Effects of Rocky Desertification on Soil Bacterial Community in Alpine Grasslands of the Qinghai-Tibet Plateau

Abstract

The composition of soil microbial communities can be used as a crucial predictor of alpine grassland ecosystem. Climate change and human disturbance has resulted in intensified degradation of ecosystem , such as grassland rocky desertification, which may alter the structure and composition of the microorganisms of soil. However, little is known about the effects of rocky desertification on soil microbial communities. Here, we investigated five different levels of rocky desertification grassland in the Qinghai-Tibet Platea, including nil-rock desertification (NRD); potential rocky desertification (PRD); light-rocky desertification (LRD); moderate-rocky desertification (MRD); and severe-rocky desertification (SRD), we compared the soil bacterial community and soil physiochemical properties under different rocky desertification. The result showed that rocky desertification significantly changed the composition of soil bacterial communities, but had no significant effect on the diversity of bacterial communities. At the same time as rocky desertification increase, soil organic carbon (SOC), total nitrogen (TN), alkali hydrolysable nitrogen (AN), available phosphorus (AP) and available potassium (AK) decreased significantly, while soil pH, total phosphorus (TP); and total potassium (TK) increased. Redundancy analysis revealed that pH, AK, TP, and SOC are key factors influenced soil bacterial communities. Our finding provides basic information and scientific reference for the restoration of the rocky desertification of alpine grasslands.

Keywords: Qinghai-Tibet Plateau, alpine grassland, rocky desertification, soil properties, soil bacterial community.