Contrasting tissue strategies explain functional beta diversity in Amazonian trees C. Fortunel, C.E.T. Paine, N. Kraft, P.V.A. Fine, C. Baraloto*

Global changes in the tropics Land use changes through logging, deforestation, fragmentation, and fire use Climate changes with increases in extreme climatic events (e.g. droughts) Lewis et al Science Asner et al Conserv Lett Introduction Material and methodsResultsConclusion and perspectives

Impact on functional diversity Reu et al Biogeosciences Fig. 2. Mean shifts in the geographic variation of functional richness (FR) between present-day (1960–1989) and future climate scenarios (2070–2099) B1 (a) and A2 (b). FR increase and decrease is calculated relative to FR of present-day climates. Loss of biodiversity, especially in the tropics, with consequences for ecosystem services Predictions of loss of functional diversity limited by poor description of spatial patterns Introduction Material and methodsResultsConclusion and perspectives

Community assembly Regional species pool Local community Stochastic processesNiche-based processes Dispersal limitation Speciation rate Demographic stochasticity Species functional strategies Niche differentiation (limiting similarity) Density-dependent mechanisms (e.g. Janzen-Connell) Environmental filtering Introduction Material and methodsResultsConclusion and perspectives

Fitness Community assembly and species traits Reproduction Growth Survival Introduction Material and methodsResultsConclusion and perspectives Trait = any morphological, physiological or phenological feature measurable at the individual level (Violle et al Oikos) Traits reflect tradeoffs that determine Species performance in a given environment Species abundances along environmental gradients Importance of environmental filtering Ex: environmental filtering on SLA Kraft et al Science To what extent environmental filtering has predictable consequences on the functional composition of communities across the landscape?

Functional strategies of tropical trees leaf – stem economics 668 species, French Guiana (project BRIDGE) Baraloto et al Ecology Letters Fortunel et al. submitted leaf – wood (stem/root) economics 800 species, French Guiana and Peru (project AmaLin) Introduction Material and methodsResultsConclusion and perspectives

Regional pool (trait distribution) Terra firme TF Seasonally flooded SF White sand WS wood economics (stem/root) leaf economics Wood densitySLA Prediction of direction of environmental filtering Introduction Material and methodsResultsConclusion and perspectives

Plot network of AmaLin project Introduction Material and methodsResultsConclusion and perspectives 74 plots Modified-Gentry French Guiana and Peru Baraloto et al Global Change Biology

Three contrasting habitats across a broad environmental gradient Terra firme (TF) Seasonnally flooded (SF) White sand (WS) Botanical records (species identification and abundance) Description of environmental factors (climate and soil) Environmental factorsPlots per habitats Introduction Material and methodsResultsConclusion and perspectives

Functional trait measurements For each species in each plot, traits were measured at the level of: Leaf SLA, LA, toughness, thickness, LTD, LChl, LCC, LNC, LC:N, LPC, LKC, L 13 C, L 15 N Stem wood density, humidity Trunk bark thickness Root wood density, humidity Introduction Material and methodsResultsConclusion and perspectives

Evaluation of environmental filtering Regional species pool (FG or Peru) 999 random communities (equal number of individuals x) Random assemblage function of species abundances irrespective of species traits Focal plot (number of individuals=x) Observed community functional composition Community-weighted mean Convex Hull volume Predicted distribution of community functional composition Community-weighted mean Convex Hull volume Introduction Material and methodsResultsConclusion and perspectives For each of 13 plots Species traits Species abundance

TF G4 SF G8 WS G2 wood economicsleaf economics Introduction Material and methodsResultsConclusion and perspectives Environmental filtering on community functional composition

Introduction Material and methodsResultsConclusion and perspectives CH overlap Density

Directional shifts in community functional composition across the Amazonian landscape Environmental filtering for denser leaf, stem and root tissues in dry and poor environments. Terra firme (TF) Seasonnally flooded (SF) White sand (WS) Wood density or 1/SLA Wood density or 1/SLA Introduction Material and methodsResultsConclusion and perspectives

Perspectives Implications for modeling community shifts across the landscape Implications for ecosystem services under global changes scenarios Introduction Material and methodsResultsConclusion and perspectives

Research was supported by a collaborative NSF DEB / to CB and PVAF and by an INRA Package grant to CB.