西南喀斯特地区四种植物水分生理的初步研究

通过对喀斯特地区的4种植物红背山麻杆、圆叶乌桕、青檀和水冬瓜的水分特征进行测定和比较,结果表明:植物的组织含水量、临界饱和亏缺和需水程度均存在显著差异,其抗旱能力以青檀最强;水分利用效率饱和点以落叶灌木红背山麻杆最高,在600μmol.m-2·s-1左右,光辐射与气孔导度呈对数关系;而三个落叶乔木树种的WUE的光饱和点均在400μmol·m-2·s-1左右,光辐射与蒸腾速率、气孔导度均呈线性极显著相关关系;观测结果没有显示蒸腾饱和现象。

A preliminary study on the water physiology of four plant species in karst area of Southwest China

The water characteristics of Alchornea trewioides,Sapium rotundifolium,Pteroceltis tatarinowii and Sinoadina racemosa were measured and compared in the paper.The results showed that the tissue water content,critical saturation deficit and the water requirement degree were significantly different among the examined four plant species.The drought-resistance of Pteroceltis tatarinowii,a deciduous shrub,was the strongest among them,Alchornea trewioides had the highest WUE saturation point of 600 μmol·m-2·s-1,the PAR was logarithmly correlated with stomata conductance;the LSP of water use efficiency of the three deciduous trees species was all at 400 μmol·m-2·s-1.The PAR was significantly correlated with transpiration and the stomata conductance,and no transpiration saturation phenomenon in the four plant species was observed.