宁夏中部干旱带人工柠条茎流及蒸腾特征研究

The Study on Sap Flow and Transpiration of Artificial Caragana korshinkii in the Arid Area of Central Ningxia Hui Autonomous Region

采用包裹式茎流测定系统,2010年7月在宁夏盐池对人工栽植的柠条液流蒸腾和环境因子进行了昼夜连续观测,建立了柠条蒸腾的回归模型。结果表明:白天枝条液流速率与枝条的粗细呈正相关,枝条间的液流速率差异在白天大,夜间小;在晴天观测到的蒸腾耗水率日变化曲线出现午间降低现象。柠条在夜间存在液流和微弱蒸腾作用。柠条蒸腾耗水率与太阳辐射、气温、空气饱和差和空气相对湿度具有显著的相关性,得到了蒸腾耗水率与环境因子的的回归方程。

In July of 2010,daily sap flow of Caragana korshinskii was measured by Dynagage Systems,and the microclimate was monitored by Vantage Pro 2 Station in the stand of Caragana korshinskii plantation located in Yanchi County of Ningxia Hui Autonomous Region.The regressive models of transpiration estimated from sap flow were established based on the field observation data.The results showed that there was more sap flow flux founded in bigger diameter branch than that of in smaller one.The difference of sap flow flux between branches is much more significant in the daytime than that of in the night.It was found that there was a noon break phenomenon in the daily course of transpiration in the sunny day.Night-time sap flow and weak transpiration had been detected by Dynagage Systems.Transpiration of Caragana korshinskii was well correlated with solar radiation,air temperature,vapor pressure deficit（VPD）,relative humidity.The regressive equations between the transpiration and environmental factors were better fitted with observed data.