中国东部气候带凋落物分解特征——气候和基质质量的综合影响

Litter decomposition across climate zone in Eastern China:the integrated influence of climate and litter quality

凋落物分解是陆地生态系统物质循环和能量转换的主要途径。凋落物分解主要受到基质质量和气候因素多因子的综合影响。目前国内尚缺乏关于凋落物分解同气候因子和基质质量关系的多元统计和综合分析。应用分解袋法,对亚热带8个主要树种的凋落叶沿中国东部气候带5个地点历时2a的分解试验研究表明,年均降水量是影响中国东部凋落叶分解速率的首要气候因子,其次是实际蒸散和年均温度。凋落叶的初始N含量是决定分解快慢的首要基质因子,其次是P含量和Lignin∶N比和C∶N比。

Litter decomposition is a primary process of nutrient recycling and energy transiton in terrestrial ecosystems.Climate and litter quality are main factors controlling litter decomposition.Unfortunately,the relationship between litter decomposition and litter quality and the influence of climate variable on litter decomposition rate in China was poorly understood.The effects of climate and litter quality were investigated by conducting at 5 experimental sites,spanning 5 climatic regions along a temperature gradient across eastern China.We used litterbag method to determine annual decomposition rate of 8 species over a period of 2 years.The results indicated that mean annual precipitation（MAP） is a most important climatic variable affecting litter decomposition,following by mean annual temperature（MAT） and actual evapo-transpiration（AET）.The initial nitrogen（N） concentration of leaf litter were the most important litter quality variable,following by phosphorus（P） concentration,Lignin：N ratio and C∶N ratio.