淮河流域农田碳收支特征及影响因素分析

采用开路涡度相关系统对淮河流域农田湍流特征进行了4年连续监测,以该地区主要农作物小麦和水稻为例,对CO2通量数据进行分析处理。研究结果表明：农田CO2通量的日变化随季节变化明显,春、夏变化幅度明显大于秋、冬。2007—2010年淮河流域夏季农田CO2通量日变化规律均呈单峰型,白天为明显的碳汇;其日最大累计吸收量出现在2007年,可达16.1mg.m-2.s-1,最小值出现在2009年,为11.1 mg.m-2.s-1。在水稻拔节期垂直风速（W）、潜热通量（LE）、显热通量（H）、光合有效辐射（PAR）、净辐射（Rn）与CO2通量均呈负相关,通过对各项指标进行主成分分析,得到了新的综合指标F=-0.36ZX1＋0.42ZX2＋0.42ZX3＋0.42ZX4＋0.39ZX5＋0.42ZX6＋0.13ZX7,并经过计算得出中午1点是最大的碳汇,凌晨12点是最大的碳源。

The farmland carbon balance characteristics and its influencing factors of the Huaihe River basin

Using the open-path eddy covariance system to Huaihe River basin farmland for turbulence characteristics on a four-year continuous monitoring, For the study of major crops of wheat and rice to analysis and processing the CO2 flux data. The results show that： the farmland diurnal variation of CO2 flux changed significantly with the seasons, the magnitude of changes in spring and summer was significantly greater than the autumn and winter; The diurnal variation of CO2 flux from paddy fields showed a single peak in Huaihe River Basin from 2007-2010, it obviously a carbon converged on daytime; The daily maximum total absorption in 2007, can up to 16.12 mg.m-2 s-1, the minimum in 2009, is 11.16 mg.m-2 s-l; In the jointing stage of rice,vertical wind speed（W）, latent heat flux（LE）, sensible heat flux（H）, Photosynthetic active radiation（PAR）, net radiation（Rn）and CO2 flux have a significant negative correlation; Through principal component analysis by indicators, the new composite indicator F=-0.36ZX1 ＋ 0.42ZX2 ＋0.42 ZX3 ＋0.42 ZX4 ＋0.39 ZX5 ＋0.42 ZX6 ＋0.13 ZX7, and the time in 13：00 is the calculated maximum carbon sinks, 24：00 is the largest carbon source.