Tyson Research Center, Washington University in St. Louis, St. Louis, MO, USA.
Department of Biology, Washington University in St. Louis, St. Louis, MO, USA.
Science. 2017 Jun 30;356(6345):1389-1392. doi: 10.1126/science.aam5678.
Theory predicts that higher biodiversity in the tropics is maintained by specialized interactions among plants and their natural enemies that result in conspecific negative density dependence (CNDD). By using more than 3000 species and nearly 2.4 million trees across 24 forest plots worldwide, we show that global patterns in tree species diversity reflect not only stronger CNDD at tropical versus temperate latitudes but also a latitudinal shift in the relationship between CNDD and species abundance. CNDD was stronger for rare species at tropical versus temperate latitudes, potentially causing the persistence of greater numbers of rare species in the tropics. Our study reveals fundamental differences in the nature of local-scale biotic interactions that contribute to the maintenance of species diversity across temperate and tropical communities.
理论预测，热带地区更高的生物多样性是由植物与其天敌之间的专门相互作用维持的，这些相互作用导致同物种的负密度依赖性（CNDD）。通过使用全球 24 个森林样地的 3000 多种物种和近 240 万棵树，我们表明，树种多样性的全球模式不仅反映了热带与温带地区的 CNDD 更强，而且还反映了 CNDD 与物种丰度之间的关系的纬度转移。与温带地区相比，热带地区的稀有物种的 CNDD 更强，这可能导致热带地区更多稀有物种的持续存在。我们的研究揭示了在维持温带和热带群落物种多样性方面，本地尺度生物相互作用的本质差异。
