Decomposing ability of filamentous fungi on litter is involved in a subtropical mixed forest

Abstract

The abilities of 10 filamentous fungi, isolated from Pinus massoniana-Liquidambar formasana mixed forest (PLF), to decompose fresh, fallen needle and leaf litter were studied with pure-culture tests. The results showed that all fungi except Mucor sp. and Chaetomium bostrychodes could drive mass loss of L. formasana leaf litter significantly more than that of P. massoniasa. Mass loss of litter in the first 5 wk of the study was higher than that in the last 5 wk. The decomposition rate was negatively correlated to the original lignin/nitrogen (L/N) and carbohydrate/nitrogen (C/N) ratios. Based on the mass loss of litter (W), carbohydrate (C) and lignin (L), and the mutual relationship between L/W and L/C ratio, we concluded that Mucor sp. had the lowest decomposing ability on P. Massoniana and L. formasana litter and that it could not use lignin. The Chaetomium bostrychodes were lignin and carbohydrate decomposers but preferred lignin. Trichoderma sp. 1 and Cladosporium herbarum were carbohydrate-decomposing fungi. Trichoderma sp. 2, Aspergillus fumigatus, Alternaria sp. and Penicillium sp. 2 were able to decompose lignin and carbohydrate but preferred carbohydrate and had high ability to decompose litter. Aspergillus niger and Penicillium sp. 1 were able to decompose lignin and carbohydrate only in the early phase of the study. The decomposing ability of fungi varied even within genus. No direct relationship was found between the frequency of isolation and the decomposing ability of fungi.

• carbohydrate
• cellulose
• decomposing ability
• fungi
• leaf litter
• lignin

This study was supported by National Science Foundation of China (30870419; 30571493; 30710103), Harbin Science Foundation for Outstanding Scholarship (2007RFXXN-047), Chinese National Programs for Science and Technology Development (2006BAD08A11105) and the National Natural Science Foundation of Heilongjiang Province (C2007-08).