Department of Biology and Environmental Sciences, Auburn University at Montgomery, 7061 Senator's Drive, Montgomery, Alabama, 36117, USA.
Tyson Research Center, Washington University in St. Louis, 6750 Tyson Valley Rd, Eureka, Missouri, 63025, USA.
Ecology. 2020 Nov;101(11):e03147. doi: 10.1002/ecy.3147. Epub 2020 Sep 28.
Theory predicts that stable species coexistence will occur when population growth rates of competitively dominant species are suppressed when at high conspecific density. Although there is now compelling evidence that plant communities exhibit negative density dependence, the relative importance of the underlying processes leading to these patterns is rarely tested. We coupled reciprocal greenhouse and field experiments with community dynamics modeling to untangle the relative importance of soil biota from competition as stabilizing forces to coexistence. We found that (1) plant-soil biotic interactions compared to competitive interactions were stronger stabilizing forces, (2) only the strength of plant-soil biotic interactions was dependent on plant evolutionary history, and (3) the variation in the strength of plant-soil biotic interactions was correlated with relative abundance patterns in an opposite way than was the variation in the strength of competitive interactions. Collectively, our results demonstrate the fundamental role soil biota have in maintaining plant community diversity.
理论预测，当竞争优势物种的种群增长率在同种密度高时受到抑制时，稳定的物种共存将发生。尽管现在有令人信服的证据表明植物群落表现出负密度依赖性，但导致这些模式的潜在过程的相对重要性很少得到检验。我们将互惠温室和田间实验与群落动态模型相结合，以理清导致共存的土壤生物区系和竞争作为稳定力量的相对重要性。我们发现：(1) 与竞争相互作用相比，植物-土壤生物相互作用是更强的稳定力量；(2) 只有植物-土壤生物相互作用的强度取决于植物的进化历史；(3) 植物-土壤生物相互作用强度的变化与相对丰度模式呈相反的相关性，而竞争相互作用强度的变化则不是。总的来说，我们的结果表明，土壤生物在维持植物群落多样性方面具有基础性作用。
