乌兰乌苏绿洲棉田生态系统水汽和二氧化碳通量研究

为了研究新疆干旱和半干旱地区农田生态系统陆地-大气间水汽和二氧化碳连续相互作用对全球气候、环境变化的影响。2009年1—12月应用涡动相关系统，连续观测乌兰乌苏绿洲棉田生态系统下垫面（裸地和不同生长期）地气界面水汽和二氧化碳通量变化，分析水汽和二氧化碳通量的季节和日变化规律。结果表明：（1）绿洲棉田生态系统下垫面全年二氧化碳通量变化分干、湿2季，干季棉田下垫面以释放CO2为主，湿季以吸收CO2为主，但全年吸收量远大于释放的量。（2）在湿季，绿洲棉田生态系统下垫面其CO2的通量值曲线呈开口向上的抛物线型，与下垫面棉田发育情况有较好的相关性。（3）其水汽通量全年分3个阶段，水汽通量值从小到大分别为：雪覆盖阶段。裸地阶段。棉花种植阶段。（4）在湿季，其水汽通量日变化明显，与日照强度和温度相关较好。

Study on Fluxes of CO2 and Water Vapor of Oasis Cotton Ecosystem in Wulanwusu

In order to study the effects of global climate change between carbon dioxide continuous interaction and water vapour of the farmland ecosystem in arid and semi-arid region, during January 2009 to December 2009, applying eddy covariance system (EC) continuous observing the variations of water vapor flux and CO2 flux at the atmosphere land interface of underlying surface (bare soil and different growth periods) of cotton field ecosystem in Wulanwusu, the author analyzed the seasonal and diurnal variations of water vapor flux and CO2 flux. The results showed that: (1) the annual CO2 flux of the underlying surface of oasis cotton ecosystem was divided dry and wet seasons, the underlying surface of cotton field absorbs CO2 mainly in dry season, wet season to release the CO2 mainly, but the annual uptake was much larger than the amount released. (2) In the wet season, CO2 fluxcurve of the underlying surface of oasis cotton field ecosystem showed upward opening parabola, was better correlative to the underlying surface cotton field development. (3) Water vapor flux of the underlying surface of oasis cotton field ecosystem was segmented into 3 phases yearly, according to water vapor flux from small to large phases were separated to the covered with snow stage, the bare soil stage and the cotton-growing stage. (4) In the wet season, the diurnal variation of water vapor flux of the underlying surface of oasis cotton ecosystem was obvious, was better bound up with sunshine intensity and temperature.