9 and 8 during 2004-2005 and 2005-2006, respectively. The results indicate that macrofungi which utilize resources from plant residue buried underground and/or from regenerated seedlings through symbiotic associations propagated on the denuded areas, and the pattern of succession in macrofungal flora can be characterized as aggregation by the newly recruited species.