| 摘要: |
| 【目的】探究兴安落叶松天然林土壤N2O通量、土壤温度、土壤湿度昼夜和不同月份的变化特征，进一步阐明土壤温度和湿度对土壤N2O通量的调控机制。【方法】采用便携式N2O/CO CM-919气体分析仪，于2021年生长季（6-9月）对兴安落叶松天然林土壤N2O通量和不同土层（2，10，20 cm）的土壤温度和湿度进行定点连续观测，分析土壤N2O通量对土壤温度和土壤湿度的响应。【结果】（1）兴安落叶松天然林土壤N2O通量呈“夜大昼小”的日变化特征，8月中旬是土壤N2O的“强排放”时期，月平均排放通量为7.67 μg/(m2·h)。（2）当土壤日均温高于15 ℃或昼夜温差较大（2.96~17.22 ℃）时，土壤温度对土壤N2O日排放通量发挥重要影响。当土壤日均湿度低于20%时，土壤N2O通量随湿度增加而增强；当土壤湿度处于20%~30%或增至30%以上时，对土壤N2O通量的抑制作用较明显，湿润环境减弱了N2O的排放。（3）土壤温度和湿度都是影响土壤N2O通量月变化的主要环境因素，并存在显著的交互作用。【结论】在生长季内，兴安落叶松天然林土壤基本是N2O的排放源，10 cm土层土壤温度和湿度对土壤N2O月通量变化影响显著，2 cm土层土壤温度和20 cm土层土壤湿度对土壤N2O日通量变化线性拟合解释率较高。 |
| 关键词: 兴安落叶松天然林 土壤N2O通量 土壤温度 土壤湿度 |
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| 基金项目:国家自然科学基金项目“寒温带兴安落叶松生态系统碳水交换过程与作用机理”（32060262） |
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| Response of soil N2O flux of Larix gmelinii natural forest to soil temperature and moisture |
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JIAN Ya’nan,ZHANG Qiuliang,YANG Jingfu,et al
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| Abstract: |
| 【Objective】This study explored the diurnal and monthly variations of soil N2O flux and soil temperature and moisture in Larix gmelinii natural forest and further clarified the roles of soil temperature and moisture in regulating soil N2O flux.【Method】N2O flux and soil temperature and moisture at different soil layers (2 cm,10 cm and 20 cm) in Larix gmelinii natural forest were continuously observed by a closed-path Los Gatos N2O/CO analyzer (model N2O/CO CM-919) portable gas analyzer during the growing season of June to September in 2021.Then,the response of soil N2O flux to soil temperature and moisture was analyzed.【Result】(1) Diurnally,soil N2O flux in Larix gmelinii natural forest was high at night and low at daytime.Middle August was the strong emission period,and the average emission flux was 7.67 μg/(m2·h). (2) When the daily mean temperature of soil was higher than 15 ℃ or the temperature difference between daytime and night was large (2.96-17.22 ℃),soil temperature plays an important role in the daily N2O emission flux.When the daily mean moisture of soil was below 20%,N2O flux was enhanced with the increase of soil moisture.When the soil moisture was at 20%-30% or increased above 30%,N2O flux was inhibited,indicating that wet environment diminished soil N2O emission. (3) Soil temperature and moisture were the main environmental factors affecting monthly variations of N2O flux,and there were significant interactions.【Conclusion】During the growing season,Larix gmelinii natural forest was basically an emission source of soil N2O.Soil temperature and moisture in 10 cm soil layer had significant influence on monthly flux of N2O,and soil temperature in 2 cm soil layer and soil moisture in 20 cm soil layer had good linear fitting with the daily change of soil N2O flux. |
| Key words: Larix gmelinii natural forest soil N2O flux soil temperature soil moisture |
