论文部分内容阅读
研究毛乌素沙地旱柳(Salix matsudana)和小叶杨(Populus simonii)树干液流密度的变化特征及其与气象因子的关系,是实现该地区水与生态和谐发展的基础。利用Granier热消散探针法测量了旱柳和小叶杨不同方向和不同深度的树干液流密度。监测结果表明:不同方位间的树干液流密度日变化特征相似并具有较强的相关性,但监测结果相差较大;不同深度的监测结果也具有类似的特征。如果忽略这种方位间和深度上的变化,整树耗水计算结果的误差最大可达104%。树干液流密度与气象因子的相关分析表明,旱柳和小叶杨的树干液流密度与大气辐射相关性最好,其次为气温。时滞分析表明,旱柳和小叶杨的树干液流密度与净辐射没有时滞,与水汽压亏缺间存在1 h的滞后。由此可见,以树干径流结果为基础在推算单株耗水量时,必须考虑方位及探头深度并合理校正。
Studying the characteristics of sap flow density and its relationship with meteorological factors in Salix matsudana and Populus simonii in Mu Us sandy land is the basis for the harmonious development of water and ecology in the area. The sap flow density of Salix psammophila and Populus simonii in different directions and depths was measured by the Granier heat dissipation probe method. The monitoring results show that the diurnal variations of tree trunk flow density in different directions are similar and have strong correlation, but the monitoring results are quite different. The monitoring results at different depths also have similar characteristics. If you ignore this variation between the azimuth and depth, the error of the calculation results of the whole tree water consumption up to 104%. Correlation analysis of trunk flow density and meteorological factors showed that the correlation between the trunk flow density and the atmospheric radiation was the best, followed by the temperature. The time-lag analysis shows that there is no time lag between the trunk flow density and the net radiation of the Salix psammophila and Populus simonii, and there is a lag of 1 h between the vapor pressure deficit. Thus, based on the trunk runoff results in the calculation of plant water consumption, we must consider the azimuth and probe depth and reasonable correction.