Abstract
The biological invasion of aquatic ecosystems has negative effects on competition and predation. These ecological impacts on native communities may also affect two processes that are important in determining community structures, namely, the environmental and spatial processes. Here, we using lake fish community composition estimated through environmental DNA metabarcoding, we examined the effects of invasive species on the community structure determination processes in lakes. The objective was to describe the relationship between fish diversity and invasive species in lakes and to estimate the explanatory power of environmental factors with regard to variation in community composition among lakes using direct gradient analysis, i.e., distance-based redundancy analysis. Further, we employed variation partitioning to examine how the explanatory power of environmental factors and spatial structures for variation in community composition varied with the presence of invasive species. The environmental slope analysis showed that the explanatory power of environmental factors for variation in community composition among lakes was higher in communities without invasive species. A comparison of the relative importance of environmental factors and spatial structure in determining community composition between communities, excluding invasive species, and communities with invasive species showed that the relative importance of environmental factors was higher in communities without invasive species, highlighting the possibility of differences in dispersal abilities between native and invasive species.