山地河流潜流层大型无脊椎动物群落组成及分布

Distribution and species composition of hyporheic macroinvertebrates in a mountain stream

潜流层大型无脊椎动物是河流生态系统重要的组成部分.2013年8月（夏季）、12月（冬季）和2014年4月（春季）,在黑水滩河上游河段,采用人工基质法调查潜流层大型无脊椎动物.结果表明：3个季节共采集大型无脊椎动物27种,其中夏季22种、冬季和春季各16种,各季节水生昆虫种类所占比例均较高,分别为81.8%、75.0%和62.5%;夏季群落密度显著低于冬季和春季,春季最高;冬季群落生物量显著高于夏季和春季,夏季最低;3个季节群落的物种丰富度指数、Shannon多样性指数和Pielou均匀度指数均没有显著性差异.空间分布上,大型无脊椎动物的密度和丰富度均随潜流层深度增加而呈现降低的趋势,大多数个体均分布在0-20 cm深度.群落以滤食者和收集者组成的集食者为绝对优势功能群.动物的相互作用、生活史策略和潜流层的理化条件影响着潜流层大型无脊椎动物的群落结构和时空分布.

Hyporheic macroinvertebrates are an important component of stream ecosystem. The composition and distribution of the hyporheic macroinvertebrates were investigated using artificial substrates in the upper reaches of Heishuitan River in August,December 2013 and April 2014. The results indicated that a total of 27 microinvertbrate species were identified in all three seasons. In summer,22 species were identified,accounting for 81.8% of aquatic insects. 16 species were identified both in winter and spring,accounting for 75.0% and 62.5% of aquatic insects,respectively.The density of macroinvertebrate assemblage was significantly lower in summer than in winter and spring,and was the highest in spring. The biomass of macroinvertebrate assemblage was significantly higher in winter than in summer and spring,and was the lowest in summer. Species richness,Shannon index and Pielou index all had no significant difference among the three seasons. The density and richness of macroinvertebrates decreased with bed depth,and the maximum invertebrate density was found within the top 20 cm of the stream bed. Collector-filterer and collector-gatherer were the dominant functional feeding group in all three seasons. The community structure and temporal-spatial distribution of macroinvertebrates were determined by interactions and life history strategy of macroinvertebrates,and physical-chemical factors of hyporheic zone.