| 引用本文: | 阚飞,岳宁,丁林凯,等.不同气象条件下陇中玉米农田生态系统水分利用效率研究[J].灌溉排水学报,2018,37(10):116-122. |
| KAN Fei,YUE Ning,DING Linkai,et al.不同气象条件下陇中玉米农田生态系统水分利用效率研究[J].灌溉排水学报,2018,37(10):116-122. |
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| 摘要: |
| 【目的】探究陇中半干旱区玉米农田生态系统水分利用情况。【方法】利用陇中半干旱区玉米农田生态系统，涡度系统碳水通量数据，分别从生态系统水分利用效率（WUE）、固有水分利用效率（IWUE）探讨了不同气象条件对半干旱区玉米农田生态系统水分利用效率的影响。【结果】WUE和IWUE在生长季均值分别为4.71 g/kg和32.04 （g·hPa）/kg。IWUE考虑了饱和水汽压差（VPD）对蒸散量（ET）的非线性影响，GEP与ET在日尺度上存在滞后效应，而IWUE能有效地减弱滞后效应。阴晴天的光合有效辐射、饱和水汽压差、液流速率、蒸散量均为单峰曲线，晴天的值大于阴天的。阴晴天的碳通量变化不明显，水分利用效率为“U”型曲线，阴天的碳通量大于晴天的。阴天饱和水汽压差和液流速率与WUE的线性相关关系均较差，晴天的饱和水汽压差和液流速率与WUE的相关关系较阴天好，而IWUE的拟合效果好。【结论】与WUE相比，IWUE能更好地评价该地区碳水耦合情况。 |
| 关键词: 陇中； 农田生态系统； 水分利用效率； 固有水分利用效率 |
| DOI：10.13522/j.cnki.ggps.20170034 |
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| Water Use Efficiency of Maize Agroecosystem in Longzhong Region under Different Weathers |
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KAN Fei， YUE Ning， DING Linkai， LI Ling， WEI Guoxiao
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School of Earth and Environmental Science, Lanzhou University， Lanzhou 730000, China
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| Abstract: |
| 【Objective】 Agricultural production and ecosystem functions depend on weather. The purpose of this paper is to put some insight into the water use of a semi-arid maize agroecosystem in Longzhong region. 【Method】 Carbon and water fluxes measured from the eddy covariance were applied to estimate the water use efficiency (WUE) and inherent water use efficiency (IWUE) of the agroecosystem. The responses of WUE and IWUE to different weathers were analyzed. 【Result】 The relationship between gross ecosystem productivity (GEP) and evapotranspiration (ET) was not as strong as the relationship between GPP·VPD and ET, because the nonlinear effect of the vapor pressure deficit (VPD) on ET in the latter was taken into account. The time lag between GEP and ET resulted in a hysteresis curve, and IWUE reduced the effect of this hysteresis. Photosynthetically active radiation (PAR), VPD, flow rate and ET can be fitted into a single-peak curve for both sunny and cloudy days, with the associated values in sunny days larger than that in cloudy days. The variation of the net ecosystem CO2 exchange (NEE) was similar in sunny and cloudy days, and the water use efficiency was in a U-shaped curve with the corresponding value for cloudy days larger than that for sunny days. 【Conclusion】 The dependence of WUE on VPD and the flow rate in cloudy days are not as good as that in sunny day because of the disturbance of vapor. IWUE can improve the correlation coefficient. Compared to WUE, IWUE is more appropriate to describe water and carbon interaction in this area. |
| Key words: Longzhong; agroecosystem; water use efficiency; inherent water use efficiency |
