Diversity of filamentous fungi in organic layers of two forests in Zijin Mountain

A study was conducted to evaluate the cultivable filamentous fungal diversity in organic layers (L, F, and H layers) and A1 layer of two main forest types,Pinus massoniana andLiguidambar formasana mixed forest andQuercus variabilis forest, in Zijin Mountain(32°5′ N, 118°48′ E), Nanjing, China. A total of 67 taxa comprising 56 Deuteromycetes, 3 Zygomycetes, 5 Ascomycetes and 3 unidentified fungi were recognized from samples from the forest floor of the two forest types. The most abundant group was Deuteromycetes. The dominant genera in both forests wereAlternaria sp.,Aspergillus sp.,Cladosporium sp.,Mucor sp.,Penicillium sp.,Rhizopus sp.,Gliocladium sp. andTrichoderma spp. The fungal diversity was higher in the mixed forest than that inQ. variabilis forest. For both forest types, the maximum fungal diversity was found in layer F and there existed significantly different in fungal diversity between layer F and layer L. In the mixed forest, richness of fungi isolated from needle litter (P. massoniana) was lower than that from leaf litter (L. formasana). The richness of fungi from needle litter increased with the increase of forest floor depth, but for leaf litter, the fungal diversity decreased with the depth of forest floor. The co-species of fungi from the two forest types, as well as from two kinds of litters in mixed forest, increased with the depth of the forest floor. The succession of fungi along with the process of decomposition was discussed here. The results also showed that litter quality was a critical factor affecting fungal diversity.