The invasive crayfish Faxonius immunis is regarded as a threat to amphibians and macroinvertebrates in the Upper Rhine Valley, Germany, eradicating macrophytes and establishing high-density populations in stagnant waters. This study investigates the macroinvertebrate community structure of five conservation ponds south of Karlsruhe, Germany, to identify effects caused by this invasive crayfish. Two of the ponds had a high population density of F. immunis, two were expected to have lower crayfish densities as they had been habitat modified with gravelled water beds as a crayfish management approach, and one pond was known to be free of crayfish but contained fish. The macroinvertebrate communities were analyzed considering their species richness and composition. The relative density of F. immunis within the samples was regarded as a representative indicator for crayfish population density and tested for its influence on the ordination along with habitat composition and abiotic factors using distance-based redundancy analysis. F. immunis was identified as a driving factor of the macroinvertebrate communities of sampled ponds. Additionally, this study indicates that gravelling ground beds as a management method for invasive burrowing crayfish species does not significantly influence the community composition but can minimize indirect effects caused by F. immunis.

入侵小龙虾Faxonius immunis被认为是对德国莱茵河上游河谷的两栖动物和大型无脊椎动物的威胁，它可以消灭大型植物并在死水中建立高密度种群。本研究调查了德国卡尔斯鲁厄以南五个保护池塘的大型无脊椎动物群落结构，以确定这种入侵小龙虾造成的影响。其中两个池塘的F. immunis种群密度很高，预计两个小龙虾的密度较低，因为它们已通过砾石水床作为小龙虾管理方法进行了栖息地改造，而一个池塘已知没有小龙虾但含有鱼。考虑到它们的物种丰富度和组成，分析了大型无脊椎动物群落。样本中免疫梭菌的相对密度被视为小龙虾种群密度的代表性指标，并使用基于距离的冗余分析测试了其对排序的影响以及栖息地组成和非生物因素。F.免疫被确定为采样池塘大型无脊椎动物群落的驱动因素。此外，这项研究表明，砾石地床作为侵入性穴居小龙虾物种的管理方法不会显着影响群落组成，但可以最大限度地减少由F. immunis引起的间接影响。