关键词: 森林凋落物, 化学组成, 凋落物分解速率, 红壤丘陵区

Abstract: A pot experiment with litter bags was conducted to study the relationships between the initial chemical composition of 8 kind forest leaf litters and 4 kind mixed leaf litters and their decomposition rates in degraded red soil hilly region of Southern China. Comparing with needle-leaf litters, broad-leaf litters had significantly higher contents of N, P, K, and Mg, but significantly lower contents of lignin and C. The decomposition rates of test litters were significantly positively correlated with the litters initial contents of N, P, K, and Mg (P<0.05), and negatively correlated with the initial contents of lignin and C as well as the lignin/N, lignin/P, and C/P ratios (P<0.05). The lignin content explained 54.3% of the variation in litter decomposition rates, being the key affecting factor. Litters C, N, and P contents also had close correlations with the decomposition rates, and together with lignin content, contributed 81.4% of the variation. It was suggested that in the process of vegetation restoration in degraded red soil hilly region of Southern China, introducing broad-1eaf trees with lower lignin and higher N and P contents would benefit the acceleration of forest litters decomposition and the restoration of soil fertility.

Key words: forest litter, chemical composition, litter decomposition rate, red soil hilly region of Southern China