内蒙古库布齐沙地白刺水势研究

2006年5～9月,采用PSYPRO水势仪,测定了库布齐沙地白刺的叶水势,对叶水势日变化、月变化进行了动态研究,并分析了其影响因子.结果表明:白刺叶水势的日进程在5月、6月、8月份表现双峰曲线变化,7月和9月份则表现单峰曲线规律,12:00左右通常是一天中叶水势的最低值;以6月份叶水势日变化为研究对象,表明水势与气温、光量子通量密度成显著负相关,与大气相对湿度、大气水势、土壤含水量成显著正相关.

Study on the Water Potential of Nitraria tangutorum Bobr.in Kubuqi Desert of Inner Mongolia

The leaf water potential of Nitraria tangutorum Bobr.is measured by PSYPRO water potential guage in Kubuqi desert from May to September in 2006.The daily and seasonal variations of leaf water potential of Nitraria tangutorum Bobr.and related factors are analyzed.The results show that leaf water potentials day-change is double-peak curves in May,June and August,but a single-peak type in July and September.The minimum peak value takes place at 12’ clock and the most essential period for water supply in growing season was July.The leaf water potential has a negative correlation to the air temperature and the photon flux density,and a positive correlation to the humidity.At the same time the leaf water potential shows significantly positive correlation with the three metrological factors including the relative atmospheric humidity,atmospheric water potential,soil water content.