来源地纬度和分解者类群对中国东部滨海湿地芦苇叶凋落物分解速率的影响

Effects of Origin Site Latitude and Decomposer Groups on Decomposition Rate of Phragmites australis Leaf Litter in Coastal Wetlands of Eastern China

为比较来自中国东部滨海湿地不同纬度的芦苇叶凋落物分解速率的差异,以及分解者类群对芦苇叶凋落物分解速率的影响,本研究将来自中国东部滨海湿地9个盐沼地区的芦苇叶凋落物在上海长江口盐沼进行同质园分解实验,同时使用3种不同的凋落物袋孔径(0.1mm、2mm、5mm)控制分解者类群.实验结果表明:(1)芦苇叶凋落物的来源地纬度和凋落物袋孔径均极显著地影响分解速率,但二者之间无显著交互效应.(2)来自不同纬度的芦苇叶凋落物可分解性不同,且随凋落物来源地纬度的增加而上升.结合芦苇叶凋落物质量指标的分析结果发现,芦苇叶凋落物分解速率差异可由凋落物磷、钙、钠、镁、总营养元素、半纤维素的含量,凋落物碳磷比等凋落物质量指标与其来源地纬度的相关关系解释.

To compare the decomposition rates of reed(Phragmites australis)leaf litter from coastal wetlands at different latitudes and determine the effect of decomposer groups,a common garden decomposition experiment was carried out in the Yangtze Estuary salt marsh of Shanghai.Reed leaf litter were collected from nine salt marshes in coastal wetlands of Eastern China.Three different mesh sizes(0.1 mm,2 mm,5 mm)of litter bag were used to control the decomposer groups.Our results show that:(1)the latitude of the reed leaf litter origin site and the mesh size of litter bag significantly affect the decomposition rate,but there is no significant interaction effect between two factors.(2)The decomposabilities of reed leaf litter from different latitudes are different,and increase with the increasing latitude of reed leaf litter origin sites.The difference of decomposition rate of reed leaf litter could be explained by the correlation between litter quality indexes such as P,Ca,Na,Mg,total nutrients,hemicellulose content and C/P ratio of litter and latitude of its origin.