Comparison of litter decomposing ability among diverse fungi in a cool temperate deciduous forest in Japan

Abstract

The litter decomposing ability of 79 fungal isolates (41 genera, 60 species) was assessed with the pure culture decomposition test. The isolates were collected qualitatively in a cool temperate deciduous forest in Japan during a 21-mo period. Loss of original weight of sterilized litter ranged from 0.1% to 57.6%. Six isolates in the Basidiomycota caused high weight losses ranging from 15.1% to 57.6%. Fourteen isolates in Xylaria and Geniculosporium (the Xylariaceae and its anamorph) also caused high weight losses ranging from 4.0% to 14.4%. Other isolates in the Ascomycota and associated anamorphs and in the Zygomycota caused low weight losses on mean. Six fungi in the Basidiomycota, and all in the Xylariaceae showed a bleaching activity of the litter and caused lignin and carbohydrate decomposition. Mean lignin/weight loss ratios (L/W) and lignin/carbohydrate loss ratios (L/C), were 0.9 and 0.7 for the Basidiomycota and 0.7 and 0.4 for the Xylariaceae, respectively. Significant differences were found in L/W and L/C between the two groups when the result of Xylaria sp. that showed marked delignification was excluded. These differences in lignin and carbohydrate utilization patterns are discussed in relation to the structural and the chemical properties of the decomposed litter and to the implications for organic chemical changes during litter decomposition processes.

• Basidiomycota
• beech leaf
• carbohydrate
• lignin
• Xylariaceae

We thank Dr. K. Kikuzawa for providing leaf litters used in the decomposition test; Dr. C. Tanaka for providing preliminary data on DNA analysis and for his valuable comments on fungal taxonomy; Drs. S. Tokumasu, E. Nagasawa, T. Hattori, T. Hosoya, and I. Tanaka, for their helpful identification of fungi; Dr. F. Hyodo for his critical reading of the manuscript. We acknowledge the helpful discussions of the members of the Laboratory of Forest Ecology, Kyoto University. This study was partly financially supported by a grant from the Japanese Ministry of Education, Culture and Sports relating to a JSPS Fellowship for Japanese Young Scientists (No. 4546).