阳澄湖大型底栖动物群落结构和空间分布特征

为了解阳澄湖大型底栖动物群落结构现状,于2014年7月—2015年7月对阳澄湖进行4次采样,14个采样点共采集底栖动物3门7纲35种,平均生物密度和生物量分别为340个/m~2、180.4 g/m~2。其中,主要优势种为铜锈环棱螺(Bellamya aeruginosa)、河蚬(Corbicula fluminea)、红裸须摇蚊(Propsilocerus akamusi)、中国长足摇蚊(Tanypus chinensis)和长角涵螺(Alocinma longicornis)。基于种群生物密度的聚类分析,14个采样点被分为3组,其生境特征分别对应于敞水区、水生植被区和人类活动频繁区。其中,河蚬主要分布在阳澄湖西湖区的敞水区;红裸须摇蚊、中国长足摇蚊和霍甫水丝蚓主要分布在中湖和东湖中北部的人类活动频繁区;铜锈环棱螺和长角涵螺主要分布在中湖和东湖的南部的水生植被区。各点位的生物多样性显示,敞水区采样点的多样性指数最高,其次是水生植被区和人为活动频繁区。研究结果表明,底质类型、水生植被分布和受污染状况是导致阳澄湖大型底栖动物空间分布差异的主要影响因素。

Community structure and spatial distribution of macrozoobenthos in Yangcheng Lake, China

In order to understand the community structure of macrozoobenthos in Yangcheng Lake, we surveyed the macrozoobenthos of Yangcheng Lake four times during the period from July 2014 to July 2015. A total of 35 macroinvertebrate species from three classes and seven phyla were collected at 14 sampling sites. The mean abundance and biomass of macrozoobenthos were 340 ind/m² and 180. 4 g/m², respectively. The dominant species of Yangcheng Lake were Bellamya aeruginosa, Corbicula fluminea, Propsilocerus akamusi, Tanypus chinensis, and Alocinma longicornis. Based on clustering analysis, the 14 sites were divided into three groups. Their habitat features corresponded to open water areas, aquatic vegetation areas, and areas with frequent human activity, respectively. Corbicula fluminea was mainly distributed in open water areas in the western part of the lake. Propsilocerus akamusi, Tanypus chinensis, and Limnodrilus hoffmeisteri were mainly distributed in the areas with frequent human activities in the middle of the lake and the north central area of the eastern part of the lake. Bellamya aeruginosa and alocinma longicornis were mainly distributed in the aquatic vegetation areas in the middle of the lake and the southern area of the eastern part of the lake. The biodiversity was greatest at sites in the open water areas, followed by the aquatic vegetation areas and areas with frequent human activities. The study results show that substate types, aquatic vegetation, and pollution conditions are the main factors causing the difference in spatial distribution of macrozoobenthos in Yangcheng Lake.