摘要
采用涡动相关技术对2009,2010和2011年疏勒河上游高寒草甸生态系统CO2通量观测和分析表明,疏勒河上游高寒草甸生态系统CO2通量具有明显的日变化和年变化特征,6月、7月和8月为CO2的强吸收期,4月、5月和10月为CO2的强释放期。计算得到3年的CO2净吸收量分别为134.5,151.3和194.4g CO2/m2,平均吸收量为160.0g CO2/m2,在区域起着碳汇的作用。生长季节,净生态系统交换量(net ecosystem CO2exchange,NEE)与温度、降水量、相对湿度以及地表长波辐射呈负相关,气温在0～7℃范围内NEE随气温增加线性减小,当温度大于7℃时,NEE随温度的增加而增大;非生长季节,NEE与温度、降水量、相对湿度以及地表长波辐射呈正相关。当地表反射率在0.2左右,NEE呈现快速增长趋势,当反射率超过0.3时,NEE接近最大值,并保持稳定。
An eddy covariance observation system was established for providing continuous measurements on CO_2 fluxes in an alpine meadow ecological system at the upper reach of the Shule River Basin from 2009 to 2011. Obvious seasonal and inter-annual variations of CO_2 flux were observed. The months, June, July and August, were the strongest absorption period for CO_2 while April, May and October were the strongest release period for CO_2. The net exchange of CO_2 in the three years was 134.5, 151.3 and 194.4 g CO_2/m2, respec tively, and the mean value was 160.0 g CO_2/m2. This indicates that the alpine meadow system played an im portant role as a carbon sink. During the growing season, the correlations between CO_2 net exchange and the temperature, precipitation, relative humidity, and surface long wave radiation were all negative. When the temperature was higher than 7℃, the CO_2 net exchange increased as temperature increased. In the dormant season, the correlations between CO_2 net exchange and the temperature, precipitation, relative humidity, and surface long wave radiation were all positive. When the surface reflectivity was about 0.2, the trend of the CO_2 net exchange increased fast. When the surface reflectivity was more than 0.3, the CO_2 net exchange reached a maximum and then remained stable.
出处
《草业学报》
CSCD
北大核心
2013年第4期18-26,共9页
Acta Prataculturae Sinica
基金
国家重大科学研究计划(2013CBA01806)
国家科技支撑计划课题(2013BAB05B03)
甘肃省自然科学基金(1107RJZA1711)
国家自然科学基金(41271079)资助
关键词
涡动相关
高寒草甸
气象因子
疏勒河上游
eddy covariance alpine meadow meteorological factor the upper reach of Shule River
