库布齐沙地杨柴叶水势的研究

Leaf Water Potential of Hedysanm mongolicum in Kubuqi Desert of Inner Mongolia

采用PSYPRO水势仪,测定了库布齐沙地4年生杨柴林林木的叶水势状况,据此,对杨柴叶水势的日变化、月变化进行了动态研究,并分析了其的影响因子。结果表明:杨柴叶水势的日进程在5月、6月、9月表现为单峰曲线变化,7月和8月则呈现双峰曲线规律,12∶00时左右通常是一天中杨柴叶水势最低值的出现时间,7月是杨柴生长需水的最关键时期;杨柴叶水势的日变化与气温、光量子通量密度成显著负相关,与大气相对湿度成显著正相关,且与三者的综合因子相关性显著;盆栽杨柴苗株的清晨叶水势与其土壤含水量的关系密切。研究所获的相关性均拟合出相应的相关方程。

The leaf water potential of Hedysanm mongolicum in Kubuqi desert was measured by PSYPRO water potential guage. The daily and seasonal variations of leaf water potential and related factors were analyzed. The results were as follows： 1 ） Leaf water potential＇s day-change was single-peak curve in May, June and September, showed double-peak curve in July and August. 2） The minimum peak value took place around 12：00 and the most essen-tial period for water supply in growing season was July. 3 ） The leaf water potential had 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 showed high correlation with the three metrological factors. 4） The study also showed it had a remarkable correlation between the pre-down leaf water potential with soil water content of three-year-old spotted H. mongolicum.