Drivers of soil respiration across a management intensity gradient in temperate grasslands under drought

Abstract Soil respiration is an important pathway of soil organic carbon losses in temperate grasslands; however, it rarely studied across broad management intensity gradients a landscape. Using the soda-lime method, we measured in-situ CO 2 efflux with single measurements long exposure time (i.e. 3 day long) 150 grasslands three German regions early summer 2018 and 2019. The ranged from unfertilized grazed to intensively fertilized frequently harvested ones. To assess effects grazing fertilization intensities plant diversity on efflux, used Structural Equation Modeling account for direct indirect through matter quantity quality. was suppressed by limited water availability caused naturally occurring droughts both study years. Under prevailing environmental conditions, intensity, biomass C:N ratio were not related efflux. In contrast, positively associated (standardized coefficient net effect: + 0.04 0.03 2019). This because led lower species richness and, thus, ratios soils, which higher (plant −0.09 −0.18 2019; −0.23 −0.33 Intensively managed have than extensively managed, species-rich even under extreme conditions natural droughts.