DOI: 10.5061/dryad.h44j0zpsv
title: Data from: Intraspecific leaf trait variation mediates edge effects on litter decomposition rate in fragmented forests

description: There is strong trait dependence in species-level responses to
 environmental change and their cascading effects on ecosystem functioning.
 However, there is little understanding of whether intraspecific trait
 variation (ITV) can also be an important mechanism mediating environmental
 effects on ecosystem functioning. This is surprising, given that global
 change processes such as habitat fragmentation and the creation of forest
 edges drive strong trait shifts within species. On 20 islands in the
 Thousand Island Lake, China, we quantified intraspecific leaf trait shifts
 of a widely distributed shrub species, Vaccinium carlesii, in response to
 habitat fragmentation. Using a reciprocal transplant decomposition
 experiment between forest edge and interior on 11 islands with varying
 areas, we disentangled the relative effects of intraspecific leaf trait
 variation vs. altered environmental conditions on leaf decomposition rates
 in forest fragments. We found strong intraspecific variation in leaf
 traits in response to edge effects, with a shift towards recalcitrant
 leaves with low specific leaf area and high leaf dry matter content from
 forest interior to the edge. Using structural equation modelling, we
 showed that such intraspecific leaf trait response to habitat
 fragmentation had translated into significant plant afterlife effects on
 leaf decomposition, leading to decreased leaf decomposition rates from the
 forest interior to the edge. Importantly, the effects of intraspecific
 leaf trait variation were additive to and stronger than the effects from
 local environmental changes due to edge effects and habitat loss. Our
 experiment provides the first quantitative study showing that
 intraspecific leaf trait response to edge effects is an important driver
 of the decrease in leaf decomposition rate in fragmented forests. By
 extending the trait-based response-effect framework towards the individual
 level, intraspecific variation in leaf economics traits can provide the
 missing functional link between environmental change and ecological
 processes. These findings suggest an important area for future research on
 incorporating ITV to understand and predict changes in ecosystem
 functioning in the context of global change.
description: We conducted island-level reciprocal transplant decomposition
 experiments between forest edges and interiors on a locally abundant
 native understory species, <em>Vaccinium carlesii</em>
 (Ericaceae), to disentangle the relative effects of intraspecific leaf
 trait variation vs. altered environmental conditions on leaf decomposition
 rates in forest fragments.
description: # Intraspecific leaf trait variation mediates edge effects on litter
 decomposition rate in fragmented forests
 On 20 islands in the
 Thousand Island Lake, China, we quantified intraspecific leaf trait shifts
 of a widely distributed shrub species, *Vaccinium carlesii*, in response
 to habitat fragmentation. Using a reciprocal transplant decomposition
 experiment between forest edge and interior on 11 islands with varying
 areas, we disentangled the relative effects of intraspecific leaf trait
 variation vs. altered environmental conditions on leaf decomposition rates
 in forest fragments. ## Description of the data and file structure The
 datasets include two data files: donor.csv and recipient.csv The donor.csv
 data file includes leaf trait data for 535 plant individuals across 20
 islands in the Thousand Island Lake: tree_id: donor plant id. spad: leaf
 chlorophyll content (SPAD) of the donor plant. ldmc: leaf dry matter
 content (g/g) of the donor plant. sla: specific leaf area (cm2/g) of the
 donor plant. la: leaf area (mm2) of the donor plant. lt: leaf thickness
 (mm) of the donor plant. herbivory: herbivory degree of the donor plant.
 isl: island id. donor_dist: distance to forest edge (m). area: island area
 (ha). decomp: whether the individual was used in reciprocal decomposition
 experiment (recip) or not (no). loc: location of the individual on the
 island. donor_op: canopy openness at the donor site. misleaf.n: number of
 missing leaves (based on stem or petiole clues) on sampled branches.
 existleaf.n: number of persist leaves on sampled branches. totleaf.n:
 misleaf.n+existleaf.n The recipient.csv data file includes data for path
 analyses, including decomposition experiment data for 804 litter bags,
 corresponding leaf trait data of the donor plant, and environmental data
 for both recipient site and donor site: tree_id: donor plant id.
 decomp_site: decomposition experiment site id. decomp_op: canopy openness
 of decomposition site. decomp_prop: proportion decomposed of the litter
 bag. decomp_loc: location of the decomposition site (interior or edge).
 decomp_dist: distance of the decomposition site to the forest edge.
 decomp_day: number of days of the litter bag in the field. decomp_depth:
 litter depth near each leaf litter bag. leaftype: leaf type within each
 litter bag (D for damaged and I for intact). leaftype_n: leaf type
 (numeric) within each litter bag (1 for damaged and 2 for intact). isl:
 island id. spad: leaf chlorophyll content (SPAD) of the donor plant. ldmc:
 leaf dry matter content (g/g) of the donor plant. sla: specific leaf area
 (cm2/g) of the donor plant. la: leaf area (mm2) of the donor plant. lt:
 leaf thickness (mm) of the donor plant. donor_op: canopy openness at the
 donor site (same as donor_op in donor.csv). donor_dist: distance to forest
 edge (m) of the donor plant (same as donor_dist in donor.csv). area:
 island area (ha). herbivory: herbivory degree of the donor plant.