Dung beetles and the conservation of diversity in an agricultural landscape with maize fields and Atlantic Forest remnants

Abstract Land use change is a global threat to biodiversity. Besides converting natural landscapes into monocultures, the use of genetically modified organisms is increasing, even though their effects on natural assemblages are still poorly known. The possible effects of transgenic crops on ecosystems can be studied using ecological indicators, such as dung beetles. We assessed the effect of creole, conventional, and transgenic maize crops on dung beetle assemblages in a landscape that also contained forest fragments in southern Brazil. We established 15 blocks, five on each type of maize fields. Each block consisted of a landscape with native forests and maize fields. A total of 2126 dung beetles were captured, belonging to 38 species. The forest-crop landscape associated with creole maize had a greater richness of dung beetle species. Conversely, an impoverished assemblage was detected in the transgenic maize crop landscape. The reduction of indicator insect diversity in landscapes influenced by transgenic crops suggests that the type of maize fields influences biodiversity conservation. In addition, the negative effects of transgenic crops went beyond maize fields, reaching native forest fragments adjacent to crops.