Abstract: Water physiological was on four dominant species in different successional communities on Mountain Xiangshan,Huaibai,China,The results showed that the two widely distributed dominant species(Zizyphus jujuba var. spinosa,Vitex negundo var. cannabifolia) show more drought resistance than the two locally distributed dominant species(Cudrania tricuspidata,Broussonetia papyrifera) in the same community(the mixed forest),while the latter have greater capabilities of resource harvesting and growing than the former. Z.jujuba var. spinosa and V.negundo var. cannabifolia are different in drought enduring mechanism,and the former belong to lower water potential drought enduring plant,while the latter belong to higher water potential drought enduring plant.Both of Z.jujuba var. spinosa and V.negundo var. cannabifolia show great physiological plasticity in response to different community environment,their drought resistance in different community is ordered as: the inner mixed forest>the edge of mixed forest>shrub>shrub-herb>Platycladus orientalis forest.The strong drought tolerance and wide ecological amplitude due to great physiological plasticity may be the important reason why Z.jujuba var. spinosa and V.negundo var. cannabifolia be the two widely distributed dominant species on Mountain Xiangshan.

Key words: resume succession, dominant species, water physiology, drought resistance, phenotypic plasticity