土壤微生物多样性海拔格局研究进展

生物多样性的海拔分布格局与维持机制是生物多样性与生态系统功能研究的热点领域。相比动植物多样性海拔分布格局,土壤微生物多样性海拔分布格局的研究还处在起步阶段。近年来,随着以罗氏454、Illumina Mi Seq等为代表的高通量测序平台的发展,土壤微生物海拔梯度分布格局的研究进展较快。对土壤微生物多样性海拔分布格局最新研究综述发现,土壤微生物海拔分布模式并不明确,表现为无趋势、下降、单峰或者下凹型等多种海拔分布模式。这与大型动植物并不相同,暗示其驱动机制可能存在一定的差异。微生物由于其个体微小、扩散能力强以及较高的多样性和个体丰度而在局域尺度上可能更易受到气候环境因素的影响。土壤pH、碳、氮等因子是影响微生物多样性和群落组成在海拔梯度上变异的重要因素。此外,温度和降水也具有重要作用。另外,除微生物自身属性以及取样限制外,测序深度可能是影响土壤微生物物种丰富度海拔分布格局的重要因素。目前,对土壤微生物群落的研究在功能基因、群落构建机制以及生态学理论的验证方面还存在着不足。未来的研究应进一步加大测序深度,增加取样密度,着重关注全球气候变化及生物多样性丧失背景下土壤微生物群落的构建和维持机制及其生态系统功能等方面。

Progress in the study of elevational patterns of soil microbial diversity

Elevational distribution pattern and maintenance of biodiversity are critical issues for a comprehensive study of biodiversity and ecosystem functioning. Compared to the well-known elevational diversity patterns of plants and animals, the study of elevational diversity patterns of soil microorganisms is still at the initial stage. The development of high-throughput sequencing platforms such as Roche 454 and Illumina MiSeq in recent years has led to rapid advancements in the study of the elevational distribution patterns of soil microbial diversity. This article describes an analysis of recent studies, which showed that the elevational distribution patterns of soil microbes were still obscure including no apparent patterns, decline patterns, hump-backed patterns and hollow patterns. However, it is certain that soil microbes do not follow the elevational diversity patterns of plants and animals, suggesting that the underlying mechanisms are different. Microorganisms may be more susceptible to changes in climate and environmental factors at the local elevational scale owing to their small size, strong dispersal ability, and high diversity and abundance. Soil pH, carbon, and nitrogen are important elements that affect the variation of microbial diversity and community composition at elevational gradients. Moreover, temperature and precipitation also play an important role. In addition to the properties of microorganisms and sampling limitation, the elevational patterns of soil microbial species richness may be affected by sequencing depth. At present, the study of soil microbial community in functional gene, community assembly mechanisms, and ecological theory verification still need further investigation. These findings suggest that the sequencing depth and sampling density should, therefore, be further increased in future related studies, and more studies should focus on the mechanisms of soil microbial community assembly and ecosystem functioning under the background of global climate change and biodiversity loss.