Using functional traits and phylogenetic trees to examine the assembly of tropical tree communities

Christopher Baraloto (1) , Olivier J. Hardy (2) , C. E. Timothy Paine (1, 3) , Kyle G. Dexter (4) , Corinne Cruaud (5) , Luke T. Dunning (6, 7) , Mailyn-Adriana Gonzalez (4, 8) , Jean-Francois Molino (9) , Daniel Sabatier (9) , Vincent Savolainen (6, 10) , Jerome Chave (4)

1 ECOFOG - Ecologie des forêts de Guyane
2 Fac Sci
3 Inst Evolutionary Biol & Environm Studies
4 EDB - Evolution et Diversité Biologique
5 Inst Genom
6 Ascot SL5 7PY
7 Auckland Mail Ctr
8 Dept Ciencias Biol
9 UMR AMAP - Botanique et Modélisation de l'Architecture des Plantes et des Végétations
10 Richmond TW9 3DS

1. Niche theory proposes that species differences underlie both coexistence within communities and the differentiation in species composition among communities via limiting similarity and environmental filtering. However, it has been difficult to extend niche theory to species-rich communities because of the empirical challenge of quantifying niches for many species. This has motivated the development of functional and phylogeny-based approaches in community ecology, which represent two different means of approximating niche attributes. 2. Here, we assess the utility of plant functional traits and phylogenetic relationships in predicting community assembly processes using the largest trait and phylogenetic data base to date for any set of species-rich communities. 3. We measured 17 functional traits for all 4672 individuals of 668 tree species co-occurring in nine tropical rain forest plots in French Guiana. Trait variation was summarized into two ordination axes that reflect species niche overlap. 4. We also generated a dated molecular phylogenetic tree based on DNA sequencing of two plastid loci (rbcL and matK) comprising 97% of the individuals and 91% of the species in the plots. 5. We found that, on average, co-occurring species had greater functional and, to a lesser extent, phylogenetic similarity than expected by chance. 6. We also found that functional traits and their ordination loadings showed significant, albeit weak, phylogenetic signal, suggesting that phylogenetic distance provides pertinent information on niche overlap in tropical tree communities. 7. Synthesis. We provide the most comprehensive examination to date of the relative importance of environmental filtering and limiting similarity in structuring tropical tree communities. Our results confirm that environmental filtering is the overriding influence on community assembly in these species-rich systems.

Mots clés: competition; determinants of plant community diversity and structure; environmental filtering; French Guiana; functional traits; limiting similarity; niche; phylogenetic signal; tropical forests; WITHIN-SPECIES VARIATION; RAIN-FOREST TREES; SPATIAL SCALES; ECOLOGICAL COMMUNITIES; EVOLUTIONARY PROCESSES; ENVIRONMENTAL FILTERS; PLANT-COMMUNITIES; AMAZONIAN FOREST; FISH COMMUNITIES; FLOWERING PLANTS

Domaines: Sciences agricoles

Christopher Baraloto, Olivier J. Hardy, C. E. Timothy Paine, Kyle G. Dexter, Corinne Cruaud, et al.. Using functional traits and phylogenetic trees to examine the assembly of tropical tree communities. African Journal of Ecology, 2012, 100 (3), pp.690 - 701. ⟨10.1111/j.1365-2745.2012.01966.x⟩. ⟨hal-01032423⟩