A Study of Drought Resistance of Four Shrub Species in Arid Valleys of the Minjiang River

The arid valley in the Minjiang River was one of the worst ecotopes in China.In the last 20th century human disturbances made the ecological enviroment worse apace.In order to offer grounds for the restration of vegetation,researches were conducted on Sophora davidiana、Bauhinia faberi var.microphylla、Convolvulus tragacanthoides、Artemisia gmelinii growing in the arid valleys of the Zagunao River.The results showed that 4 shrub species had not only significant differences in drought resistance indexes,but also difference in the same drought resistance indexs of the same species in different growth periods.It was very difficult to evaluate accurately tree species's drought resistance by single index,so the principle component method was used to make an integrated estimate.The result showed that the 4 shrub species' ability of drought resistance was as follows:Sophora davidianaBauhinia faberi var.microphyllaConvolvulus tragacanthoidesArtemisia gmelinii.This result could provide a basis for improving plantation' ability of drought resistance and choosing the best tree species.