柳杉凋落物在中国亚热带和热带的分解

Decomposition of Cryptomeria fortunei leaf litter in subtropical and tropical China

柳杉(Cryptomeria fortunei)为我国特有种,具有很高的经济价值,而且在吸收二氧化碳和净化空气方面具有重要作用。为探究全球气候变暖对森林凋落物分解速率的影响,分别在中亚热带的千岛湖、南亚热带的鼎湖山和热带的尖峰岭,用分解袋法对柳杉凋落物进行分解实验,3个实验样地的主要差异为温度。结果表明:凋落物在3个样地的分解速率顺序为尖峰岭、鼎湖山、千岛湖,且不同样地之间的分解速率具有显著差异(P<0.01)。在千岛湖样地分解速率常数k值与初始C/N呈显著相关(P<0.05);在鼎湖山样地分解速率常数k值与初始碳含量呈极显著相关(P<0.01);在尖峰岭样地,凋落物的分解速率常数k值与凋落物各初始化学元素含量相关性均不显著,推测可能是气候起主要作用。

Cryptomeria fortune is a special coniferous species with very high economic value and plays an important role in carbon sequestration and atmospheric purification in China.In order to explore the effects of climate warming on the litter decomposition,the decomposition experiment of Cryptomeria fortune leaf litter in three sites（Qiandaohu in Zhejiang Province,Dinghushan in Guangdong Province,and in Jianfengling in Hainan Province）were conducted along with climate gradient,using litterbags method.The sites represented the mid-subtropical area,southern-subtropical area,and tropic area,represently,they are with different temperature.The results indicated that significant difference（P〈0.01）was found for litter decomposition rates in three sites,and litter decomposition rate was ranked in the order of JianfenglingDinghushanQiandaohu along with the gradient.We also found that annual decomposition rates of leaf litter in Qiandaohu was significantly correlated with the initial C/N（P〈0.05）,it was significantly correlated the initial nitrogen content in Dinghushan（P〈0.01）.Insignificant relationship between decomposition rate and litter substrate was found in Jianfengling site.The result approved that the influence of climatic gradient on litter decomposition is important.