岷江上游秋季浮游动物群落结构及水平分布特征

为了解岷江上游水电梯级河段浮游动物种类组成、密度和生物量及其多样性指数水平分布，于2011年秋季对岷江上游水电梯级浮游动物进行调查。结果显示，岷江上游秋季浮游动物有140种，平均密度3321.1 个/L，平均生物量1.2567 mg/L。紫坪铺水电站浮游动优势种比映秀镇以上引水式梯级的丰富，其密度是映秀镇以上河段的25倍，生物量是映秀镇以上河段143倍。依据浮游动物密度和生物量进行聚类分析，岷江上游25个站点分别聚为四大类。紫坪铺库区静缓流河段浮游动物多样性指数高于库区流水河段及映秀镇以上河段。岷江上游映秀镇以上河段和紫坪铺浮游动物群落特征差异较大，可能与生态环境有关。由于岷江上游生态环境破坏较为严重，其生态修复方案不断有人提出，本次岷江上游浮游动物群落特征调查为今后生态修复提供参考。

Autumn Zooplankton Community Structure and Horizontal Distribution in the Upper Minjiang River

The development of cascaded hydropower on the upper Minjiang River has resulted in serious ecological problems and attracted the attention of investigators. In this study, we investigated the zooplankton community in the upper Minjiang River, from Heishui River cove to Dujiangyan, a reach along which eight hydropower stations have been developed. From September 20 to October 20 of 2011, zooplankton were investigated at 25 sampling sites, focusing on species composition, density, biomass and the horizontal distribution of community diversity indices. A total of 140 zooplanktons species from 76 genera were identified, with dominance by protozoans (80 species, 40 genus), followed by rotifers (37 species, 20 genus), copepods (12 species, 6 genus) and cladocerans (11 species, 8 genus). Zooplankton community density and biomass averaged respectively, 3321.1 ind/L and 1.2567 mg/L in the upper Minjiang River during autumn. Zooplankton in the Zipingpu Hydropower Station Reservoir area are richer than in the upper reaches near Yingxiu Town, the reach where diversion-type cascaded hydropower stations were constructed. Zooplankton density and biomass were 25 times and 143 times higher in the Zipingpu area than the Yingxiu area. Cluster analysis, based on density and biomass, shows that the 25 study sites were clustered in four groups. Zooplankton diversity indices in the static reaches of Zipingpu Reservoir area were higher than in the flowing and upper reaches near Yingxiu Town. Community characteristics of zooplankton in the upper reaches of Yingxiu Town were noticeably different from those in the Zipingpu Reservoir area and result from differences in the ecological environment. This survey of zooplankton community provides a reference for future ecological restoration of the upper Minjiang River.