单次降水对高寒草地温室气体通量昼夜变化的影响研究

在全球变化背景下,青藏高原降水格局发生改变,并影响高寒草地温室气体排放.为了更好地认识降水变化与高寒草地温室气体排放的关系,在2015年7月24日,通过人工降水6.7 mm,研究了单次降水对高寒草地温室气体昼夜变化的影响.表明:(1)单次降水没有改变土壤温度,但显著增加了土壤湿度;(2)单次降水后24小时内,高寒草地CH4吸收量降低了2.46倍,CO2和N2 O排放量分别提高15.3%和98.9%;(3)单次降水弱化了高寒草地CH4和N2 O排放量与土壤温度的关系.

Effects of Single Precipitation on Diurnal Variation of Greenhouse Gas Fluxes from Alpine Grassland

Under the background of global change, the precipitation patterns in the Qinghai-Tibetan Plateau are changing, which will affect the greenhouse gas emissions from alpine grassland ecosystem. In order to better understand the relationshipbe-tween precipitation patterns andalpine grassland greenhouse gas emissions, one study was conductedon July 24,2015 and through artificial precipitation 6. 7 mm,to research the effects of single precipitation event on greenhouse gas fluxes diurnal variation from alpine grassland in the Qinghai-Tibetan Plateau. The results showed:( i) single precipitation didn't change soil temperature, but significantly increased the soil moisture;( ii) within 24 hours after single precipitation, the alpine grassland absorbability of CH4 decreased by 2. 46 times, but CO2 and N2 O emissions increased by 15. 3% and 98. 9%, respectively;( iii) single precipitation e-vent weakened the relationship between alpine grassland CH4 and N2 O fluxes and soil temperature.