香溪河流域河流中树叶分解速率的比较研究

Comparison of leaf decomposing rate in a headwater stream in Xiangxi River catchment.

应用分解网袋法 ,对神农架地区的 1条 1级支流河岸林 4种乔木树种的树叶凋落物进行了连续90d的分解研究 .结果表明 ,不同树种树叶干重的损失程度不一样 .华西枫杨、连香树树叶干重损失达77%、71%;而米心水青冈和多脉青冈树叶干重损失为 43%和 42 %.利用指数方程Wt=W0 e-kt对 4种树叶凋落物的干重损失过程进行拟合 ,效果较好 .根据分解速率值的大小 ,将华西枫杨、连香树划分为快组 ,米心水青冈和多脉青冈为中等组 .收集到无脊椎动物 2 2种 ,分属于 3纲、6目、2 1科 .在不同时期 ,不同植物种类叶袋中无脊椎动物的数量各不相同 .可能与树叶中营养成分的不同有关 .在早期分解阶段 ,无脊椎动物数量较多 ,个体体长较短 ;在分解中后期 ,个体绝对数量减少 ,但个体体长增加 .

With the litterbag method,the decomposition of leaf of 4 tree species growing in riparian forest in a headwater stream was inestigated in 90 d consecutively in Xangxi River catchment.The results showed that the loss rate of dry weight of leaf differed among 4 species.The loss rate of dry weight of Pterocarya insignis and Cercidiphyllum japonicum was 77% and 71%,and shat of Fagus engleriana and Cyclobalanopsis multinervis was 43% and 42%.Using exponential equation,the loss process of dry weight of leaf was modeled.According to the value of constant k,4 species could be divide into to fast group and medium group.The invertebrate was also collected,and there were 22 species,belong to 3 classes,6 orders,and 21 families.The quantity of invertebrate differed in each tree species litterbag and different periods.The invertebrate was rich in number and small in body during early time of leaf decomposing,and it was less in number and big in body during middle and late time of decomposing.