环境因素对黑水滩河上游河段潜流层大型无脊椎动物群落的影响

Influence of environmental factors on hyporheic macroinvertebrate assemblage in the upper reaches of Heishuitan River

在黑水滩河上游河段选取5个断面调查了潜流层大型无脊椎动物及其生境特征,研究微观尺度环境因素对潜流层大型无脊椎动物群落组成及分布的影响。结果表明:调查河段共发现大型无脊椎动物29种,其中水生昆虫种类最多;各断面大型无脊椎动物的密度、生物量和丰富度均随着潜流层深度的增加而降低;潜流层沉积物的中值粒径、垂向水力梯度和垂向渗透系数是影响大型无脊椎动物组成和分布的主要因素,其中最重要的是中值粒径。潜流层无脊椎动物群落变化也可能受到食物源和生物之间相互作用等因素的影响,所有这些因素共同形成了一个复杂的自然过滤系统,控制着潜流层无脊椎动物的群落结构和空间分布。

In order to study the influence of environmental factors on community structure and distribution of hyporheic macroinvertebrates at a micro-scale,we chose five sites to investigate hyporheic macroinvertebrates and habitat characteristics in the upper reaches of Heishuitan River.Our results indicated that a total of 29 species of macroinvertebrates were collected,and aquatic insects were the dominant group. The density,biomass and richness of macroinvertebrates decreased with the bed depth. The composition and distribution of the hyporheic macroinvertebrates were determined by median diameter（ D50） of sediments,vertical hydrological gradient（ VHG）and vertical hydraulic conductivity（ Kv）,and D50 was the most important factor. Besides,the food sources and the interactions of macroinvertebrates may also play important roles in affecting community structure of hyporheic macroinvertebrates. All of these factors formed a complex natural filter to control the composition and distribution of the hyporheic macroinvertebrates.