Principal Component Analysis on Drought-resistance of 4 Native Tree Species in Arid Valleys of the Minjiang River

Under natural arid condition,the physiological data of 4 tree species,i.e.,Pinus atbualeformi,Ulmus pumila,Robinia pseudoacac,and Ulmus pumila,which were all 5-year-old,were determined in dry and raining season,respectively.The variation and relationship of the physiological data under drought stress were discussed to perfect the drought theory of plant.Then the method of principal component analysis was used to analyze the physiological data in order to evaluate the ability of drought resistance of the 4 native tree species.The results showed that the drought resistance levels of the 4 native tree species were as follows: Robinia pseudoacacUlmus pumilaUlmus pumilaPinus atbualeformi.