Data from: Resource stoichiometry and availability modulate species richness and biomass of tropical litter macro-invertebrates

1. The high biodiversity and biomass of soil communities is crucial for
litter decomposition in terrestrial ecosystems such as tropical forests.
However, the leaf litter that these communities consume is of particularly
poor quality as indicated by elemental stoichiometry. The impact of
resource quantity, quality, and other habitat parameters on species
richness and biomass of consumer communities is often studied in
isolation, although much can be learned from simultaneously studying both
community characteristics. 2. Using a data set of 780 macro-invertebrate
consumer species across 32 sites in tropical lowland rainforest and
agricultural systems on Sumatra, Indonesia, we investigated the effects of
basal resource stoichiometry (C:X ratios of N, P, K, Ca, Mg, Na, S in
local leaf litter), litter mass (basal resource quantity and habitat
space), plant species richness (surrogate for litter habitat
heterogeneity), and soil pH (acidity) on consumer species richness and
biomass across different consumer groups (i.e., three feeding guilds and
ten selected taxonomic groups). 3. In order to distinguish the most
important predictors of consumer species richness and biomass, we applied
a standardised model averaging approach investigating the effects of basal
resource stoichiometry, litter mass, plant species richness, and soil pH
on both consumer community characteristics. This standardised approach
enabled us to identify differences and similarities in the magnitude and
importance of such effects on consumer species richness and biomass. 4.
Across consumer groups, we found litter mass to be the most important
predictor of both species richness and biomass. Resource stoichiometry had
a more pronounced impact on consumer species richness than on their
biomass. As expected, taxonomic groups differed in which resource and
habitat parameters (basal resource stoichiometry, litter mass, plant
species richness, and pH) were most important for modulating their
community characteristics. 5. The importance of litter mass for both
species richness and biomass indicates that these tropical consumers
strongly depend on habitat space and resource availability. Our study
supports previous theoretical work indicating that consumer species
richness is jointly influenced by resource availability and the balanced
supply of multiple chemical elements in their resources.