Abstract:

Litter is very important for nutrient cycling in forest ecosystem. Studies on the amount of litter and its releasing regulation could provide the basis for management of Casuarina equisetifolia protective plantation, especially for management of soil system. The litter of C. equisetifolia protective plantation was collected with special collectors in Chihu Protection Forest Farm of Hui′an County,Fujian Province.The experiment for litter decomposition had been done over 3 years. The results showed that:(1)annual amount of litter of C. equisetifolia protective plantation was 13.973(20 a)and 12.385 t·hm^-2a^-1(7 a).(2)During the course of litter decomposing, the relationship between loss rate and decomposing time of litter mass could be expressed with equation W =-0.032 6t³+0.5465t²+2.1541t+0.865 7.(3)In the plantations with different ages, the content of nutrients was different. They were higher in plantation of 20 a than that of in plantation of 7 a. And there were obvious differences on content for different nutrient elements. (4)The annual amount of nutrients returned from litter was 250.24(7 a) and 280.25 kg·hm^-2a^-1(20 a). (5)According to estimation, the half-life of litter was about 1 year, and it should take about 4.4 years as 95% litter was decomposed.

Key words: Casuarina equisetifolia, Litter, Decomposition, Nutrient release