Study on Drought Resistance of Tree Species on Plateau Hill in Gansu

By calculating water parameters, drawing PV curve and analyzing daily variance of water potential of 4 tree species, including Picea crassifolia, Sabina przewalskii, Populus cathyana, Betula albosinensis on plateau hill in Gansu province, it was found that the 4 tree species have strong drought-resistance and water-keeping ability. The drought-resistance of coniferous is stronger than broad-leaf tree. The bound water content, water-possessing ability, the average of daily water potential and the elasticity of cell of Picea crassifolia is higher than these of Sabina przewalskii, and resisting drought by delaying dehydrate. The relating osmotic water content at loss point ROWC0,the variance of daily water potential and osmotic adjusting ability of Sabina przewalskii is higher than Picea crassifolia, the cell concentration in well swelling, the ability keeping the highest swelling pressure and the comprehensive drought-resistance is higher too, and resisting drought by enduring dehydrate. The bound water content, water-possessing ability of Betula albosinensis is higher, and resisting drought by delaying dehydrate. The average and variance of daily water potential, the ability of adjusting osmotic and keeping the highest swelling pressure of Populus cathyana is higher, and the osmotic potential at loss point is lower, it resists drought by enduring dehydrate mainly.