Abstract:Air temperature within canopy reflects the growing condition of plants objectively. Simulation of air temperature within canopy can assist in better understanding of microclimate dynamic change characteristics, and can also provide a scientific basis for monitoring late frost injury of winter wheat. A field experiment was conducted in Shangqiu City, Henan Province to observe the winter wheat growth and ambient environmental factors. Based on the localization，coupled WOFOST and SHAW models were applied to simulate dynamic characteristics of air temperature hourly within winter wheat canopy from 0cm to 80cm at after-jointing stage in 2016, and the simulation results were compared with measured data. The results suggested that for coupled WOFOST and SHAW models, model efficiency of the simulated and measured values at different heights within winter wheat canopy was greater than 0.90, and over 75% of absolute errors of simulated values were in the range of -1.5~2.5℃，showing a high accuracy in simulating air temperature within winter wheat canopy as a whole. For daily lowest values of air temperature within winter wheat canopy, model efficiency of coupled WOFOST and SHAW models was about 0.86, and the simulation values of daily lowest values of air temperature within winter wheat canopy were 0.53℃ greater than measured values，showing an excellent conformity between simulated and measured values. And the simulation values could precisely reflect daily lowest values of air temperature below 0℃ within winter wheat canopy where the late frost injury occurred easily. Therefore, coupled WOFOST and SHAW models can simulate air temperature within winter wheat canopy well, increase applicability of SHAW model, and provide a reference for monitoring late frost injury.
