Geographic patterns of ground-dwelling arthropods across an ecoregional transition in the North American Southwest

TitleGeographic patterns of ground-dwelling arthropods across an ecoregional transition in the North American Southwest
Publication TypeJournal Article
Year of Publication2008
AuthorsLightfoot DC, Brantley S.L., Allen C.D.
JournalWestern North American Naturalist
Date Published2008
Accession NumberJRN00501
Call Number00920
Keywordsarthropod, biogeography, arthropod, ecotones, arthropod, geographic distribution, arthropod, ground-dwelling, arthropod, species richness, article, cricket, geographic distribution, grasshopper, geographic distribution, journal, spider, geographic distribution

We examined the biogeographic patterns of ground-dwelling arthropod communities across a heterogeneous semiarid region of the Southern Rio Grande Rift Valley of New Mexico. Our 3 sites included portions of 5 ecoregions, with the middle site a transition area where all ecoregions converged. We addressed the following 3 questions: (1) Do the species assemblage patterns for ground arthropods across habitats and sites conform to recognized ecoregions? (2) Are arthropod assemblages in distinct vegetation-defined habitats within an ecoregion more similar to each other or to assemblages in similar vegetation-defined habitats in other ecoregions? (3) Is there a detectable edge effect with increased arthropod diversity in the area of converging ecoregions? We encountered 442 target arthropod species from pitfall traps operating continuously for 7 years over a series of different habitats at each of the 3 sites. We examined geographic distributions of spider and cricket/grasshopper species in detail, and they showed affinities for different ecoregions, respectively. Each habitat within a study site supported a unique overall arthropod assemblage; nevertheless, different habitats at the same site were more similar to each other than they were to similar habitats at other sites. Overall arthropod species richness was greatest in the area where all 5 ecoregions converged. Arthropod species and their geographic distributions are poorly known relative to vascular plants and vertebrate animals. Findings from this research indicate that ecoregional classification is a useful tool for understanding biogeographic patterns among arthropods.

Reprint Edition (04/03/2008)