Altitudinal gradient drives significant changes in soil physico-chemical properties and microbial community after ecological restoration on Qinghai-Tibetan plateau

The construction of artificial ecological slopes is a favorable methods to restore the land degradation caused by human engineering activities. Soil microorganisms and nutrients are changed during ecological restoration, but their response to restoration efforts remains unclear at different spatial distances. This study investigated soil characteristics, soil microbial composition, soil metagenomics, and environmental factors across high-altitude gradients. The results showed that altitude, soil depth and pH were the main factors affecting the structure of soil microbial community. Among them, there were significant differences in spatial distance between Acidobacteria , Myxomycetes , Actinomycetes , Bacteroidetes, Blastomonas and Cyanobacteria . At the same time, microbial diversity was positively correlated with altitude, soil depth and pH. Soil pH, organic carbon, NH ₄ ⁺ -N, and water content were identified as the main environmental drivers of microbial community differences. Additionally, metagenomic analysis revealed that key genes involved in signaling( prkC / stkP ), biofilm formation༈ emaA , bapA ༉, and organic matter decomposition༈ TC.FEV.OM ༉ showed abundance variations along spatial gradients. Overall, the results highlight that spatial distance and soil nutrients are the key factors determining the differences in soil microbial community structure.