Study on adaptability of physiological ecology of Quercus liaotungensis seedlings under soil drought

Using Quercus liaotungensis as experiment material and pot culture experiments simulating different soil drought, its physiological ecology response under soil drought were studied. The results showed that its consumption water was obvious descended and ahead of peak of consumption water with soil water decreasing. Peak feature of consumption water changed from single to double under severe soil drought. Its leaf potential changed slowly early stress and descended rapidly later. Especially, model of leaf potential was “M” under severe stress. Leaf water content wasn't sensible to soil water content. Water holding ability had slightly increased under media drought. It was a low transpiration tree and average transpiration rate 2.98 μg·cm -2·s -1.Diurnal change of transpiration rate was different in different season. Diurnal change of transpiration rate was double peak curve under normal water and single peak curve under media drought and maintained low level or up and down change under severe drought in August. Transpiration rate decreased 50% in September and had obvious single and double peak. Simple correlation of transpiration rate and environmental factors was analyzed to show that photosynthetic radiation had significant effected on transpiration rate under normal and media drought and air temperature had obvious effected on transpiration rate under severe drought. Transpiration rate ascended under media drought and rapidly descended under severe drought and photosynthesis rate, WUE, carboxylation efficiency decreased with soil water decreasing. Root/Shoot increased and growth of shoot and WUE1 decreased. WUE2 ascended under media drought and descended under severe drought. Its seeding had weak resistance to high temperature and intensive radiation which decreased photosynthesis rate and transpiration rate and physiological activity had significant decreased under severe drought especially.