降水对青藏高原高寒灌丛冷季CO_2通量的影响

Effect of Precipitation on Clod Season CO_2 Flux of Alpine Shrub on Qinghai-Tibetan Plateau

利用涡度相关系统CO2通量观测数据,分析了青藏高原高寒灌丛生态系统冷季CO2通量对降水事件的响应（以2003～2005年10月和11月份为例）。结果表明：在降水事件过后的较短时间尺度内,青藏高原高寒灌丛生态系统CO2通量会显著增加,而且增加量明显大于降水前平衡态下的正常波动值;一般经过较长的无降水时间段后的降水会显著促进土壤呼吸,从而使高寒灌丛生态系统CO2通量明显增加。

Based on the continuous CO2 flux observation with eddy covariance system conducted in the alpine shrub on the Qinghai-Tibet Plateau, the relationship between CO2 flux and precipitation was analyzed according to data of October and November in 2003, 2004 and 2005. The results shown that after individual rain events the large pulses of CO2 flux were observed over the alpine shrub ecosystem during October and November, and the increase exceeded normal variations under the former balance, evidently. The precipitation after longer dry period distinctly facilitate soil respiration, consequently, the CO2 flux over the alpine shrub markedly increased after the occurrence of precipitation during October and November.