Temporal 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.

中文翻译：

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青藏高原高寒草甸地土壤CO2排放的时间变化

人们对高海拔地区土壤CO ₂流出的时间变化及其与土壤微生物生物量和环境因素的直接联系了解甚少。在这项研究中，我调查了青藏高原高寒草甸地区土壤CO ₂流出量随时间的变化及其与土壤有机质，土壤微生物生物量和环境因子的关系。结果表明，高寒草甸土壤CO ₂外排量逐月显着变化。1月至5月以及10月至12月的土壤CO ₂外排总体低于6月至9月（p  <0.05）。在季节性基础上，土壤CO ₂在春季，秋季和冬季，外排比夏季低（p  <0.05）。此外，线性回归分析表明，土壤中CO ₂流出量的全年变化随土壤微生物量碳含量的增加而降低（p  <0.05）。土壤CO _2的流出与气温和积雪深度也呈正相关（p  <0.05）。多元回归和主成分回归分析表明，土壤CO ₂流出量的时间变化主要是由气温和土壤微生物量的每月和季节性变化引起的。