Habitat edges alter arthropod community composition

• Published in: Landscape ecology Vol. 36; no. 10; pp. 2849 - 2861
• Main Authors: Wimp, Gina M., Murphy, Shannon M.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.10.2021; Springer Nature B.V
• Subjects: Arthropods; Biodiversity; Biodiversity loss; Biomedical and Life Sciences; Community composition; Composition; Divergence; Ecology; Edge effect; Environmental Management; Feeders; Habitat fragmentation; Habitats; Herbivores; Landscape Ecology; Landscape/Regional and Urban Planning; Life Sciences; Lumping; Natural enemies; Nature Conservation; Predators; Prey; Research Article; Salt marshes; Species composition; Species diversity; Species richness; Sustainable Development; Arthropod; Ecological boundary; Edge effects; Community; Diversity
• ISSN: 0921-2973; 1572-9761
• DOI: 10.1007/s10980-021-01288-6

Context Historically, habitat edges were thought to increase diversity by combining communities from two habitats, but empirical results are mixed. Variation in edge responses may be driven by lumping specialists and generalists with divergent responses. Objectives We examined arthropod communities associated with a habitat edge in an intertidal salt marsh in New Jersey. We predicted that herbivores, largely specialists, would decline along the habitat edge due to their failure to expand across the boundary, and specialist natural enemies should track prey. Generalists should be less impacted by the edge if they use resources from both sides. Thus, habitat edges should affect species composition more than species diversity. Methods We studied the edge responses of 115 arthropod species to the habitat edge formed between Spartina patens (SP) and Spartina alterniflora (SA) throughout the growing season. Results We found that the edge between SA and SP affected the abundance and composition of the associated arthropod community, but not species richness. Composition of herbivores, epigeic feeders, specialist natural enemies, and generalist predators shifted not only between SA and SP interiors, but also the edges. Compositional shifts were driven by dietary or habitat specialists. Conclusions We found that edges change community composition via divergent responses by species with different resource requirements. This change in composition is not between two disparate habitat types but two congeneric grass species. Our results demonstrate that biodiversity losses due to edge effects associated with habitat fragmentation will not be random but will be driven by specialization and resource use.