Data from: Multi-trophic β-diversity mediates the effect of environmental gradients on the turnover of multiple ecosystem functions

1. Much effort has been devoted to better understanding the effects of
environment and biodiversity on ecosystem functioning. However, few
studies have moved beyond measuring biodiversity as species richness of a
single group and/or focusing on a single ecosystem function. While there
is a growing recognition that along environmental gradients, the
compositional turnover of multiple trophic groups influences not only
productivity but multiple ecosystem functions, we do not know yet which
components of multi-trophic β-diversity influence which ecosystem
functions. 2. Here, we captured the biodiversity found in soils using
environmental DNA to study total soil multi-trophic β-diversity (between
all taxa regardless of their trophic group association), horizontal
β-diversities (β-diversities within trophic groups) and vertical
β-diversity (β-diversity across trophic groups) along a 1000-m elevational
gradient in the French Alps. Using path analyses, we quantified how these
β-diversity components mediate the effects of environmental turnover on
the turnover of multiple ecosystem functions (i.e. productivity,
N-cycling, N-leaching) and overall multifunctionality. 3. While we found a
strong direct effect of soil properties on the turnover of multiple
ecosystem functions, we also found an indirect effect of climate and soil
properties through multi-trophic β-diversity. More specifically, only
total multi-trophic β-diversity and the horizontal β-diversity of
saprophytic fungi were strongly related to the turnover of
multifunctionality and, to a lower extent, the turnover of productivity
and N-cycling. Our results suggest that decomposition processes and
resulting nutrient availability are key to understand how ecosystem
functions change along soil properties and climatic gradients in alpine
ecosystems. 4. Beyond alpine systems, our study stresses the paramount
importance of considering the mediating role of multi-trophic diversity in
environmental change impacts on different ecosystem functions and their
multifunctionality.