Landscape and management effects on structure and function of soil arthropod communities in winter wheat

This study evaluates the impact of agricultural management (organic vs. conventional) and landscape context on species richness and abundance of five soil arthropod taxa (ground beetles, spiders, springtails, millipedes, woodlice) and associated ecosystem functions (soil biological activity, weed seed predation, litter decomposition). A significant interaction between management type and landscape context was revealed in several cases. Activity density of millipedes and wood lice and species richness of ground beetles were higher in fields where local and regional management types were complementary, indicating a beneficial effect of environmental heterogeneity. In addition, seed predation on arable weeds was higher in organically than conventionally managed fields. It is concluded that the effect of agricultural management on soil arthropod biodiversity and functioning is often context dependent. The diversity of functionally important taxa such as ground beetles and decomposers may be enhanced by increasing environmental heterogeneity, a measure that is also beneficial for other components of agrobiodiversity. Thus, in a conventional agricultural context even managing only a fraction of fields organically may help to increase environmental heterogeneity and thereby promote soil arthropod diversity and the associated ecosystem functions.