Abstract

The structure and dynamics of mollusk communities, as well as environmental factors influencing them, were analyzed in small oxbow lakes of the forest-steppe zone (a case of the Khoper river valley, Penza region, Russian Federation). 19 species of mollusks were found in the studied water bodies. The oxbow lakes were characterized by relatively low alpha-diversity (number of species 4 ± 2) and relatively high beta-diversity (Jacquard index 0.26 ± 0.18), which is typical for floodplain ecosystems. Lake communities were dominated by Planorbis planorbis (40%), Lymnaea stagnalis (15%), Anisus spirorbis (14%), Lymnaea saridalensis (9%), Anisus vortex (8%). The results of our analysis showed that the group of factors that determined the type of water body (stability, light intensity, water temperature, oxygen concentrations) had the greatest impact on the structure of malacocenoses. The seasonal dynamics of mollusk communities was determined by the number of adjoining water bodies, water temperature, and dissolved oxygen concentrations. The number of adjoining oxbows was the major factor influencing mollusk species diversity, as well as the total number and biomass of mollusks. Oxbow isolation was favorable for mollusk communities. The factors influencing the highest number of mollusks species (seven) were the light intensity and the presence of fish. Other significant factors were the stability of lakes (shown for five species of mollusks), the number of adjoining oxbows and water transparency (four species). Aquatic vegetation positively correlated with the abundance of only one species—Anisus vortex. Our data suggest that the presence of fish could influence the abundance of Lymnaea saridalensis. The mollusks, in their turn, apparently, had a positive effect on the abundance of leeches in water bodies. Mollusk species most sensitive to the external factors were Lymnaea stagnalis, Lymnaea saridalensis, Aplexa turrita, Anisus spirorbis and Anisus leucostoma, most tolerant were Bathyomphalus crassus, Anisus vortex, Planorbis planorbis and Planorbarius corneus.

中文翻译：

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小牛b湖软体动物群落的结构，动力学及影响因素（科帕河州科珀河谷）

摘要

在森林草原区的小型牛弓湖中分析了软体动物群落的结构和动态，以及影响它们的环境因素（以俄罗斯联邦奔萨地区科珀河谷为例）。在研究的水体中发现了19种软体动物。oxbow湖泊的特征是阿尔法多样性较低（物种数为4±2），而β多样性较高（提花指数为0.26±0.18），这是洪泛区生态系统的典型特征。湖泊群落以Planorbis planorbis（40％），Lymnaea stagnalis（15％），Anisus spirorbis（14％），Lymnaea saridalensis（9％）和Anisus涡旋为主。（8％）。我们的分析结果表明，决定水体类型的因素（稳定性，光强度，水温，氧气浓度）对马拉科糖的结构影响最大。软体动物群落的季节动态取决于毗邻水体的数量，水温和溶解氧浓度。毗邻的牛的数量是影响软体动物物种多样性以及软体动物总数和生物量的主要因素。Oxbow隔离对软体动物群落有利。影响软体动物物种数量最多（七个）的因素是光照强度和鱼类的存在。其他重要因素是湖泊的稳定性（显示了五种软体动物），毗邻的牛的数量和水的透明度（四种）。水生植被与仅一种物种的丰度呈正相关，茴香涡。我们的数据表明，鱼的存在可能影响剑兰的丰度。显然，软体动物对水体中大量的水ches有积极作用。对外界因素最敏感的软体动物种类有：剑兰（Lymnaea stagnalis），剑兰（Lymnaea saridalensis），杜鹃花（Aplexa turrita），凤梨（Anisus spirorbis）和白蚁（Anisus leucostoma），最能耐受的是弯曲杆菌（Bathyomphalus crassus），凤梨（Anisus vortex），Planorbis planorbis和Planorbarius角膜。