Abstract: Exploring the relationship between soil carbon sequestration and global warming is a critical issue. To clarify the characteristics of soil organic carbon (SOC) mineralization within aggregates in alpine wetlands in source region of the Yellow River,We conducted experiments to determine the SOC mineralization characteristics within aggregates across different particle sizes (>2 mm,2~0.25 mm,and <0.25 mm) in alpine wetland at 5℃,15℃ and 25℃ by alkali absorption method. The aim was to clarify the carbon sequestration features of soil aggregates in alpine wetlands under the context of global warming. The results showed that temperature wariation significantly affects the SOC mineralization within aggregates in alpine wetlands,and with mineralization amount of SOC in aggregates increasing at higher temperatures. The macro-aggregates (>2 mm and 2~0.25 mm) of alpine wetlands exhibited significantly higher SOC mineralization rates compared to micro-aggregates (<0.25 mm,P＜0.05). The temperature sensitivity coefficient (Q₁₀) of SOC mineralization within soil aggregates in alpine wetlands gradually increased with increasing temperature,and varied with particle size predominantly as (2~0.25 mm) > (>2 mm) > (<0.25 mm). These results suggest that rising temperature may diminish the carbon sequestration capacity of soil aggregates in alpine wetlands in source region of the Yellow River.

Key words: Source region of the Yellow River, Temperature, Aggregate, Organic carbon mineralization, Q₁₀, Alpine wetland

摘要： 探索土壤碳固存与全球气候变暖的关系是当前环境科学的研究热点。为厘清黄河源区高寒湿地土壤团聚体有机碳矿化特征，本研究利用碱液吸收法测定不同温度(5℃,15℃,25℃)条件下湿地土壤各粒径(>2 mm,2~0.25 mm和<0.25 mm)团聚体有机碳矿化特征，以期明晰全球变暖背景下高寒湿地土壤团聚体固碳特征。结果显示：温度变化对高寒湿地的土壤团聚体有机碳矿化具有显著影响，温度越高，团聚体有机碳矿化量越大；高寒湿地土壤大团聚体(>0.25 mm)有机碳矿化速率显著高于微团聚体(<0.25 mm，P＜0.05)；高寒湿地土壤团聚体有机碳矿化的温度敏感性系数(Q₁₀)随温度升高逐渐增加，随粒径变化由大到小依次为2~0.25 mm，>2 mm，<0.25 mm。综上所述，温度升高降低了黄河源区高寒湿地土壤团聚体的固碳能力。

关键词: 黄河源区, 温度, 团聚体, 有机碳矿化, Q₁₀, 高寒湿地