青藏高原高寒草甸土壤N_2O排放通量对温度和湿度的响应  

Response of N_2O emission flux to soil temperature and moisture in alpine meadow on Qinghai-Tibetan Plateau

作　　者：杜岩功[1] 周耕 郭小伟[1] 李婧[1] 

机构地区：[1]中国科学院西北高原生物研究,青海西宁810008 [2]山东省威海市农业局,山东威海264200

出　　处：《草原与草坪》2016年第1期55-59,共5页Grassland and Turf

基　　金：国家自然科学基金(31200379;31470530);青海省自然科学基金(2012-Z-921Q)资助

摘　　要：试验采用室内培养的方法研究了青藏高原矮嵩草草甸土壤氧化亚氮(N2O)排放通量对土壤温度和湿度的响应过程。结果表明:随培养温度增加,培养初期矮嵩草草甸土壤N2O排放速率逐渐降低(P<0.05),最高排放速率为4.75±0.24g/(kg·h),最低排放速率仅为2.92±0.19g/(kg·h);而经过7d培养,高寒草甸土壤N2O排放速率先降低,而且转变为弱汇,而后升高,30℃时最高,为0.67±0.06g/(kg·h),各处理均显著低于短期培养时排放速率(P<0.05);随土壤湿度增加,短期培养矮嵩草草甸土壤N2O排放速率先降低随后升高,在土壤湿度为60%时排放速率最高,为(3.62±0.38)g/(kg·h),而在75%时排放速率最低,为(3.38±0.25)g/(kg·h);随着培养时间延长,高寒草甸土壤N2O排放速率逐渐降低,最高排放速率为(0.55±0.32)g/(kg·h);土壤湿度分别为45%和温度为20℃、以及60%和30℃时,1d和7d培养矮嵩草草甸土壤N2O排放速率最高;而在土壤湿度为45%和30℃、以及75%和30℃时,1d和7d培养矮嵩草草甸土壤N2O排放速率最低,后者呈现吸收现象,吸收速率约为-1.84g/(kg·h)。The responses of N2O emission fluxes to soil temperature and moisture of Kobresia humilis meadow were studied in Haibei Station on Qinghai-Tibetan Plateau with culture method in laboratory.It was revealed that the flux decreased gradually with the increase of temperature during the initiate culture phase,and the highest rate was（4.75±0.24）g/（kg·h）.The lowest emission rate was（2.92±0.19）g/（kg·h）.After 7days culture,the N2O flux decreased and became N2O sink,and then increased.The highest flux was（0.67± 0.06）g/（kg·h）at 30℃,but all plots were significant lower than initiate culture（P〈0.05）.Along with the increase of soil moisture,the flux of initiate culture showed a high-low pattern.The lowest value was（3.38± 0.25）g·（kg·h）at 75%and the highest was（3.62±0.38）g/（kg·h）at 60%.Along with the increase of cluture time,the emission rate decreased gradually,and the highest value was（0.55 ± 0.32）g/（kg·h）.The highest emission rates for 1day and 7days culture were reached at 45% soil moisture and 20℃,and 60% soil moisture at 30℃ separately.However,these value dropped to the lowest at 45% soil moisture and 30℃,and75% soil moisture and 30℃.This indicated that the soil N2O emission would decrease under climate warming and precipitation increasing conditions in the future.

关 键 词：土壤温度 湿度 N2O排放 交互作用 高寒草甸 

分 类 号：S812.8[农业科学—草业科学]