何凡　寇冀蒙　曾旖志　李婧　李勇　董雪　刘曼红

(东北林业大学，哈尔滨，150040)



帽儿山溪流中大型底栖动物的定殖对两种树叶分解速率的影响1)

何凡寇冀蒙曾旖志李婧李勇董雪刘曼红

(东北林业大学，哈尔滨，150040)

利用复合网袋法，对五角槭(Acermono)和稠李(Prunuspadus)两种树叶在帽儿山溪流中的分解速率进行了为期105 d的研究。结果表明：五角槭和稠李树叶在溪流中的分解速率常数(k)分别为0.024和0.030，符合指数衰减模型，均属于快速分解组。定殖在五角槭和稠李树叶上的大型底栖动物种类分别有30种和26种，均以蜉蝣目小蜉属(Ephemerellaspp.)为优势种。两种树叶上大型底栖动物的摄食功能群的多度和生物量无显著差异，而5次采样间的差异显著。定殖在五角槭树叶上的直接集食者比例最高(45.9%)，其次是捕食者(23.8%)和撕食者(22.4%)，最少的为过滤收集者，仅占4.6%；定殖在稠李树叶上直接集食者的比例最高(44.6%)，其次是捕食者(26.1%)和撕食者(25.4%)，过滤收集者仅占1.8%。说明在帽儿山溪流中，随着溪流增大，撕食者种类减少，直接集食者类群的密度对树叶分解速率具有显著影响。

五角槭；稠李；分解速率；大型底栖动物；功能摄食群

By composite mesh bag method, we studied the leaves decomposition process ofAcermonoandPrunuspadusfor 105 days in the streams of Maoer Mountain. The leaves decomposition rates (k) ofA.monoandP.paduswere 0.024 and 0.03, respectively, according with the declined exponential equation, belonging to the fast decomposition groups. The species numbers colonization benthic macro-invertebrate of theA.mono(30) leaf was higher than that ofP.padus(26) leaves, both with Ephemeroptera (Ephemerellaspp.) as dominant species. There were no significant differences between two species of the feeding function group of the benthic macro-invertebrate, but the difference was significant between 5 samplings. Between the colonized macro-invertebrate functional feeding groups, the direct gatherer inA.monowas dominant (45.9%), followed by the predator (23.8%), the shredder (22.4%), and the filter collector (4.6%). The direct gatherer inP.paduswas dominant (44.6%), followed by the predator (26.1%), the shredder (25.4%), and the filter collector (1.8%). In the stream of Maoer Mountain, with the increase of the stream, the shredder species decreased, and the direct gatherer group density had a significant effect on the leaf decomposition rate.

树叶凋落物的分解是溪流生态系统营养物质循环与能量流动的重要环节，异源有机物作为源头溪流中大型底栖动物的主要食物来源，其输入对于保持溪流中生物群落的完整性发挥着重要的作用[1-3]，分解过程主要分为3个阶段，即首先是在雨水的淋溶作用下导致树叶中的可溶性有机物及无机矿物质迅速流失的过程，随后微生物的附着、生长与繁殖活动使树叶内部结构发生改变而缓慢降解，以及由溪流里生存的大型底栖动物的定殖和取食活动造成树叶的机械破碎。……