水分条件对巴音布鲁克高寒湿地CO_2排放的影响

Impacts of water condition on CO_2 emissions in Bayinbuluke Marsh Meadow

在新疆天山中部巴音布鲁克天鹅湖高寒湿地,以苔草(Carex tristachya)为主要建群种的样地为研究对象,利用英国PP-systems公司生产的便携式土壤呼吸测定系统(CIRAS-2-SRC)研究了不同地表水分条件对天鹅湖高寒湿地夏季土壤CO2排放的影响。结果表明,1)湿润区的生物量大于干燥区;干燥区土壤CO2排放高于湿润区,干燥区土壤CO2排放日变化曲线为单峰曲线,CO2排放最高点出现在当地14:00-16:00,最高值为1.185 0g CO2·m-2·h-1;湿润区土壤CO2排放日变化曲线为双峰曲线,两个峰值分别出现在12:00和16:00,最高值为1.024 0g CO2·m-2·h-1。2)不同水分条件下生物量中凋落物含量影响土壤CO2排放。土壤温度是CO2排放的主要限制因子,且地表干燥区CO2排放与土壤温度的相关性更显著(P<0.01)。土壤湿度与CO2排放相关性不显著(P湿润区=0.997,P干燥区=0.409)。

The CO2 emission in Carex tristachyaalpine wetland with different water conditions in Bayinbuluke Swan Lake,Xinjiang Tianshan Central in summer were measured with portable soil respiration measurement system(CIRAS-2-SRC)made by British PP system company.The results showed that the biomass of humid area was greater than that of the drying area.The CO2 emission of drying area was higher than that of the wet area.The diurnal variation curve of CO2 emission from dry area was unimodal curves with the highest points occurred between 14:00and 16:00(1.185 0g CO2·m-2·h-1).The diurnal variation curve of CO2 emission from wet area were bimodal curves with the highest points occurred at 12:00and 16:00,respectively,and the highest value was 1.024 0g CO2·m-2·h-1.The litter content of biomass had effects on soil CO2 emissions under different water conditions,however,soil temperature was the major limiting factor for CO2 emissions.CO2emissions had a significant positive correlation with surface soil temperature in the dry area(P<0.01)and did not have significant positive correlation with soil humidity(Pwet area=0.997,Pdry area=0.409).