高寒湿地植物残体降解的动态分析

用尼龙网袋法测定了高寒湿地植物残体的降解动态.结果表明,立枯体和草根的分解率均显示出明显的季节变化,主要失重发生在样品埋放初期和植物生长季节,非生长季节和样品埋放后期分解作用很弱.不同月份植物残体的分解率呈不同程度的差异性,在立枯体埋放的第1个月,沼泽草甸的分解率略高于矮嵩草草甸,以后两草甸的分解率趋于相当;矮嵩草草根在沼泽草甸的分解率显著高于在矮嵩草草甸的分解率.相关分析表明植物残体的降解与土壤微生物群落、土壤温度、水分都有明显的相关关系,植物残体的化学品质也是影响分解率的重要因素.

Analysis of plant residue decomposition dynamics in alpine swamp meadow

The plant residue decomposition in alpine swamp soil was studied by using a mesh-bag method at the Haibei Research Station from September 2000 to August 2002. The standing dead matter and root decomposition rates showed clear seasonal change. The most mass loss occurred in the initial stage after sample burial and during the plant-growing season. There was almost no decomposition during the winter freezing season and in the late stage after sample burial. The decomposition rates of plant residue in different months showed significant differences. In the first month after samples of standing dead matter were buried, the decomposition rates of plant residue in swamp meadow were higher than in Kobresia humilis meadow, but afterwards the rates were similar. The decomposition rate of K. humilis roots buried in swamp meadow soil was significantly higher than when buried in K. humilis meadow soil (P<0.01). The correlation analysis showed that the decomposition rates of plant residue correlated with soil microorganism communities, soil temperature and soil water content. The chemical character of the plant residue is also a key factor influencing the decomposition rate.