罗布麻茎直径和茎流变化日过程及其与环境因子的关系分析

采用以色列PhyTech公司生产的Phytalk植物生理生态监控系统,对生长在塔里木河下游极端干旱环境条件下的半灌木植物罗布麻(Apocynum venetum L.)的茎直径、茎流变化日过程及其环境因子进行了同步监测,并对它们之间的关系进行了分析.结果表明:生长在极端干旱区的罗布麻茎直径变化日过程呈现出明显的昼夜变化规律,白天收缩,傍晚、夜间复原或膨胀,径差连日变化呈增长趋势,说明罗布麻能够在极端干旱的环境中正常生长;罗布麻茎直径变化主要受太阳总辐射、土壤湿度和风速的影响;罗布麻茎流日变化呈单峰型曲线,且夜间仍保持一定流速,茎流变化受饱和水汽压差、太阳总辐射、土壤湿度和空气温度的影响.

Analysis on Correlation between Day Process of Stem Diameter and Sap Flow Variations of Apocynum venetum L. and Their Environmental Factors

The day process of the stem diameter variations and sap flow of Apocynum venetum growing in the lower reaches of Tarim River,and the environmental factors are monitored simultaneously using a Phytalk phytomonitor system which is produced by PhyTech Company in Israel,and the correlations between them are analyzed.The results are as follows:The day process of the stem diameter variations of Apocynum venetum has obvious day and night variation law,which shows that it is shrinking in the day and swelling in the night.The difference of increasing trend of stem diameter indicates that Apocynum venetum can grow in the arid environment.The stem diameter variations are mainly affected by factors of solar radiation,soil moisture and wind speed.The diurnal variation of sap flow rate of Apocynum venetum appears single-apex curve.There is still sap flow in night.The vapor pressure deficit,solar radiation,soil moisture and air temperature play critical role in affecting sap flow.