Résumé
Plant species diversity affects carbon and nutrient cycling during litter
decomposition, yet the generality of the direction of this effect and its
magnitude remain uncertain. With a meta-analysis including 65 field
studies across the Earth’s major forest ecosystems, we showed here that on
average decomposition was faster when litter was composed of more than one
species. These positive biodiversity effects were mostly driven by
temperate forests, but more variable in other forests. Litter mixture
effects emerged most strongly in early decomposition stages and were
related to divergence in litter quality. Litter diversity also accelerated
nitrogen, but not phosphorus release, potentially indicating a decoupling
of nitrogen and phosphorus cycling and perhaps a shift in ecosystem
nutrient limitation with changing biodiversity. Our findings demonstrate
the importance of litter diversity effects for carbon and nutrient
dynamics during decomposition, and show how these effects vary with litter
traits, decomposer complexity and forest characteristics.