Allié Elodie, Pélissier Raphaël, Engel Julien, Petronelli Pascal, Freycon Vincent, Deblauwe Vincent, Soucémarianadin Laure, Weigel Jean, Baraloto Christopher
Université des Antilles et de la Guyane, UMR EcoFoG, Kourou, France.
IRD, UMR AMAP, Montpellier, France.
PLoS One. 2015 Nov 4;10(11):e0141488. doi: 10.1371/journal.pone.0141488. eCollection 2015.
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.
我们研究了法属圭亚那帕拉库低地森林群落中树木与土壤的栖息地关联。我们分析了一个大型数据集，该数据集整合了六个总面积为37.5公顷的永久样地，其中广泛的激光雷达衍生地形数据以及土壤化学和物理数据已与精确的植物学测定数据相结合。距最近溪流的相对海拔地图总结了土壤肥力和水文形态特征，季节性被淹没的低地土壤磷含量和碱基饱和度较高，而高原土壤碳、氮和铝含量较高。我们通过生成保留原始地图自相关性的随机光栅图像的蒙特卡罗模拟，对树种密度与环境地图之间的相关性进行了统计检验。在每公顷至少有一株茎干的94个分类单元中，近四分之三的分类单元显示树木密度与相对海拔之间存在显著相关性，揭示了在丰度方面不同的物种 - 栖息地关联，季节性被淹没的低地（占物种的24.5%）和排水良好的高原（占物种的48.9%）。我们还观察到物种对有或没有陡坡环境的偏好（分别为13.8%和10.6%）。我们观察到在该地区密切相关的物种经常与不同的土壤栖息地相关联（在具有显著关联检验的同属物种的14个属中，有70%），这表明物种 - 栖息地关联在这个树木群落中已经多次出现。我们还测试了具有相似栖息地偏好的物种是否共享功能策略。我们发现季节性被淹没森林的 specialist 往往比高原上的物种具有更小的树高（最大直径）。我们的结果强调了树木 - 土壤栖息地关联在精细空间尺度上构建多样群落的重要性，并表明需要进一步研究以区分与扩散限制、生物相互作用和环境过滤相关的群落组装机制与物种 - 栖息地关联。此外，它们提供了一个框架，可用于推广到热带森林地区。
