Spatial heterogeneity in soil nutrient supply modulates nutrient and biomass responses to multiple global change drivers in model grassland communities

Changes in the atmospheric concentration of carbon dioxide ([CO2]), nutrient availability and biotic diversity are three major drivers of the ongoing global change impacting terrestrial ecosystems worldwide. While it is well established that soil nutrient heterogeneity exerts a strong influence on the development of plant individuals and communities, it is virtually unknown how nutrient heterogeneity and global change drivers interact to affect plant performance and ecosystem functioning. We conducted a microcosm experiment to evaluate the effect of simultaneous changes in [CO2], nutrient heterogeneity (NH), nutrient availability (NA) and species evenness on the biomass and nutrient uptake patterns of assemblages formed by Lolium perenne, Plantago lanceolata and Holcus lanatus. When the nutrients were heterogeneously supplied,assemblages exhibited precise root foraging patterns, and had higher above- and belowground biomass (average increases of 32% and 29% for above- and belowground bi...