应用生态学报2018，Vol.29Issue(3)：725-731,7.DOI:10.13287/j.1001-9332.201803.019
黄土丘陵区辽东栎树干液流特征对边材面积和土壤水分的响应
Sap flow characteristics of Quercus liaotungensis in response to sapwood area and soil moisture in the loess hilly region,China
摘要
Abstract
To examine the characteristics of sap flow in Quercus liaotungensis and their response to environmental factors under different soil moisture conditions,Granier-type thermal dissipation probes were used to measure xylem sap flow of trees with different sapwood area in a natural Q. liaotungensis forest in the loess hilly region. Solar radiation,air temperature,relative air humidity,precipitation,and soil moisture were monitored during the study period. The results showed that sap flux of Q. liaotungensis reached daily peaks earlier than solar radiation and vapor pressure deficit. The diurnal dynamics of sap flux showed a similar pattern to those of the environmental factors. Trees had larger sap flux during the period with higher soil moisture. Under the same soil moisture conditions,trees with larger diameter and sapwood areas had significantly higher sap flux than those with smaller diameter and sapwood areas. Sap flux could be fitted with vapor pressure deficit,solar radiation,and the integrated index of the two factors using exponential saturation function. Differences in the fitted curves and parameters suggested that sap flux tended to reach saturation faster under higher soil moisture. Furthermore,trees in the smaller diameter class were more sensitive to the changes of soil moisture. The ratio of daily sap flux per unit vapor pressure deficit under lower soil moisture condition to that under higher soil moisture condition was linearly correlated to sapwood area. The regressive slope in smaller diameter class was larger than that in bigger diameter class,which further indicated the higher sensitivity of trees with smaller diameter class to soil moisture. These results indicated that wider sapwood of larger diameter class provided a buffer against drought stress.关键词
黄土丘陵区/辽东栎/液流通量/土壤水分/边材面积Key words
loess hilly region/Quercus liaotungensis/sap flux/soil moisture/sapwood area引用本文复制引用
吕金林,何秋月,闫美杰,李国庆,杜盛..黄土丘陵区辽东栎树干液流特征对边材面积和土壤水分的响应[J].应用生态学报,2018,29(3):725-731,7.基金项目
本文由国家自然科学基金项目(41471440,41171419,41411140035)资助 （41471440,41171419,41411140035）
