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.