Abstract: Soil microbes are the essential participants in ecosystem processes, controlling the turnover of the largest organic matter pool in the terrestrial biosphere. In recent years, the variations of soil microbial diversity patterns and community structures have been extensively studied with the elevation. Here, "Elevation gradient" and "Soil fertilization" were selected as the keywords. A total of 717 papers were collected from the “Web of Science” core collection database and CNKI and was used to perform the number of posts, keyword co-occurrence analysis and literature co-citation cluster analysis using Citespace visual literature. The results showed that the response of soil microorganisms  to elevation gradients had been growing rapidly since 2000 and there was consistency in the domestic and international research trends. It was found that “forest”, “elevation”, “soil fungi”and “plant” were the frequency characteristics of keywords, which further indicated that the spatial variation of soil microorganisms was one of the important research directions in the forest ecosystem. In addition, soil microbial diversity and community structures showed a clear altitudinal distribution pattern at the regional spatial scale, whereas there were five patterns of increasing, decreasing, “peak”, “U” pattern and no significant changes and mainly decreased with the elevation. Moreover, the environmental driving factors of soil microbial communities were also controversial, including soil nutrients, vegetation specificity and climatic factors. Therefore, it is necessary to explore the distribution change mechanism of soil microbial community and diversity in the future according to the characteristics of the study region, revealing the variation degree of soil characteristics and microbial community at different scales, and further quantify the relationship between soil microbial community and related environmental factors. It provides novel insights for the study of the basic distribution and dynamics of microorganisms in terrestrial ecosystems.

Key words: CiteSpace, Elevation gradient, Soil microorganisms, Driving factors