江西仙女湖流域大型底栖动物群落结构及水质评价

COMMUNITY STRUCTURE OF MACROZOOBENTHOS IN XIANNV LAKE BASIN AND ASSESSMENT OF ITS WATER

以典型的亚热带大型山地丘陵湖泊——江西省仙女湖研究为例,2014-2015年每月对仙女湖湖区及主要入湖河流进行了大型底栖动物群落的周年动态研究。经鉴定得底栖动物111种,隶属3门53科77属。其中软体动物40种,节肢动物61种,环节动物10种。优势种为中华颤蚓、梨形环棱螺、河蚬、锯齿新米虾、羽摇蚊、粗腹摇蚊属、前突摇蚊属、霍甫水丝蚓。仙女湖大型底栖动物年平息栖息密度为346 ind./m2,年平均生物量为54.26 g/m2;不同区域和季节底栖动物的栖息密度与生物量有显著差异（P〈0.05）,河流型生境R2年平均栖息密度最大,为722 ind./m2。湖泊型生境L4年平均栖息密度最小,为251 ind./m2。1月的平均栖息密度最高,为567 ind./m2,5月平均栖息密度最低,为163 ind./m2。用辛普森多样性指数对不同区域水质进行评价,结果表明,入湖河流和钤阳湖为轻度污染,舞龙湖为中度污染。系统聚类和MDS排序分析表明,大型底栖动物的分布具有环境空间异质性,可以划分为2个群落。

This study is aimed to investigate the community structure of macrozoobenthos and assess the water quality status of Lake Xiannv in Jiangxi, one of the Chinese lakes with good water quality, and to provide the reference for the aquatic environmental protection in this important ecological function zone. The annual dynamics of macrozoobenthos community was studied in the Xiannv Lake and the main inflowing rivers（Yuanhe River, Yangqiao River, Xinzhi River,Yuankeng Stream and Jiulong River） from May, 2014 to May, 2015. In total, 116 taxa belonging to 3 phyla, 55 families and 78 genera were identified. Totally, 43 taxa belong to mollusca, 62 taxa belong to arthropoda, and 10 taxa belong to annelida. The dominant species were Tubifex sinicus, Bellamya purificata, Corbicula fluminea, Neocaridina denticulate,Tendipesplumosus sp., Pelopia sp., Procladius sp. and Limnodrilus hoffmeisteri. The annual average density and biomass of macrozoobenthos was 346 ind./m^2 and 54.26 g/m^2 in Lake Xiannv, respectively. There was a significant difference in density and biomass among both different seasons and areas（P〈0.05）. Using Simpson＇s diversity index, water quality in different areas was assessed, which showed that inflowing rivers and Lake Qianyang, the upstream lake zone of Xiannv Lake, was slightly polluted and Lake Wulong, the downstream one, was moderately polluted. The results of cluster analysis and MDS showed that the distribution of macrobenthos had obvious environment and spatial heterogeneity, and 2 station groups were divided