乌兰布和沙漠东北部不同起源的5种沙生灌木的光合及生长特性

在乌兰布和沙漠地区,研究了中沙冬青、梭梭、白刺、霸王、柠条等5种沙生灌木的生理生长指标的差异性,结果表明:这些灌木树种的净光合速率、气孔导度、蒸腾速率、水分利用效率等气体交换特征和株高、地径、冠幅等生长指标在不同起源之间均具有显著差异,且人工起源植株的气体交换特征均比天然起源植株的大,而生长指标则均比天然起源植株的小;天然林和人工林中不同树种的水分利用效率的差异均不显著,但不同树种的净光合速率、气孔导度、胞间CO2浓度、蒸腾速率等气体交换特征和株高、地径、冠幅等生长指标差异却很显著.在测定光响应曲线和CO2响应曲线基础上求算出的最大光合速率、表观量子效率、光补偿点、光饱和点、暗呼吸速率、CO2补偿点和羧化效率等光合响应曲线参数在不同树种以及不同起源之间的变化也很大,并据此提出不同树种的人工林栽培及天然林保护措施.

The D ifferences of Growth and Photosynthetic Tra its of Five Shrubs Spec iesfrom Two Or ig ins in the Northea stern Ulanbuh Desert

Five dominant species of natural and artificial-origins shrubs in the northeastern Ulanbuh Desert,Amm opiptan thus m ongolicus, Ha loxy lon amm odend ron, N itraria tangu torum, Zygophy llum xanthoxylum, Caraganakorsh insk ii, were chosen for the research. The photosynthetic gas exchange indices, photosynthetic response curvesand growth indiceswere measured. The differences among different species and originswere analyzed. The ANOVAresults showed that between natural and artificial origins, the remarkable differences exist in the gas exchangeindices, net photosynthetic rate ( Pn ) , stomatal conductance ( Gs ) , transp iration rate ( E ) , water utilizationefficiency(WUE) , and the growth indices, shrub height (H) , shrub diameter (D) , shrub canopy(C). and the gasexchange indices of artificial origins were bigger than that of natural origins, but the growth indices smaller thannatural origins. Among the five species, the difference ofWUE is not remarkable, but the remarkable differencesexist in the gas exchange indices, Pn, Gs, Ci, E, and the growth indices, H, D, C. Some photosynthetic responsecurves parameters, such asmaximum photosynthetic rate, apparent quantum yield, light compensation point, light saturation point, dark resp iration rate, CO₂ compensation point, carboxylation efficiency, were calculated based onthe measured light and CO₂ response curves for five shrubs of two origins. And the diversification of thephotosynthetic response curves parameters for different species and origins exist. And some suggestions for artificialshrub cultivation and natural shrub p rotection measures were put forward.