ter Steege Hans, Pitman Nigel C A, Phillips Oliver L, Chave Jerome, Sabatier Daniel, Duque Alvaro, Molino Jean-François, Prévost Marie-Françoise, Spichiger Rodolphe, Castellanos Hernán, von Hildebrand Patricio, Vásquez Rodolfo
Institute of Environmental Biology, Section Plant Ecology and Biodiversity, and the National Herbarium of the Netherlands NHN, Utrecht University branch, Sorbonnelaan 14-16, 3584 CA Utrecht, The Netherlands.
Nature. 2006 Sep 28;443(7110):444-7. doi: 10.1038/nature05134.
The world's greatest terrestrial stores of biodiversity and carbon are found in the forests of northern South America, where large-scale biogeographic patterns and processes have recently begun to be described. Seven of the nine countries with territory in the Amazon basin and the Guiana shield have carried out large-scale forest inventories, but such massive data sets have been little exploited by tropical plant ecologists. Although forest inventories often lack the species-level identifications favoured by tropical plant ecologists, their consistency of measurement and vast spatial coverage make them ideally suited for numerical analyses at large scales, and a valuable resource to describe the still poorly understood spatial variation of biomass, diversity, community composition and forest functioning across the South American tropics. Here we show, by using the seven forest inventories complemented with trait and inventory data collected elsewhere, two dominant gradients in tree composition and function across the Amazon, one paralleling a major gradient in soil fertility and the other paralleling a gradient in dry season length. The data set also indicates that the dominance of Fabaceae in the Guiana shield is not necessarily the result of root adaptations to poor soils (nodulation or ectomycorrhizal associations) but perhaps also the result of their remarkably high seed mass there as a potential adaptation to low rates of disturbance.
世界上最大的陆地生物多样性和碳储存库位于南美洲北部的森林中，近期人们才开始描述该地区大规模的生物地理格局和过程。在亚马逊盆地和圭亚那地盾拥有领土的九个国家中有七个已经开展了大规模森林清查，但热带植物生态学家对这些海量数据集的利用却很少。尽管森林清查通常缺乏热带植物生态学家所青睐的物种水平鉴定，但它们测量的一致性和广阔的空间覆盖范围使其非常适合进行大规模的数值分析，并且是描述南美洲热带地区生物量、多样性、群落组成和森林功能仍知之甚少的空间变化的宝贵资源。在这里，我们通过使用七个森林清查数据，并辅以在其他地方收集的性状和清查数据，展示了亚马逊地区树木组成和功能的两个主要梯度，一个与土壤肥力的主要梯度平行，另一个与旱季长度的梯度平行。该数据集还表明，豆科植物在圭亚那地盾的优势地位不一定是根系适应贫瘠土壤（结瘤或外生菌根关联）的结果，也可能是由于它们在那里具有极高的种子质量，这是对低干扰率的一种潜在适应。
