Legumes provide an essential service to ecosystems by capturing nitrogen from the atmosphere and delivering it to the soil, where it may then be available to other plants. However, this facilitation by legumes has not been widely studied in global tropical forests. Demographic data from 11 large forest plots (16–60 ha) ranging from 5.25° S to 29.25° N latitude show that within forests, leguminous trees have a larger effect on neighbor diversity than non-legumes. Where soil nitrogen is high, most legume species have higher neighbor diversity than non-legumes. Where soil nitrogen is low, most legumes have lower neighbor diversity than non-legumes. No facilitation effect on neighbor basal area was observed in either high or low soil N conditions. The legume–soil nitrogen positive feedback that promotes tree diversity has both theoretical implications for understanding species coexistence in diverse forests, and practical implications for the utilization of legumes in forest restoration.

豆科植物通过从大气中捕获氮并将其输送到土壤中，然后再供其他植物使用，从而为生态系统提供必要的服务。然而，在全球热带森林中尚未广泛研究豆科植物的促成作用。来自北纬5.25°至北纬29.25°的11个大型林区（16-60公顷）的人口统计数据表明，在森林中，豆科树木对邻域多样性的影响要大于非豆科植物。在土壤氮含量高的地区，大多数豆类物种比非豆类具有更高的邻居多样性。在土壤氮含量低的地方，大多数豆类的邻居多样性要比非豆类低。在高氮或低氮条件下均未观察到对邻近基底面积的促进作用。