SPAC系统中的水热CO_2通量与光合作用的综合模型(Ⅰ)模型建立

本文建立了模拟农田SPAC (Soil Plant AtmosphereContinuum)系统中土壤水分动态 ,蒸发蒸腾、CO2 通量和光合作用的模型 .模型包括土壤水流子模型 ,根系吸水子模型 ,蒸发蒸腾子模型 ,冠层阻力 -光合作用 -CO2 通量子模型几个组成部分 .土壤水流子模型采用土壤水流的连续方程来描述 ;根系吸水子模型采用了根据Feddes模型改进得到的模型 ;蒸发蒸腾子模型采用Shuttleworth Wallace公式 ;采用叶片水平的气孔阻力 光合作用模型 ,并将其扩展到冠层尺度来确定冠层阻力、光合作用速度以及叶片气孔下腔的CO2 浓度 ,并进而确定冠层的CO2 通量 .本模型的特点是尽可能采用简便的处理方法来描述SPAC系统中的水、热、CO2 传输过程与光合作用过程 ,同时各个子模型又具有较强的机理性 .

An integrated model for water heat CO_2 flux and photosynthesis in SPAC system I.Establishment of model

An integrated model for simulating the interaction among soil water dynamics,soil evaporation and crop transpiration,CO-2 flux as well as the photosynthesis in SPAC is established in this paper.In the model,soil profile is divided into adjacent compartments and the soil water dynamics is modeled with sets of water balance equations.Crop water uptake by root is modeled with a modified version of Feddes model.The soil evaporation and crop transpiration are calculated according to the Wallace formula.Two schemes for canopy resistance modeling are proposed.In the first scheme,canopy resistance and photosynthesis are modeled by scaling up leaf|scale model suggested by the authors.In the another scheme,Dickinson's canopy resistance model is proposed when it is not required to or the data are not enough to estimate the photosynthesis and CO-2 flux.