School of Life Sciences, South China Normal University, Guangzhou, 510631, Guangdong, China.
State Key Laboratory of Earth Surface Processes and Resource Ecology and MOE Key Laboratory for Biodiversity Science and Ecological Engineering, Beijing Normal University, Beijing, 100875, China.
ISME J. 2019 Nov;13(11):2846-2855. doi: 10.1038/s41396-019-0477-x. Epub 2019 Jul 29.
It is well accepted that environmental heterogeneity and dispersal are key factors determining soil bacterial community composition, yet little is known about the role of local biotic interactions. Here we address this issue with an abundance-manipulation experiment that was conducted in a semiarid grassland. We manually increased the abundance of six randomly chosen resident bacterial species in separate, closed, communities and allowed the communities to recover in situ for 1 year. The single episode of increase in the abundance of different species drove species-specific community divergence accompanied by a decline in local diversity. Four of the six added species caused a decrease in the abundance of their closely related species, suggesting an important role of interspecific competition in driving the observed community divergence. Our results also suggested a lack of effective population regulations to force the relative abundance of manipulated species to revert to original level, which would allow persistence of the divergence among soil bacterial communities. We concluded that biotic interactions were important in determining soil bacterial community composition, which could result in substantial variation in soil bacterial community composition in abiotically homogenous environment.
人们普遍认为，环境异质性和扩散是决定土壤细菌群落组成的关键因素，但人们对本地生物相互作用的作用知之甚少。在这里，我们通过在半干旱草原上进行的丰度操纵实验来解决这个问题。我们在单独的封闭群落中手动增加了六个随机选择的常驻细菌物种的丰度，并允许群落原地恢复 1 年。不同物种丰度的单次增加导致了特定物种的群落分歧，同时降低了局部多样性。六种添加物种中的四种导致其密切相关物种的丰度下降，表明种间竞争在驱动观察到的群落分歧中起着重要作用。我们的结果还表明，缺乏有效的种群调节来迫使受操纵物种的相对丰度恢复到原始水平，这将允许土壤细菌群落之间的分歧持续存在。我们得出结论，生物相互作用是决定土壤细菌群落组成的重要因素，这可能导致在非生物同质环境中土壤细菌群落组成发生实质性变化。
