Data from: Intraspecific leaf trait variation mediates edge effects on litter decomposition rate in fragmented forests
Data files
Jan 10, 2024 version files 203.97 KB
Abstract
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.
README: Intraspecific leaf trait variation mediates edge effects on litter decomposition rate in fragmented forests
https://doi.org/10.5061/dryad.h44j0zpsv
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.
Methods
We conducted island-level reciprocal transplant decomposition experiments between forest edges and interiors on a locally abundant native understory species, Vaccinium carlesii (Ericaceae), to disentangle the relative effects of intraspecific leaf trait variation vs. altered environmental conditions on leaf decomposition rates in forest fragments.