A network approach for analyzing arthropod diversity and natural patches prioritization in a fragmented agroecosystem

Context: Natural habitat patches can mitigate the negative effects of agriculture on biodiversity. Local communities within natural patches are connected by dispersal and affected by multi-scale processes. Network theory enables to analyze metacommunity structures of different groups of species, such as common and rare species, and provides tools to prioritize the habitat patches. Objectives: We ask what are the local and landscape determinants of common and rare species diversities and whether the relative importance of the patches within the networks is similar for common and rare species. Methods: We sampled arthropod communities within natural patches in a fragmented agroecosystem of the Southern Judea Lowlands, Israel. We classified Coleoptera, Araneae, and Hemiptera taxa into common and rare species and constructed a metacommunity network for each group of species. Results: For Coleoptera and Hemiptera the association of patch connectivity is stronger with rare species than with common species diversities, suggesting that landscape determinants are more dominant in shaping rare than common species assemblages. Moreover, the spatial scale at which patch connectivity affects common and rare species differs between taxa. By comparing the relative importance of patches within the networks, we found a high correlation between common and rare species in each taxon. However, several patches diverge from this trend of similarity. Conclusions: This study emphasizes the importance of multi-scale determinants in shaping ecological communities at agroecosystems and stresses that common and rare species are distinctive groups of species that should receive explicit consideration in conservation management and planning.