山地土壤微生物地理分布格局及其驱动机制

土壤微生物不仅是陆地生态系统的重要组成部分，也是地上、地下过程与功能有机结合的重要纽带。分子生物技术的发展以及土壤微生物分离和鉴定准确性的提高，推动了土壤微生物生物地理学的不断发展，但宏观尺度上的格局特征与区域规律尚未揭示。本文集成分析了全球不同气候带、不同植被类型的土壤微生物群落组成（生物多样性）沿海拔梯度的地理分布格局，发现在全球尺度上并无一致规律，线性（递增或递减）、非线性（单峰或双峰）、无固定趋势3种地理格局并存。植被类型、植物多样性、土壤pH及其它物理化学性质、气候等各种因素，都有可能决定某一地区的土壤微生物多样性的海拔梯度分布格局。全球尺度上的现有数据分析发现，海拔跨度和气候的影响较为明显，二者实际上综合反映了大尺度上气候决定着山地土壤微生物的地理分布格局，这与传统的生物地理学观点是一致的，其它生态环境因子如地理坐标、植被类型、土壤微生物类型、土壤pH等的影响处于从属地位。然而，当前山地土壤微生物生物地理学的研究仍有较多局限性，全球更多山地、更大海拔跨度的土壤微生物研究、更精确的微生物分离鉴定技术、更多样的环境与生物驱动因素分析，以及更多现代生物地理学研究方法的使用，将有助于土壤微生物地理分布格局的深入研究，及其与气候、土壤和生态系统关系的深入挖掘，这对深刻认识土壤微生物的空间分布规律，从而更好地开发和利用土壤微生物资源，具有重要的理论与实践意义。

Geographical Distribution Pattern of Soil Microorganisms in Mountains and Its Driving Mechanism

Soil microorganisms are not only an important component of terrestrial ecosystem, but also a vital bond between processes and functions in aboveground and underground ecosystems. The development of molecular biotechnology and the precise separation and identification of soil microorganisms have promoted the research advances of soil microbial biogeography, but regional patterns and regularities have not been investigated in the macro-scale so far. This paper synthesized and analyzed the geographical distribution patterns of soil microbial communities (biodiversity) along altitudinal gradients in different climatic zones and in various vegetation types all over the world. We found that, at the global scale, there is no coincident regularity but coexists three patterns, i.e. linear trend (increasing or decreasing), non-linear trend (one peak or two peaks) and no trend. Multiple biological and non-biological factors, such as vegetation type, plant diversities, soil pH and climate, may determine the altitudinal geographical pattern of soil microorganism diversity in a site. The comprehensive analysis of the available data showed that the elevation range and climate have the most significant influences on the global patterns of soil microorganism in mountain soils, implying that the climate of large-scale determine the geographical distribution pattern of soil microorganism along the mountainous gradient. This is in agreement with the traditional view of biogeography. Other environmental factors, such as geographic coordinates, vegetation types, soil microorganism types and soil pH, are less important. However, current soil microorganism biogeography studies are yet very limited, investigations on more mountains with larger elevation ranges, more precise identification of microorganisms, more environmental driving factors, and more utilizations of modern biogeographical methodology should be involved in future researches of soil microorganisms to help deepening the exploration of geographical patterns of soil microorganisms and their relationships with climates, soils and ecosystems. A better understanding of the spatial distribution regularity of soil microorganisms is of importance in better utilizing and developing soil microbial resources.