DOI: 10.5061/dryad.7hg8mp7
title: Data from: Traits including leaf dry matter content and leaf pH dominate over forest soil pH as drivers of litter decomposition among 60 species

description: 1. Soil pH varies by several units among ecosystems. While soil pH is
 known to be a key driver of plant species composition, we still have a
 poor understanding of how it affects carbon cycling processes. For
 instance, soil pH, or its associated chemistry in terms of base cations
 and organic acids, may affect decomposition rates of dead matter directly,
 by controlling decomposer composition and activity, and indirectly, by
 controlling the traits of the plant species and thereby the afterlife
 effects of those traits on litter decomposition. Leaf and litter pH may
 play a role in this control. Based on the very limited empirical data
 available, we hypothesized that variation in species traits including leaf
 (litter) pH, within and between ecosystems contrasting in soil pH, would
 have stronger effects on leaf litter decomposition rates than variation in
 soil chemistry would. 2. We tested this hypothesis by carrying out a
 ‘common garden’ litterbed experiment in subtropical SW China, in which
 leaf litters of the 30 predominant plant species from mid-successional
 forest on acidic sandstone (soil pH around 4.0) and calcareous soil (pH
 around 7.5) respectively, were incubated and their decomposition rates
 measured over two harvests in fourteen months, both in soil plus litter
 matrix from their ‘home’ forest and in those from the “away” forest. 3. We
 found that leaf (litter) trait variation among species and plant
 functional types, headed by species’ dry matter content but also including
 tissue pH, was the strongest driver of variation in leaf litter
 decomposition rates. Surprisingly however, while these effects of
 interspecific trait variation were very strong among species from the same
 site, there was no overall difference in litter decomposability between
 the species from the acidic versus calcareous site. Equally surprising was
 that this strong difference in pH of soil substrate plus litter matrix
 from an acidic sandstone site versus a calcareous karst site did not
 directly affect leaf litter decomposition rates across a given species
 set. 4. This first attempt to disentangle the multiple potential direct
 and indirect ways in which soil and leaf (litter) acidity might be related
 to litter decomposition rates, has important implications for our
 understanding of soil-plant feedbacks. Based on our forest-based study, we
 predict that soil-plant feedbacks via acidity are unlikely to be strong in
 ecosystems with wide-ranging species in terms of their leaf functional
 traits, including leaf pH.
description: species name leaf traits
 litter traits and mass loss data 20190618Data file containing
 species name, green leaf traits, leaf litter traits and litter mass loss
 measurements.species name plant traits and
 mass loss data 20190618.xlsxdata of chemical
 properties of soil and litter matrixData file containing
 chemical properties of litterbed soil and litter matrix from karst site
 and acidic sandstone site, at the beginning of the experiment and at the
 final harvest.