Department of Biology, Stanford University, 371 Jane Stanford Way, Stanford, CA, 94305, USA.
Department of Botany and Plant Pathology, Oregon State University, 2082 Cordley Hall, Corvallis, OR, 97331, USA.
Ecol Lett. 2021 Feb;24(2):310-318. doi: 10.1111/ele.13647. Epub 2020 Nov 20.
Ecological communities typically contain more species when located within geologically older regions. This pattern is traditionally attributed to the long-term accumulation of species in the regional species pool, with local species interactions playing a minor role. We provide evidence suggesting a more important role of local species interactions than generally assumed. We assembled 320 communities of root-associated fungi under 80 species pools, varying species pool richness and the mean age of the sites from which the fungi were collected across a 4-myr soil chronosequence. We found that local diversity increased more with increasing species pool richness when species were from older sites. We also found that older species pools had lower functional and phylogenetic diversity, indicating greater competitive equivalence among species. Our results suggest that older regions have higher local richness not simply because older pools are more speciose but also because species have evolved traits that allow them to locally co-occur.
生态群落通常在地质年代较久远的地区包含更多的物种。这种模式传统上归因于物种在区域物种库中的长期积累，而本地物种相互作用的作用较小。我们提供的证据表明，本地物种相互作用的作用比普遍认为的更为重要。我们在一个 4 百万年的土壤时间序列中，从 80 个物种库中收集了 320 个根相关真菌群落，这些物种库的物种丰富度和采集真菌的地点的平均年龄各不相同。我们发现，当物种来自较老的地点时，本地多样性随物种库丰富度的增加而增加。我们还发现，较老的物种库具有较低的功能和系统发育多样性，这表明物种之间的竞争等价性更高。我们的结果表明，较老的地区具有更高的本地丰富度，不仅是因为较老的物种库更具物种多样性，还因为物种已经进化出了允许它们在本地共存的特征。
