Data from: Potential trajectories of old-growth Neotropical forest functional composition under climate change

Quantifying relationships between plant functional traits and abiotic
gradients is valuable for evaluating potential responses of forest
communities to climate change. However, the trajectories of change
expected to occur in tropical forest functional characteristics as a
function of future climate variation are largely unknown. We modeled
community level trait values of Costa Rican rain forests as a function of
current and future climate, and quantified potential changes in functional
composition. We calculated per-plot community weighted mean (CWM) trait
values for leaf area (LA), specific leaf area (SLA), leaf dry matter
content (LDMC), leaf nitrogen (N) and phosphorus (P) content, and wood
basic specific gravity (WSG), for tree and palm species in 127 0.25 ha
plots. We modeled the response of CWM traits to current temperature and
precipitation gradients using generalized additive modeling. We then
predicted and mapped CWM traits values under current and future climate,
and quantified potential changes under a global warming scenario (RCP8.5,
year 2050). We calculated the area within the multi trait functional space
occupied by forest plots under both current and future climate, and
determined potential changes in functional space occupied by forest plots.
Overall, precipitation predicted CWM traits better than temperature.
Models indicated increases in CWM SLA, N and P, and a decrease in CWM LDMC
under climate change. Lowland forest communities converged on a single
direction of change towards more acquisitive CWM trait values, indicating
a change in forest functional composition resulting from a changed
climate. Functional space occupied by forest plots was reduced by 50%
under the future climate. Functional composition changes may have further
effects on forests ecosystem services. Assessing functional trait
spatial-gradients can help bridge the gap between species-based
biogeography and biogeochemical approaches to strengthen biodiversity and
ecosystem services conservation efforts.