Influence of Drought Stress on Transpiring Water-consumption of Seedlings
干旱胁迫对苗木蒸腾耗水的影响

Transpiration rates and water consumption of nine main plantation tree species in North China were studied by using Lico 6400 Portable Photosynthesis System and BP3400 Precision Balance etc.. Leaf water potential was measured using pressure chamber in different phase. The water consumption patterns of seedlings were observed in normal water supply and drought stress conditions. The quantity and rate of water consumption were compared and analyzed in different water potentials and in times of day and night. It was showed that water consumption by transpiration mainly occurred in daytime, different seedlings had different water consumptions in the same water status, and with the drought stress increasing, and the water consumption of seedlings decreased with increasing drought stress. When the seedlings were in serious drought stress, water consumption of conifer Pinus tabulaeformis and Platycladus orientalis decreased in 11 7% of that in normal water condition, that of broadleaf arbor decreased in 6 6% and shrubbery decreased in 16 9%. It suggested that the present study focusing on water consumption characteristic and consumption value in different water potentials would be beneficial to afforestation and vegetation reconstruction under condition of water deficiency.