Temporal variations in soil CO2 efflux in an alpine meadow site on the Qinghai–Tibetan Plateau

Abstract

AbstractTemporal variations in soil CO2 efflux and its direct links to soil microbial biomass and environmental factors in high‐elevation regions are poorly understood. In this study, I investigated the variations in soil CO2 efflux over time and their relationships to soil organic matter, soil microbial biomass and environmental factors in an alpine meadow site on the Qinghai–Tibetan Plateau. The results showed notable monthly to seasonal changes in soil CO2 efflux in alpine meadows. The soil CO2 efflux was lower overall from January to May and from October to December than from June to September (p < 0.05); on a seasonal basis, the soil CO2 efflux was lower during the spring, autumn and winter than during the summer (p < 0.05). In addition, linear regression analysis showed that the temporal variations in soil CO2 efflux over the whole year decreased with soil microbial biomass carbon content (p < 0.05). Soil CO2 efflux was also positively related to air temperature and snow cover depth (p < 0.05). Multiregression and principal component regression analyses indicated that temporal variations in soil CO2 efflux were mainly caused by monthly and seasonal changes in air temperature and soil microbial biomass.