Climate change does not alter land-use effects on soil fauna communities

Soil organisms are important drivers of the functioning of terrestrial ecosystems and co-determine how these ecosystems respond to human-induced changes in climate and land use. In the present study, we assessed the interacting effects of these two global change drivers on soil faunal communities. We carried out an experimental field study within the framework of the Global Change Experimental Facility (GCEF) manipulating (1) two climatic conditions (ambient vs. future) and (2) five land-use regimes (with two croplands: conventional farming and organic farming; and three grasslands: intensively-used meadow, extensively-used meadow and extensivelyused pasture). The future climate treatment is characterized by a slight increase of soil temperature (similar to 0.5 degrees C), whereas precipitation was strongly decreased during the summer (by similar to 20%) but moderately increased during spring and autumn (by similar to 10%). Soil fauna was sampled in two consecutive years in spring and autumn. Overall, future climate tented to have negative effects on soil fauna communities. For specific taxa, the detrimental effects of climate change were only evident for Isotomidae (Collembola) and Chilopoda. In general, soil faunal composition differed strongly between grasslands and croplands, with a higher number of macrofauna taxa and generally higher abundances of meso- and macrofauna in grasslands. However, land-use intensity within these land-use types had no further effect. Likewise, there were negligible interactive effects of climate and land use, and short-term effects of projected climate change on the community compositions of soil fauna were found to be more subtle than land-use effects. Land-use effects on soil fauna are therefore equally strong under ambient and future climatic conditions.