兴安落叶松天然林土壤N_(2)O通量对土壤温度和湿度的响应  

Response of soil N_(2)O flux of Larix gmelinii natural forest to soil temperature and moisture

作　　者：菅亚男 张秋良[1,2] 杨競夫 关蕾 黄明儒 张泽 张永亮 孙长磊 JIAN Ya’nan;ZHANG Qiuliang;YANG Jingfu;GUAN Lei;HUANG Mingru;ZHANG Ze;ZHANG Yongliang;SUN Changlei(Forestry College,Inner Mongolia Agricultural University,Hohhot,Inner Mongolia 010019,China;Forest Ecosystem National Observation and Research Station of Daxing’anling,Genhe,Inner Mongolia 022350,China)

机构地区：[1]内蒙古农业大学林学院,内蒙古呼和浩特010019 [2]内蒙古大兴安岭森林生态系统国家野外科学观测研究站,内蒙古根河022350

出　　处：《西北农林科技大学学报（自然科学版）》2023年第9期101-108,118,共9页Journal of Northwest A&F University(Natural Science Edition)

基　　金：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)。

摘　　要：【目的】探究兴安落叶松天然林土壤N_(2)O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N_(2)O通量的调控机制。【方法】采用便携式N_(2)O/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N_(2)O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N_(2)O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N_(2)O通量呈“夜大昼小”的日变化特征,8月中旬是土壤N_(2)O的“强排放”时期,月平均排放通量为7.67μg/(m^(2)·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N_(2)O日排放通量发挥重要影响。当土壤日均湿度低于20%时,土壤N_(2)O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N_(2)O通量的抑制作用较明显,湿润环境减弱了N_(2)O的排放。(3)土壤温度和湿度都是影响土壤N_(2)O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N_(2)O的排放源,10 cm土层土壤温度和湿度对土壤N_(2)O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N_(2)O日通量变化线性拟合解释率较高。【Objective】This study explored the diurnal and monthly variations of soil N_(2)O flux and soil temperature and moisture in Larix gmelinii natural forest and further clarified the roles of soil tempera-ture and moisture in regulating soil N_(2)O flux.【Method】N_(2)O 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 N_(2)O/CO analyzer(model N_(2)O/CO CM-919)portable gas analyzer during the growing season of June to September in 2021.Then,the response of soil N_(2)O flux to soil temperature and moisture was analyzed.【Result】(1)Diurnally,soil N_(2)O 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 7.67μg/(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 N_(2)O emission flux.When the daily mean moisture of soil was below 20%,N_(2)O flux was en-hanced with the increase of soil moisture.When the soil moisture was at 20%-30%or increased above 30%,N_(2)O flux was inhibited,indicating that wet environment diminished soil N_(2)O emission.(3)Soil tem-perature and moisture were the main environmental factors affecting monthly variations of N_(2)O flux,and there were significant interactions.【Conclusion】During the growing season,Larix gmelinii natural forest was basically an emission source of soil N_(2)O.Soil temperature and moisture in 10 cm soil layer had signifi-cant influence on monthly flux of N_(2)O,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 N_(2)O flux.

关 键 词：兴安落叶松天然林 土壤N_(2)O通量 土壤温度 土壤湿度 

分 类 号：S791.222[农业科学—林木遗传育种]