培养温度对不同类型茶园土壤有机碳矿化的影响

Effect of Temperature on Organic Carbon Mineralization in Two Types of Soil at Tea Plantations

室内模拟亚热带地区2种不同类型茶园土壤（黄壤和高山草甸土）在3种温度（10、20和30℃）下的有机碳矿化特征,分析有机碳矿化对温度变化的响应特征。结果表明：在47d培养期间内,土壤类型和温度对茶园有机碳矿化具有显著影响,并且存在显著的交互作用;相同培养温度条件下高山草甸土茶园有机碳矿化量和矿化速率常数k均显著高于黄壤,但矿化比例差异不显著,随着培养温度的增大,有机碳累积矿化量持续增加,增幅分别为20.90～91.88%（黄壤）和48.52～113.88%（高山草甸土）,且高山草甸土有机碳Q_（10）值高于黄壤,说明有机碳含量丰富的高海拔高山草甸土茶园土壤有机碳温度敏感性更高;低温培养条件下（〈20℃）土壤有机碳矿化的温度敏感性均显著高于高温培养条件下,说明低温条件下有机碳矿化速率对升温更敏感,低温条件下（〈20℃）高山草甸土茶园土壤平均Q_（10）值（2.05）显著高于黄壤（1.66）,但高温条件下（〉20℃）,两者之间没有显著差异;一级动力学方程能较好地描述了2种茶园土壤有机碳的矿化累积动态,土壤有机碳的潜在矿化量（C0）随温度增加而增加。

An incubation test on the yellow and alpine meadow soils collected from the tea plantations in the subtropical region was conducted at 10, 20, and 30℃ to examine the response of the soil organic carbon （SOC） mineralization due to the temperature changes. The results showed that, in a 47 d incubation, both soil type and temperature significantly affected the SOC mineralization with significant interactions between the two factors. At a same incubation temperature, the SOC mineralization accumulation and mineralization constant （k） were significantly higher in the alpine meadow than the yellow soil, but not on the mineralization rate. The cumulative SOC mineralization increased with increasing temperature by 20. 90%-91.88℃ on the yellow soil, and 48. 52%- 113.88% on the alpine meadow soil. The temperature sensitivity, Q10, on SOC of the alpine meadow soil was significantly higher than that of the yellow soil, suggesting a greater effect of climate warming on SOC mineralization for tea plantations at higher altitudes. In addition, Q10 were higher at lower temperatures （〈20℃） than higher temperatures （〉20℃）, indicating that the mineralization was more sensitive to temperature rise at low temperatures. And, when the temperature was lower than 20℃, the sensitivity of the alpine meadow soil was significant higher than that of its counterpart. Whereas, as the temperature raised beyond 25℃, no significant difference was found between them. The dynamics of SOC mineralization appeared to fit a first-order kinetics function, while the SOC mineralization potential （Co） increased with increasing incubation temperature.