Desertification is the most serious ecological/environmental problem in dry land. The most effective way for desertification combating and ecological restoration is the vegetation rehabilitation. However, we have less knowledge on germination and growth of key species grown in desertificated area. Agropyron cristatum and Caragana microphylla are such important key species in Horqin Sandy land, Inner Mongolia, China. In this study, we investigated germination and growth responses to water stress and other environmental factors of these two species.

The germination percentages of A. cristatum and C. microphylla were depressed by both low and high water stress treatments under any temperatures (10-30°C), while it was promoted by lower temperature in A. cristatum, but by higher temperature in C. microphylla. The leaf area, dry weight of whole plant and shoot/root (S/R) ratio decreased as water stress increased in A. cristatum. In C. microphylla, however, leaf area and S/R ratio were almost constant in all water stress treatments, while dry weight of whole plant decreased as water stress increased.

From these results, we consider the effective way how to use these plants for desertification rehabilitation. We also discuss germination/growth responses of Mongolian eco-types compared with Chinese ones.