应用分解袋法研究了三江平原小叶章湿地枯落物的分解失重及其主要营养元素的变化动态。结果表明,小叶章枯落物的年分解速率为0.257,二次指数模型:Wt/W0=0.0399e-0.545t+0.9601e0.018t(R2=0.945)能更好地描述其分解失重动态。分解过程中,C、N、P、Ca的积累系数(NAI)<100%(P<0.05),元素发生了净释放;K、Na的NAI>100%(P<0.05),元素发生了净积累;Mg、Mn、Fe的NAI值与100%无显著差异(P>0.05),元素既有释放又有积累。分解16个月后,小叶章枯落物各元素总体释放率的大小顺序为:Fe>P>Ca>N>C>Mg>Mn>K>Na,而相应元素的释放量分别为:0.106、0.147、0.971、0.568、65.37、-0.017、-0.114、-0.209和-0.125 g.m-2。
With litterbag method,this paper studied the mass loss of Deyeuxia angustifolia litter during 16 months of its decomposition in Sanjiang Plain,and the dynamics of the major elements in the litter.The results showed that the annual decomposition rate of D.angustifolia litter was 0.257,and the double exponential model W_t/W_0=0.0399e~(-0.545t)+0.9601e~(0.018t)(R~2=0.945) could describe the mass loss more effectively.During decomposition,the element accumulation index(NAI) values of C,N,P and Ca were significa...