Scaling coexistence and assemblage patterns of desert small mammals

RODRIGUEZ, DANIELA; OJEDA RICARDO ALBERTO

MAMMALIAN BIOLOGY

ELSEVIER GMBH

Año: 2013

1616-5047

Despite scaling biodiversity patterns have been lately recognized as a very important issue in the search of global processes, coexistence and assemblage patterns are typically approached at a single spatial scale. Here we examined coexistence and co-occurrence patterns of desert small mammal communities across different spatial scales in the search of general community patterns. For small spatial scales we sampled small mammals in Monte desert, (Argentina, South America) and for large spatial scales we used published papers from other worldwide deserts. To analyze species coexistence and co-occurrence patterns we used classic community estimators (Shannon, Richness), rank abundance curves and fitting distributions. To analyze assemblage patterns we evaluated nestedness across spatial scales and among deserts. Worldwide desert small mammal assemblages are characterized mainly by low species richness and high variation in species composition. On the central Monte Desert, there is a consistent assemblage pattern across spatial scales, with a generalist species being the most abundant and widely distributed, accompanied by other subordinate and more narrowly distributed species. All Monte Desert communities are significantly nested, and nestedness increased with scale from patch to regional. When comparing worldwide deserts, assemblage and coexistence patterns are similar despite differences in total richness and faunal singularity. Despite the degree of nestedness varies among worldwide deserts, all of them show a consistent nested pattern. Differences on the degree of nestedness could be a result of different regulating factors depending on the desert and scale. These results highlight the importance of including multiscale approaches when dealing with processes that structure desert communities.