Agricultural intensification and small mammal assemblages in agroecosystems of the Rolling Pampas, central Argentina

The aim of this paper is to describe variations in abundance, distribution and species richness of the small mammal assemblage under no tillage cropping in agroecosystems of the Rolling Pampas, and discuss how the changes associated with the introduction of this cropping system may have affected the community structure of small mammals in the rural landscape. Trapping was conducted during the summer between 2003 and 2005 in single-cropping soybean fields (n = 6), double-cropping soybean fields (n = 6), which were sown on wheat stubble and on a later date of sowing than single-cropping soybean, “clean” maize fields (n = 4), with low weed cover (≤20%), “weedy” maize fields (n = 3), with high weed cover (≥50%), and all the field edges (“borders”) surrounding these crop fields. Comparisons of small mammal abundance showed that borders and “weedy” maize fields had approximately a 12–18-fold higher trap success than single-cropping soybean and “clean” maize crop fields. However, no significant differences in small mammal trap success were found among crops, suggesting that rodents are looking for finer scale microhabitat features within the habitat rather than selecting a macrohabitat type based on crop identity.