title: Functional traits help predict post-disturbance demography of tropical trees.
abstract: How tropical tree species respond to disturbance is a central issue of forest ecology, conservation and resource management. We define a hierarchical model to investigate how functional traits measured in control plots relate to the population change rate and to demographic rates for recruitment and mortality after disturbance by logging operations. Population change and demographic rates were quantified on a 12-year period after disturbance and related to seven functional traits measured in control plots. The model was calibrated using a Bayesian Network approach on 53 species surveyed in permanent forest plots (37.5 ha) at Paracou in French Guiana. The network analysis allowed us to highlight both direct and indirect relationships among predictive variables. Overall, 89% of interspecific variability in the population change rate after disturbance were explained by the two demographic rates, the recruitment rate being the most explicative variable. Three direct drivers explained 45% of the variability in recruitment rates, including leaf phosphorus concentration, with a positive effect, and seed size and wood density with negative effects. Mortality rates were explained by interspecific variability in maximum diameter only (25%). Wood density, leaf nitrogen concentration, maximum diameter and seed size were not explained by variables in the analysis and thus appear as independent drivers of post-disturbance demography. Relationships between functional traits and demographic parameters were consistent with results found in undisturbed forests. Functional traits measured in control conditions can thus help predict the fate of tropical tree species after disturbance. Indirect relationships also suggest how different processes interact to mediate species demographic response.
authors.affiliation: Cirad - Université de La Réunion, UMR PVBMT, 7 chemin de l'IRAT, Saint Pierre, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Flores
authors.affiliation: Cirad, UMR Ecologie des Forêts de Guyane, Kourou, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Hérault
authors.affiliation: Cirad, UR B&SEF, Biens et Services des Ecosystèmes Forestiers tropicaux, Campus International de Baillarguet, TA C-105/D, Montpellier, France.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Delcamp
authors.affiliation: Centre d'Écologie Fonctionnelle et Évolutive, CNRS - UMR 5175, Montpellier, France.
authors.forename: Éric
authors.initials: É
authors.lastname: Garnier
authors.affiliation: Cirad, UR B&SEF, Biens et Services des Ecosystèmes Forestiers tropicaux, Campus International de Baillarguet, TA C-105/D, Montpellier, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Gourlet-Fleury
mesh_terms: D001499:Bayes Theorem; D004463:Ecology; D017753:Ecosystem; D005616:French Guiana; D011157:Population Dynamics; D019655:Quantitative Trait, Heritable; D014197:Trees; D014329:Tropical Climate