Influence of agricultural factors on weed, carabid and bird richness in a Mediterranean cereal cropping system

Using a multimodel inference approach, the most relevant field-level and landscape context factors explaining the simultaneous variability of bird, carabid and weed species richness were identified and interpreted in a low-intensity cereal farming system in central Spain. Weed species richness was negatively influenced by sowing density, herbicides and surrounding mean field size. Carabid species richness was negatively related to applied nitrogen, but positively to surrounding land cover diversity and applied phosphorous. Bird species richness was positively influenced by focal field size, but negatively by surrounding land cover diversity, sowing density and amount of potassium applied. Although all three biological groups reflected the influence of intensification factors operating at different spatial scales, the most relevant factors were specific to each particular group. These results have implications in terms of the selection of targets for agri-environmental measures aiming at reversing the impacts of agricultural intensification on biodiversity.