Data from: Partitioning the effect of composition and diversity of tree communities on leaf litter decomposition and soil respiration

The decomposition of plant material is an important ecosystem process
influencing both carbon cycling and soil nutrient availability.
Quantifying how plant diversity affects decomposition is thus crucial for
predicting the effect of the global decline in plant diversity on
ecosystem functioning. Plant diversity could affect the decomposition
process both directly through the diversity of the litter, and/or
indirectly through the diversity of the host plant community and its
affect on the decomposition environment. Using a biodiversity experiment
with trees in which both functional and taxonomic diversity were
explicitly manipulated independently, we tested the effects of the
functional diversity and identity of the living trees separately and in
combination with the functional diversity and identity of the decomposing
litter on rates of litter decomposition and soil respiration. Plant
traits, predominantly leaf chemical and physical traits, were correlated
with both litter decomposition and soil respiration rates. Surface litter
decomposition, quantified by mass loss in litterbags, was best explained
by abundance-weighted mean trait values of tree species from which the
litter was assembled (functional identity). In contrast, soil respiration,
which includes decomposition of dissolved organic carbon and root
respiration, was best explained by the variance in trait values of the
host trees (functional diversity). This research provides insight into the
effect of loss of tree diversity in forests on soil processes. Such
understanding is essential to predicting changes in the global carbon
budget brought on by biodiversity loss.