Effect of snowpack on the soil bacteria of alpine meadows in the Qinghai-Tibetan Plateau of China

Abstract

Global climate change is accompanied by changes in the amounts of ice and snow. These changes have both a direct effect on the plant community structure, primary productivity and carbon cycle and an indirect influence on the belowground ecosystem. However, the effects of changes in snowpack on the soil environment and belowground ecological processes, particularly in soil microbial communities are still poorly understood in alpine meadows. We conducted a field study of controlled snowpack in the eastern margin of the Tibetan Plateau, where five treatments were set up, named as S0, S1, S2, S3, and S4 (S1: the amount of a natural snowpack; S2, S3, and S4 were twofold, threefold, and fourfold of S1, respectively; and S0: completely removed snow). Soil physicochemical properties, soil community structure and diversity measured by 16S rRNA gene amplicons were studied. The results indicated that 1) as snowpack increased, the average soil temperature decreased, but soil moisture and soil compaction increased; 2) soil chemical properties (pH, available nitrogen, available potassium, available phosphorus, total nitrogen, total potassium, total phosphorus and total soil organic carbon) all changed as snowpack changed; and 3) increasing snowpack led to a decrease in the relative abundance of Acidobacteria, but Bacteroidetes and Actinobacteria did not decline in response to increasing snowpack. In summary, these results showed that soil bacterial communities are sensitive to changes in snowpack in alpine meadows.