Abstract
Stream ecosystems are spatially heterogeneous environments due to the habitat diversity that define different microhabitat patches within a single area. Despite the influence of habitat heterogeneity on the biodiversity of insect community, little is known about how habitat heterogeneity governs species coexistence and community assembly. Here, we address the question if habitat heterogeneity may drive changes in community composition of the stonefly (Plecoptera, Insecta) community in different sampling locations, by assessing the relative role of the habitats that explain beta biodiversity patterns (spatial structure) and evolutionary processes (phylogenetic signal) in structuring communities.
We sampled across seven habitats types among 20 sampling sites in Alpine rivers, and we used mitochondrial DNA, cox1, and nuclear DNA, ITS, genetic markers on 21 stoneflies morpho-species to estimate putative DNA-species by General Mixed Yule Coalescent model (GMYC). With the use of putative DNA-species, we first analyzed the patterns of variation of DNA-species richness, composition, and diversity of stonefly community assessing their habitat correlates. Then, we assessed through a phylogenetic clustered pattern if DNA-species with similar physiological requirements co-occur due to environmental filtering.
Based on 52 putative DNA-species, we found that corridors contributed to DNA-species richness where the meandering corridor section displayed the highest contribution. While, habitats contributed to DNA-species diversity, where glide, riffle, and pool influenced the spatial structure of the stonefly community possible owed to the high species turnover observed.
Among the habitats, pool showed a significant phylogenetic clustering, suggesting evolutionary adaptation and strong habitat filtering. This pattern of community phylogenetic structure could have resulted from the long-term stability of the habitat and physiological requirements of the species that cohabitate.
Our study shows the importance of different habitats on the spatial and phylogenetic structure of stonefly community assemblies and sheds light on the habitat-specific diversity that may help improve conservation practices.
