title: Pervasive Local-Scale Tree-Soil Habitat Association in a Tropical Forest Community.
abstract: We examined tree-soil habitat associations in lowland forest communities at Paracou, French Guiana. We analyzed a large dataset assembling six permanent plots totaling 37.5 ha, in which extensive LIDAR-derived topographical data and soil chemical and physical data have been integrated with precise botanical determinations. Map of relative elevation from the nearest stream summarized both soil fertility and hydromorphic characteristics, with seasonally inundated bottomlands having higher soil phosphate content and base saturation, and plateaus having higher soil carbon, nitrogen and aluminum contents. We employed a statistical test of correlations between tree species density and environmental maps, by generating Monte Carlo simulations of random raster images that preserve autocorrelation of the original maps. Nearly three fourths of the 94 taxa with at least one stem per ha showed a significant correlation between tree density and relative elevation, revealing contrasted species-habitat associations in term of abundance, with seasonally inundated bottomlands (24.5% of species) and well-drained plateaus (48.9% of species). We also observed species preferences for environments with or without steep slopes (13.8% and 10.6%, respectively). We observed that closely-related species were frequently associated with different soil habitats in this region (70% of the 14 genera with congeneric species that have a significant association test) suggesting species-habitat associations have arisen multiple times in this tree community. We also tested if species with similar habitat preferences shared functional strategies. We found that seasonally inundated forest specialists tended to have smaller stature (maximum diameter) than species found on plateaus. Our results underline the importance of tree-soil habitat associations in structuring diverse communities at fine spatial scales and suggest that additional studies are needed to disentangle community assembly mechanisms related to dispersal limitation, biotic interactions and environmental filtering from species-habitat associations. Moreover, they provide a framework to generalize across tropical forest sites.
authors.affiliation: Université des Antilles et de la Guyane, UMR EcoFoG, Kourou, France.
authors.forename: Elodie
authors.initials: E
authors.lastname: Allié
authors.affiliation: IRD, UMR AMAP, Montpellier, France.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Pélissier
authors.affiliation: CNRS, UMR EcoFoG, Kourou, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Engel
authors.affiliation: Cirad, UMR EcoFoG, Kourou, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Petronelli
authors.affiliation: Cirad, UPR BSEF, Montpellier, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Freycon
authors.affiliation: UMR Diade, Montpellier, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Deblauwe
authors.affiliation: Cirad, UMR EcoFoG, Kourou, France.
authors.forename: Laure
authors.initials: L
authors.lastname: Soucémarianadin
authors.affiliation: AgroParisTech, UMR EcoFoG, Kourou, France.
authors.forename: Jean
authors.initials: J
authors.lastname: Weigel
authors.affiliation: INRA, UMR EcoFoG, Kourou, France.|International Center for Tropical Botany, Department of Biological Sciences, Florida International University, Miami, FL, United States of America.
authors.forename: Christopher
authors.initials: C
authors.lastname: Baraloto
mesh_terms: D065928:Forests; D008954:Models, Biological; D012987:Soil; D014329:Tropical Climate
chemical_list: D012987:Soil