武夷山黄山松凋落叶在不同植物群落中的分解动态

Leaf litter (Pinus tanwanensi) decomposition in four plant communities at different altitude in Wuyi Mountain

用分解网袋和萘排除两种方法,研究土壤动物对凋落叶的分解效应,并分析了随海拔梯度变化黄山松凋落叶的分解动态。结果表明:在1a的分解时间内,常绿阔叶林样地上未用萘处理的大孔分解袋内凋落叶的分解率为中孔的1.33倍、小孔的1.54倍;高山草甸上未用萘处理的大孔分解袋内凋落叶的分解率为中孔的1.12倍、小孔的1.22倍;土壤动物对凋落叶的分解有显著的促进作用,常绿阔叶林样地上土壤动物贡献率为32%,而高山草甸土壤动物贡献率仅为5%,土壤动物作用的骤减是高山草甸凋落叶分解速率较低的重要原因之一。随着海拔升高,温度降低,土壤动物类群数减少,活性下降,凋落叶的分解速率降低。凋落叶的分解受凋落叶基质质量、土壤动物类群、数量以及样地温度、降雨量等综合因素的影响。

Soil fauna plays an important role in plant litter decomposition. To examine the decomposition mechanism of coniferous leaf litter along the elevation gradient in Wuyi Mountain,we applied litterbag method and naphthalene treatment to study the decomposition function of soil fauna and dynamic decomposition of coniferous leaf litter along altitude from April,2007 to April,2008. The results showed that the situation of decomposition rates of coniferous leaf litter in different kinds of bags without naphthalene treatment in evergreen broadleaf forest is that the rate of coarse size bags is 1. 33 times more than that of medium size bags,and 1. 54 times more than that of fine size bags. In alpine meadow,the coniferous leaf litter decomposition rate of coarse size bags is 1. 12 times more than that of medium size bags,and 1. 22 times more than that of fine size bags. Soil fauna plays a significant role in plant litter decomposition. The contribution rate of soil fauna in evergreen broadleaf forest is 32 % ,and it is only 5 % in alpine meadow. One of the important reasons about the low decomposition rate is that the decreased function of soil fauna. With the increase of the altitude and the decrease of temperature,the kind of soil fauna is decreasing,the ability of soil fauna’s act is turning low,and the decomposition rate of the coniferous leaf litter is turning low. The decomposition process of leaf litter was synthetically influenced by litter quality,the kinds and quantity of soil fauna,temperature and rainfall.