摘要
温室气体大量排放使得全球变暖已成为世界公认的热点问题之一。农田生态系统在全球碳循环与碳平衡中扮演着重要的角色。文中运用开路式涡度相关测量系统进行定点定位观测,研究干旱区农田生态系统/大气间净交换量(Net Ecosystem Exchange),分析农田生态系统中碳源/汇功能的关系。结果表明:新疆棉田生态系统在现蕾期、开花期与铃期CO_2通量日变化呈现出单峰型的"U"型曲线,现蕾期、开花期和铃期CO_2通量最高点在凌晨3:00、4:00和1:00,分别为9.45、8.78和7.68umol·m^(-2)·s^(-1),CO_2通量最低点在正午14:00、15:00和15:00,依次为-19.35、-21.73和-20.51umol·m^(-2)·s^(-1)。不同生育期夜晚NEE值均负值,表明棉田生态系统夜间处于碳排放过程;白天正值,棉田生态系统为碳吸收过程。棉花不同生育期均为碳储存,且开花期碳储量最大,平均值为-7.26g·m^(-2)·d^(-1),其次是现蕾期,平均值为-6.31g·m^(-2)·d^(-1),铃期平均值为-5.37g·m^(-2)·d^(-1)。温度和降雨对棉田生态系统碳储量影响显著。研究结果表明干旱区高产棉田生态系统有着较好的碳储量,是一个碳汇过程。
Greenhouse gas cause the global warming has become a big problem in the world. Farmland ecosystem play an important role in carbon cycle and carbon balance. In this research we used the Open Eddy Covariance to do an insitu observation, and did some research about NEE （Net Ecosystem Exchange）, analyzed the relationship between carbon source and sink of farmland ecosystem. The results showed that in cotton field ecosystem the NEE variations were the U -shape curve in budding stage, flowering stage and bolling stage; the biggest NEE appeared at 3：00 AM, 4：00AM and 1：00AM for budding stage, flowering stage and bolling stage, and there were 9.45umol ·m^-2 · s^-1 8.78umol · m^-2 · s^-1 and 7.68umol · m^-2 · s^-1 . the lowest NEE appeared at 14：00 PM ,15：00PM and 15：00PM, there were -19.35umol · m^-2· s^-1 -21.73umol · m^-2 · s^-2 and - 20.51umol · m^-2 · s^-1 The NEE value was negative at night, it showed the cotton fields ecosystem was in the carbon emissions; during the day NEE value was positive, it showed that the cotton fields ecosystem was in the carbon absorption. NEE variation was a ＂ U＂ type curve for a month, but the change was not big. The three growing stages were all for the carbon storage; the carbon storage in flowering stage was the largest（ -7.26g · m^ -2· s^-1）, next was in budding stage （ -6.31g·m ^-2· s^-1 ）, and the boiling stage （-5.37g· m^-2· s^-1 ）. Temperature and rainfall had an obvious effect for carbon storage. In arid area＇s agricultural ecosystem the carbon storage was obviously a process of carbon sink.
出处
《干旱区资源与环境》
CSSCI
CSCD
北大核心
2016年第7期59-64,共6页
Journal of Arid Land Resources and Environment
基金
教育部科学技术研究项目(213039A)
国家自然科学基金(31360320)
国家科技支撑项目(2014BAC14B03)资助
关键词
棉田生态系统
NEE
碳汇
涡度相关
cotton field ecosystem
NEE
carbon storage
Open Eddy Covariance
