%0 Journal Article
%T Water-carbon coupling modeling of summer maize at the leaf and canopy scales
%A BaoZhong Zhang
%A Yu Liu
%A Di Xu
%A JiaBing Cai
%A Zheng Wei
%J Chinese Science Bulletin
%@ 1861-9541
%D 2013
%I 
%R 10.1007/s11434-012-5630-0
%X Transpiration and photosynthesis are two closely related and intercoupled processes that dominate the physiological activities and yield of crops. Therefore, there is a need to study water-carbon coupling modeling at various scales to increase water use efficiency (WUE). Using a summer maize field in North China as an example, the variations in leaf and canopy photosynthesis and transpiration (or evapotranspiration) were analyzed. The synthetic model of photosynthesis-transpiration based on stomatal behavior (SMPT-SB) was then calibrated and validated at the two scales. The leaf photosynthesis and transpiration, as well as the canopy photosynthesis and evapotranspiration, have a consistent diurnal trend. However, the canopy evapotranspiration is affected more by topsoil moisture content. The regression coefficient between leaf photosynthesis, transpiration, and WUE estimated by the SMPT-SB and the measured values was found to approach 1, with a coefficient of determination of more than 0.74. The relative error between the two sets of values is less than 11%. Therefore, the SMPT-SB could express fairly well leaf photosynthesis, transpiration, and WUE. The estimated canopy-scale photosynthesis by the SMPT-SB is also in good agreement with the measured values. However, this model underestimates the canopy evapotranspiration when the topsoil has high moisture content and therefore overestimates, to a certain extent, the canopy WUE.
%K photosynthesis
%K transpiration
%K water use efficiency
%K SMPT-SB
%K stomatal conductance
%K maize
%U http://link.springer.com/article/10.1007/s11434-012-5630-0