摘要
应用基于生理生态学过程的EALCO模型,对玉米农田生态系统的蒸散(ET)过程进行了模拟,在模型检验基础上,使用该模型模拟了玉米农田生态系统ET过程对未来气候变化的响应。结果表明,EALCO模型中能量与水过程的动态耦合机制使模型能够较好地模拟农田蒸散过程,基于涡度相关法的观测值与模型模拟值在小时、日尺度上均吻合较好,模型可以解释67%的日蒸散的变化特征。对土壤蒸发与冠层蒸腾的分别模拟显示,生长季土壤蒸发约占ET的36%。温度的升高会引起ET与冠层蒸腾的增加,同时土壤蒸发减少;ET对降水减少的响应较为敏感,主要表现在土壤蒸发的下降。大气CO2浓度升高对冠层蒸腾影响显著,该情景下冠层蒸腾下降幅度最大。研究所假设的2100年气候情景下,该农田生态系统生长季蒸散将减少,然而相对于降水的减少而言,蒸散的减少量较小,即水分支出项相对增加,因此,发生土壤水分匮乏的可能性加大,这可能会加剧该地区的暖干化趋势,给作物产量及生态环境带来威胁。
A process-based physiological model,EALCO（Ecological Assimilation of Land and Climate Observation）,was used to simulate the evapotranspiration from maize cropping system and to investigate the responses of evapotranspirational processes to projected climate change.Measured evapotranspiration from the maize cropping system by an eddy covariance system was used to test the model′s performance.The results showed that EALCO has high capability to simulate the evapotranspiration in both hourly and daily scales,and explained 67% of daily evapotranspiration.By dividing the evapotranspiration into soil evaporation and canopy transpiration in growing season,simulated soil evaporation counted for 36% of evapotranspiration.Simulated evapotranspiration and canopy transpiration will increase due to the increase in air temperature,but soil evaporation tends to decrease.Simulated evapotranspiration was strongly sensitive to the decrease in precipitation,which mainly leads to the decrease in soil evaporation.The increase in atmospheric CO2 concentration will significantly decrease canopy transpiration.Under the scenarios of future climate change in 2100,the model suggested that the evapotranspiration during the growing season will decrease;however,the decreased evapotranspiration can not compensate the decease in precipitation.As a consequence,future climate change will increase the possibility of crop water stress,intensify the trends of warming and drying,and hence threaten crop production and ecological environment in the studied region.
出处
《生态学报》
CAS
CSCD
北大核心
2010年第3期698-709,共12页
Acta Ecologica Sinica
基金
中国气象局气候变化专项资助项目
中国气象局业务建设重点资助项目
中央级公益性科研院所基本科研业务费专项资助项目
