内蒙古库布齐沙漠四翅滨藜叶水势研究

2006年5-9月.采用PSYPRO露点水势仪和稳态气孔计Li-1600,在库布齐沙漠测定了从美国引种的四翅滨藜的叶水势和蒸腾速率的日、月动态变化,并与同期测定的杨柴、白刺的叶水势进行了比较,旨在为这一优良灌木树种的推广及管理提供理论依据.结果表明:四翅滨藜叶水势在月和9月的较高,生长最旺盛的6-8月较低;一天中,叶水势与气温和太阳辐射强度呈负相关,与大气相对湿度成显著正相关.气温与大气相对湿度的综合作用对叶水势影响显著:在低温高湿时,叶水势最高;在低温低湿和高温高湿时,叶水势均较低;在高温低湿时,叶水势维持在相对较高的水平.在相同条件下,四翅滨藜的叶水势较杨柴和白刺的要低,表明它从干旱土壤中吸收水分的能力比另外两者更强.

Study on the Leaf Water Potential of Atriplex canescens in Kubuqi Desert of Inner Mongolia

The leaf water potential and transpiration rate of Atriplex canescens was measured by PSYPRO water potential apparatus and steady state porometer Li-1600 respectively in Kubuqi desert from May to September in 2006.The daily and seasonal variations of leaf water potential of Atriplex canescens and related factors were analyzed;also the paper compared it with that of Hedysanm mongolicum and Nitraria tangutorum measured at the same time.The results showed:leaf water potential is higher in May and September than that of in June,July and August.The leaf water potential had a negative correlation to air temperature and solar radiation,and a positive correlation to relative humidity.The study also showed that lower temperature with higher humidity lead to the highest leaf water potential,lower temperature with lower humidity or higher temperature with higher humidity lead to the lowest leaf water potential,higher temperature with lower humidity lead to a relative higher leaf water potential.In the same condition,the water potential of Atriple.r canescens is lower than that of Hedysanm mongolicum and Nitraria tangutorura,which means the ability for absorbing water from dry soil of Atriplex canescens is better than other two species.