【摘要】 利用静态暗箱法在中国科学院新疆巴音布鲁克草原生态站首次对具有代表性的新疆典型性亚高山草甸25年围栏内外土壤CO2日排放进行连续观测。分析了亚高山草甸土壤呼吸变化规律及其影响机制。结果表明,围栏封育后,围栏内土壤CO2日排放总量达到19.117 g.m-2.d-1,围栏外为14.465 g.m-2.d-1,围栏内土壤CO2日排放通量要比围栏外的多了32.16%。浅层土壤土壤温度(包括地表地下5 cm、10 cm土壤温度,p<0.01)与土壤CO2排放通量日变化呈显著正相关性,但15 cm、20 cm和25 cm地温与其无相关性。土壤含水量过低或者过高都会对土壤呼吸有抑制作用,分析发现,土水势在29 kPa~35 kPa时土壤CO2排放通量出现最大值。同时围栏内外土壤CO2排放通量日变化与土水势呈指数相关,其中,围栏内相关系数为0.486 6;围栏外相关系数为0.600 7。更多还原

【Abstract】 Using dark enclosed chamber technique,we measured the daily variation of CO2 flux from the soil for first time at Xinjiang Bayinbuluke Grassland Ecological Station of Chinese Academy of Sciences in the typical subalpine meadow region of Xinjiang,which has been fenced for 25 years.Changes and mechanism of soil respiration in subalpine meadow of Xinjiang were analyzed.The results showed that,after the meadow fenced,CO2 flux is 19.117 g·m-2·d-1 inside and 14.4 650 g·m-2·d-1 outside,and the CO2 flux inside are 32.16% more than that outside.The relationships between the daily variation of CO2 flux from the subalpine meadow soil and soil temperatures at different depths(the 5 cm depth,10 cm depth,P< 0.01) were significant,which could be best described by positive correlation.But the daily variations of CO2 flux from the subalpine meadow soil had no correlation with 15 cm,20 cm and 25 cm depths soil temperature.Excessively low or high soil water content would restrain soil respiration.The results shown that the maximum CO2 flux of the subalpine meadow soil appeared at the 30-35 kPa soil water potential.The relation between the daily variations of CO2 flux from subalpine meadow soil to soil pressure potential could be best described by exponential equations.Correlation coefficient is 0.486 6 inside and 0.600 7 outside.更多还原