摘要
为深入认识高寒草甸温室气体通量对长期气候变暖的响应,利用开顶式生长室(OTC,Open Top Chamber)模拟增温2a(2Y,2015-2016年)和6a(6Y,2011-2016年)对藏北高寒草甸生长季CO_2、CH_4和N_2O通量的影响。结果表明:与对照相比,生长季(6-8月)增温6Y处理和增温2Y处理分别增加和降低高寒草甸土壤CO_2排放通量,其中7月增温6Y处理CO_2排放通量显著高于增温2Y处理;增温6Y和2Y处理增加了高寒草甸CH_4吸收通量,但是处理间差异均不显著;高寒草甸N_2O排放通量表现为增温6Y>2Y>CK,处理间无显著差异。环境因子与温室气体排放通量的相关分析表明,CO_2、CH_4和N_2O排放通量与0~5cm土壤温度相关不显著;土壤湿度、植物地上生物量、微生物生物量碳和蔗糖酶是影响高寒草甸CO_2排放通量的关键因子;NO_3^--N是影响CH_4吸收通量的关键因素;脲酶和NO_3^--N是影响N_2O排放通量的主要因子。因此,增温6Y处理通过增加植物地上部生物量、蔗糖酶活性,从而提高了土壤CO_2排放通量,增温6Y和2Y处理通过增加土壤脲酶和NO_3^--N含量,从而促进了土壤N_2O排放和CH_4的吸收通量。
To explore the effects of long-term climate warming on greenhouse gases（GHGs） flux in the alpine meadow,the simulated warming 2 years（2Y,2015-2016） and 6 years（6Y,2011-2016） experiments were conducted by the open top chamber（OTC） in an alpine meadow of Tibetan Plateau,then the dynamics of CO2,CH4 and N2O fluxes were measured during growing season.The observations showed that the CO2 flux during growing season was increased with 6Y and decreased with 2Y warming treatment,respectively,compared with the control.And the CO2 flux with 6Y warming treatment was significantly higher than that of 2Y treatment in July.The CH4 absorption flux was increased with 6Y and 2Y warming treatment,but the differences between treatments were not significant in the growing season.The N2O emission flux was showed 6Y〉2Y〉CK in the growing season,and the differences between treatments were not significant.The relationship between environmental factors and GHGs flux were analyzed by using of correlation analysis.The relationship between CO2,CH4 and N2O fluxes and soil temperature（0-5 cm） was not obvious.The soil moisture,aboveground biomass,microbial biomass carbon and invertase were key factors regulating the CO2 fluxes,NO3--N was mainly factor affecting the CH4 absorption flux,and NO3--N and soil urease were the main factors promoting N2O emission flux.Therefore,the CO2 flux was promoted by increasing plant biomass and invertase activity with 6Y warming treatment,and the N2O emission and CH4 absorption flux were improved by increasing the soil urease and NO3--N content with 6Y and 2Y warming treatment.
出处
《中国农业气象》
CSCD
北大核心
2018年第3期152-161,共10页
Chinese Journal of Agrometeorology
基金
博士后科学基金(157148)
国家自然科学基金(青年)(31600366)
国家重点研发计划课题(2016YFC0502003)
关键词
温室气体排放
OTC增温
高寒草甸
酶活性
土壤养分
Greenhouse gases emission
OTC warming
Alpine meadow
Enzyme activity
Soil nutrients
