作 者：
徐同庆;徐宜民;孟霖;胡海洲;王程栋;周立新;刘光亮;董建新;陶健
单 位：
中国农业科学院烟草研究所;中国农业科学院研究生院;湖南中烟工业有限责任公司
关键词：
烟田生态系统;水、碳通量;非对称响应;攀西干热河谷
摘 要：
为研究关键环境因子与烟田生态系统水、碳通量日间变化之间的响应关系。基于2016年攀西干热河谷典型烟田生态系统烤烟成熟初期涡度相关通量观测数据,分析了典型晴天内烟田冠层导度及水、碳通量的日间变化规律及其对气温、VPD和净辐射日间变化的非对称响应特征。结果表明:研究区烟田生态系统CO_2通量和蒸散量(ET)均存在明显的"午休"现象,冠层导度的变化是影响烟田水、碳通量日间变化的直接因素;研究区烤烟成熟初期水、碳通量呈现显著的非对称响应特征,相同的净辐射强度下,下午的CO_2通量和ET值均明显高于上午;WUE对净辐射的响应特征与净辐射强度有关,当净辐射强度小于230W·m~(-2)时,下午烟田WUE大于上午,反之,上午烟田WUE大于下午;气温、饱和水气压差(VPD)与净辐射在日间的非同步变化是导致烟田冠层导度和ET在日间非对称响应的主要气象因素,从而间接影响烟田水、碳通量及WUE的日间动态特征。本研究为进一步分析攀西干热河谷烟田水、碳通量季节与年际变化特征及相关变异机理提供了理论依据与数据支持。
译 名：
Asymmetric response character of diurnal variation of water and carbon fluxes at initial mature stage of flue-cured tobacco in Panxi dry and hot valley tobacco planting area
作 者：
XU Tongqing;XU Yimin;MENG Lin;HU Haizhou;WANG Chengdong;ZHOU Lixin;LIU Guangliang;DONG Jianxin;TAO Jian;Tobacco Research Institute, Chinese Academy of Agricultural Sciences;Graduate School, Chinese Academy of Agricultural Sciences;China Tobacco Hunan Industrial Co., Ltd.;
关键词：
tobacco field ecosystem;;water-carbon flux;;asymmetric response;;Pan-xi dry and hot valley
摘 要：
Investigating asymmetric-response characteristics of diurnal water-carbon flux in tobacco field ecosystem is helpful to evaluate relationships between key environmental factors and water-carbon flux. Based on flux observation data during initial mature stage in Pan Zhihua-Xi Chang(Pan-xi) dry and hot valley tobacco planting area, the diurnal dynamic of canopy conductance and water-carbon flux and their asymmetric responses to environmental factors were explored. Results showed that water-carbon flux had a midday depression during initial mature stage, and change of canopy conductance was the direct factor affecting diurnal dynamic of water-carbon flux. Under the same net radiation intensity, CO_2 flux and ET were significantly higher in the afternoon than in the morning, while the response of WUE to net radiation was related to the intensity of net radiation: when net radiation was less than 230W·m~(-2), the WUE was higher in the afternoon; when net radiation was greater than 230 W·m~(-2), the WUE was higher in the morning. The asynchronous change between air temperature, VPD and net radiation was the main meteorological factors leading to the asymmetry distribution of canopy conductance and ET in the morning and afternoon. Thus, the dynamic characteristics of water-carbon fluxes were indirectly affected. Through exploration of nonsymmetrical response characteristics of water-carbon flux to environmental factors, the study can provide theoretical basis and data support for further analysis on water-carbon flux and its driving mechanism in Pan-xi dry and hot valley tobacco planting area.
