中文摘要：

为研究沙柳蒸腾规律及其与气象要素的关系, 采用包裹式茎流计测量沙柳全叶期至落叶期液流速率, 并分析了沙柳蒸腾与气象要素的关系.研究结果表明： 沙柳枝条液流速率与其直径呈正相关关系; 沙柳液流在早7 时开始, 10 时至15 时处于高值, 16 时后急剧减少, 至夜间21 时后降至最低（ 接近0） ; 沙柳液流速率具有典型的季节性特征, 且受气象要素影响显著, 其受影响强烈程度的大小顺序为： 饱和水汽压差〉 太阳辐射〉 大气温度〉 相对湿度〉风速; 另外, 参考蒸散发量和液流速率呈显著线性关系, 随着潜在蒸散发的增加, 沙柳蒸腾也呈增加趋势.

英文摘要：

In order t o investigate the relationship between the transpiration of Salix psammophila and meteorological factors, packaged sap flow gauge w as used to measure the sap flow velocities in the full leaf season and defoliation season. The results show ed that ( 1) the sap flow velocity of Salix psammophila branch has a positive correlation w ith branch diameter; ( 2) sap flow velocity increases gradually from 7 am in the morning, reaches a peak between 10 am in the morning and 3 pm in the aft ernoon, then decreases gradually from 4 pm in the aft ernoon to the low est value ( near zero) aft er 9 pm at night; ( 3) sap flow velocity of Salix psammophila has an obviously seasonal variat ion w ith the maximum value in July while the minimum in November; ( 4) met eorological factors are the most significant factors affecting the sap flow velocity of Salix psammophila in the following or-der: vapor pressure deficit> solar radiation> air tem perat ure> relative humidity> w ind speed; and ( 5) there is a significant ly linear relat ionship betw een sap f low velocity and reference evapotranspiration w ith a correlat ion coefficient of R2 = 0. 77.