摘要
气孔控制着光合作用和蒸腾作用两个相互耦合的过程,气孔导度与光合速率的耦合关系是理解陆地生态系统碳循环和水循环及其耦合关系的基础。利用LI-6400光合仪控制光强和CO2浓度变化,分析了C3和C4作物气孔导度-光合速率耦合关系的差异。结果表明:即使CO2浓度变化条件下,Ball-Berry模型也能很好地模拟气孔导度与光合速率二者的耦合关系。气孔导度与净光合速率之间的耦合系数体现了不同作物之间水-碳交换比例的差异,反映了气孔限制和内部生理生化过程限制在不同作物上所占的比例。由于该系数在C3作物和C4作物之间存在明显差异,C3作物中,陆生C3作物和水生C3作物也存在一定差异,因此作物的生态功能类型可以大体划分为3类:C4作物、陆生C3作物和水生C3作物。这种生态功能类型的划分为提高碳循环、水循环以及水碳耦合循环模型在区域尺度上应用的精度是有益的。
The coupled processes of leaf photosynthesis and transpiration are controlled by stomotal, and the relationship between stomotal conductance and photosynthesis rate is the basis of understanding carbon and water cycle in terrestrial ecosystem. The differences in the relationship between stomotal conductance and photosynthesis rate in C3 and C4 plant species were studied under controlled light density and CO2 concentration by LI-6400 Portable Photosynthesis System. The results showed：Ball-Berry model can reasonably simulate the relation between stomotal conductance and photosynthesis rate even under various CO2 concentration conditions. The coefficient between stomotal conductance and photosynthesis rate revealed the difference in the ratio of water-carbon exchange, and in the limitations of stomotal and inter physiochemical processes between the different crop types. Because obvious differences in the coefficient between stomotal conductance and photosynthesis rate were found between C3 and C4 crops, and between terricolous and aquicolous C3 crops, the crop ecotype can be generally distinguished three types： C4, terricolous and aquicolous C3 crops. The differentiation of crop ecotype will improve the accuracy in modeling carbon and water cycle in regional scale.
出处
《华北农学报》
CSCD
北大核心
2008年第1期71-74,共4页
Acta Agriculturae Boreali-Sinica
基金
国家杰出青年基金(30225012)
山东省中青年科学家奖励基金(2005BSB01177)
