Grazing promotes dung beetle diversity in the xeric landscape of a Mexican Biosphere Reserve

Publication Type:Journal Article
Year of Publication:2007
Authors:J. R. Verdu, Moreno, C. E., Sanchez-Rojas, G., Numa, C., Galante, E., Halffter, G.
Journal:Biological Conservation
Keywords:Alpha and beta diversity, Aphodiinae, Barranca de Metztitlan, indicator species, Land mosaics, Scarabaeidae

We analyze the impact of grazing on dung beetle diversity at the Barranca de Metztitla ́ n Biosphere Reserve, a xeric ecosystem in central Mexico with a long history of use by humans. We compared the community structure, as well as the alpha and beta diversity between two cover conditions (open and closed vegetation) that represent the impact of grazing within a habitat, and between habitat types (submountainous and crassicaule scrublands). From 576 samples we collected 75,605 dung beetles belonging to 20 taxa. While mean species richness and diversity were different between habitat types, cumulative spe- cies richness was not. The effects of grazing on vegetation structure influenced the cumu- lative species richness and diversity of dung beetles in the submountainous scrubland, where grazing has created land mosaics of a grassland matrix with scrubland patches. This was not the case in the crassicaule scrubland where the impact of grazing is not as evident. Beta diversity significantly responds to the effects of grazing on habitat conditions. We dis- cuss the ecological factors that may promote these responses by landscape diversity com- ponents. We also identify the species that could act as useful indicators to monitor the effect of land management on biodiversity. Our results indicate cattle farming maintains a diversified land mosaic, and these areas support more diverse dung beetle ensembles than homogeneous areas of closed, shrubby vegetation cover. Thus, controlled grazing activity could certainly favour the conservation of dung beetle biodiversity and improve ecosystem functioning by maintaining dung decomposition rates.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith