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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. 2011. ScienceAsner et al. 2010. Conserv Lett
Introduction Material and methods ResultsConclusion and perspectives
Impact on functional diversity
Reu et al. 2011. 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 methods ResultsConclusion 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 methods ResultsConclusion and perspectives
Fitness
Community assembly and species traits
Reproduction
Growth
Survival
Introduction Material and methods ResultsConclusion and perspectives
•Trait = any morphological, physiological or phenological feature measurable at the individual level(Violle et al. 2007. Oikos)
•Traits reflect tradeoffs that determine • Species performance in a given environment• Species abundances along environmental gradients
•Importance of environmental filteringEx: environmental filtering on SLAKraft et al. 2008. 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. 2010. Ecology Letters
0.0 0.2 0.4 0.6 0.8 1.0
0.0
0.2
0.4
0.6
0.8
1.0
0.00.20.40.60.81.0
0.0
0.2
0.4
0.6
0.8
1.0
LChl
LthickLtough
L13C
LA
LC.N
LCC
LKC
LNC
LPC
LTD
R wood H
R wood D
S wood H
S wood D
SLA
Bark thick
Dim 1: 23.02 %
Dim
2: 1
5.45
%
Fortunel et al. submitted
leaf – wood (stem/root) economics
800 species, French Guiana and Peru
(project AmaLin)
Introduction Material and methods ResultsConclusion and perspectives
Regional pool (trait distribution)
Terra firme TF
Seasonally floodedSF
White sandWS
wood economics(stem/root)
leaf economics
Wood density SLA
Prediction of direction of environmental filtering
Introduction Material and methods ResultsConclusion and perspectives
Plot network of AmaLin project
Introduction Material and methods ResultsConclusion and perspectives
74 plotsModified-GentryFrench Guiana and Peru
Baraloto et al. 2011. Global Change Biology
Three contrasting habitatsacross 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 factors Plots per habitats
Introduction Material and methods ResultsConclusion and perspectives
Functional trait measurements
For each species in each plot, traits were measured at the level of:
• LeafSLA, LA, toughness, thickness, LTD, LChl, LCC, LNC, LC:N, LPC, LKC, L 13C, L 15N
• Stemwood density, humidity
• Trunkbark thickness
• Rootwood density, humidity
Introduction Material and methods ResultsConclusion 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 methods ResultsConclusion and perspectives
For each of 13 plots• Species traits• Species abundance
TFG4
SFG8
WSG2
wood economics leaf economics
Introduction Material and methods ResultsConclusion and perspectives
Environmental filtering on community functional composition
Environmental filtering on community functional composition
Introduction Material and methods ResultsConclusion and perspectives
CH overlap CH overlap
Den
sity
Den
sity
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 densityor 1/SLA
Wood densityor 1/SLA
Introduction Material and methods ResultsConclusion and perspectives
Perspectives
• Implications for modeling community shifts across the landscape
• Implications for ecosystem services under global changes scenarios
Introduction Material and methods ResultsConclusion and perspectives
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