Data from: C, N, and P fertilization in an Amazonian rainforest support stoichiometric dissimilarity as a driver of litter diversity effects on decomposition

Plant leaf litter generally decomposes faster as a group of different
species than when individual species decompose alone, but underlying
mechanisms of these diversity effects remain poorly understood. Because
resource C : N : P stoichiometry (i.e. the ratios of these key elements)
exhibits strong control on consumers, we supposed that stoichiometric
dissimilarity of litter mixtures (i.e. the divergence in C : N : P ratios
among species) improves resource complementarity to decomposers leading to
faster mixture decomposition. We tested this hypothesis with: (i) a wide
range of leaf litter mixtures of neotropical tree species varying in C : N
: P dissimilarity, and (ii) a nutrient addition experiment (C, N and P) to
create stoichiometric similarity. Litter mixtures decomposed in the field
using two different types of litterbags allowing or preventing access to
soil fauna. Litter mixture mass loss was higher than expected from species
decomposing singly, especially in presence of soil fauna. With fauna,
synergistic litter mixture effects increased with increasing
stoichiometric dissimilarity of litter mixtures and this positive
relationship disappeared with fertilizer addition. Our results indicate
that litter stoichiometric dissimilarity drives mixture effects via the
nutritional requirements of soil fauna. Incorporating ecological
stoichiometry in biodiversity research allows refinement of the underlying
mechanisms of how changing biodiversity affects ecosystem functioning.