Environmental heterogeneity modulates the effect of plant diversity on the spatial variability of grassland biomass

DALEO PEDRO; ALBERTI JUAN; CHANETON, ENRIQUE J.; IRIBARNE OSCAR; PASCUAL JESUS

NATURE COMMUNICATIONS

Springer

Año: 2023

2041-1723

Plant productivity varies due to environmental heterogeneity, and theory suggests that plantdiversity can reduce this variation. While there is strong evidence of diversity effects on temporalvariability of productivity, whether this mechanism extends to variability across space remainselusive. Here we determine the relationship between plant diversity and spatial variability ofproductivity in 83 grasslands, and quantify the effect of experimentally increased spatialheterogeneity in environmental conditions on this relationship. We found that communities withhigher plant species richness (alpha and gamma diversity) have lower spatial variability ofproductivity as reduced abundance of some species can be compensated for by increased abundance of other species. In contrast, high species dissimilarity among local communities (beta diversity) is positively associated with spatial variability of productivity, suggesting that changes in species composition can scale up to affect productivity. Experimentally increased spatial environmental heterogeneity weakens the effect of plant alpha and gamma diversity, and reveals that beta diversity can simultaneously decrease and increase spatial variability of productivity. Our findings unveil the generality of the diversity-stability theory across space, and suggest that reduced local diversity and biotic homogenization can affect the spatial reliability of key ecosystem functions.