【摘要】 尽管微生物-气候的相互作用已得到越来越多的研究者和决策者的认可,但微生物的高多样性和对气候环境变化多变量的响应导致预测微生物在未来气候背景下的分布格局非常困难.本研究依托于中国土壤微生物组计划,基于采集自中国东部森林的1600多个样品的16S r RNA基因测序数据,首先证实了微生物群落组成和多样性的纬度分布规律且温度对微生物群落组成有显著的直接作用.其次,利用核心微生物代替整体群落来进行多样性的缩减,并将这些核心微生物根据其对环境的偏好性划分为不同的生态集群,这些生态集群在空间上的热点区域,即高丰度区域相互不重叠.此外,通过Cubist模型预测未来不同气候变化情景下(RCP2.6和RCP8.5)各生态集群的丰度变化并将其投影到中国森林生态系统分布区域,通过与现在的分布格局做对比得到增温驱动的生态集群空间分布格局的变化.这些变化一方面可以指示集群内微生物对未来气候变化的适应性,另一方面考虑到每一类生态集群所代表的环境偏好性,这些变化也可进一步用来指示未来气候变化背景下土壤属性的变化.更多还原

【Abstract】 Terrestrial species are predicted to migrate northward under global warming conditions, yet little is known about the direction and magnitude of change in microbial distribution patterns. In this continental-scale study with more than 1600 forest soil samples, we verify the existence of core microbiota and lump them into a manageable number of eco-clusters based on microbial habitat preferences.By projecting the abundance differences of eco-clusters between future and current climatic conditions,we observed the potential warming-driven migration of the core microbiota under warming, partially verified by a field warming experiment at Southwest China. Specifically, the species that favor low p H are potentially expanding and moving northward to medium-latitudes(25°–45°N), potentially implying that warm temperate forest would be under threat of soil acidification with warming. The eco-cluster of high-p H with high-annual mean temperature(AMT) experienced significant abundance increases at middle-(35°–45°N) to high-latitudes(> 45°N), especially under Representative Concentration Pathway(RCP) 8.5, likely resulting in northward expansion. Furthermore, the eco-cluster that favors low-soil organic carbon(SOC) was projected to increase under warming scenarios at low-latitudes(< 25°N),potentially an indicator of SOC storage accumulation in warmer areas. Meanwhile, at high-latitudes(> 45°N) the changes in relative abundance of this eco-cluster is inversely related with the temperature variation trends, suggesting microbes-mediated soil organic carbon changes are more responsive to temperature variation in colder areas. These results have vital implications for the migration direction of microbial communities and its potential ecological consequences in future warming scenarios.更多还原