Foundation species and invasive species strongly influence community diversity and structure, but typically in different ways. However, when widespread invasive species provide novel habitat within a community, their net effect may depend on both the environment and community composition. Fouling communities in northern and southern California harbors were surveyed to determine whether there was variation between two locations in the percent cover of an invasive bryozoan, Watersipora subtorquata (d’Orbigny, 1852), and its relationship to community diversity and composition in these two environments. Diversity significantly differed between locations and had a location-dependent association with W. subtorquata abundance. Communities were significantly dissimilar between locations, and W. subtorquata abundance had the highest percent contribution to community dissimilarity when compared to other species in the community. These results suggest that invasive species may have both facilitative and inhibitive relationships with species in a community, but that the net balance of these interactions depends on both the environmental and community context.

中文翻译：

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侵入性苔藓虫对社区多样性和结构的影响在两个地方不同

基础物种和入侵物种强烈影响社区的多样性和结构，但通常以不同的方式。但是，当广泛的入侵物种在社区内提供新颖的栖息地时，其净效应可能取决于环境和社区组成。对加利福尼亚北部和南部港口的污损社区进行了调查，以确定在侵袭性的苔藓动物，Watersipora subtorquata（d'Orbigny，1852）的百分覆盖率中，两个位置之间是否存在差异，以及这两种环境下其与社区多样性和组成的关系。位置之间的多样性差异显着，并且与白僵菌的丰度有位置相关性。地点之间的社区明显不同，并且与群落中的其他物种相比，W。subtorquata的丰富度对群落异化的贡献率最高。这些结果表明，入侵物种与社区中的物种可能具有促进和抑制的关系，但是这些相互作用的净平衡取决于环境和社区环境。