LAUSR

Abstract A large quantity of carbon (C) storage in peatland soils plays an important role in global C cycling. Microbial resource limitation and environmental factors can drive C cycling. However, the microbial resource limitation and regulator of C cycling in such an ecosystem are debated and still unclear. Therefore, this study chose Zoige, the largest peatland in the Qinghai-Tibet Plateau of China, to identify microbial resource limitation by analyzing ecoenzymatic stoichiometry and the regulation of soil organic C (SOC) through the interrelationships correlating SOC to abiotic (soil properties) and biotic factors (ecoenzyme activities, microbial communities, and abundance). The results demonstrated that soil microbial resource limitation varied in different seasons, across peatland types, and with depths; SOC content was more affected by abiotic factors (total nitrogen, total phosphorus, Olsen-phosphorus, moisture content) than biotic factors at the regional scale, and the factors driving C cycling differed among peatland types at the subregional scale. The path analysis further emphasized the importance of abiotic factors in C cycling, especially total nitrogen. This study provides important information for the understanding regulator of C cycling in peatland soils, which may help mitigate global climate change.