黄土高原水蚀风蚀交错区不同立地条件下旱柳树干液流差异  

Sapflow Dynamic Changes of Salix matsudana in the Water-Wind Erosion Crisscross Region on the Loess Plateau

作　　者：彭小平[1] 樊军[1,2] 米美霞[1] 薛智德[1] 

机构地区：[1]西北农林科技大学资源环境学院,杨凌712100 [2]中国科学院水利部水土保持研究所,杨凌712100

出　　处：《林业科学》2013年第9期38-45,共8页Scientia Silvae Sinicae

基　　金：国家自然科学基金项目(41271239;51239009;91025018)

摘　　要：应用热扩散式树干茎流计（TDP）对黄土高原水蚀风蚀交错区六道沟小流域内分布在坡地与坝地的旱柳树干液流进行连续监测，探讨2种立地条件下旱柳树干液流量与环境因子关系的差异。结果表明：2种条件下的旱柳树干液流速率变化趋势基本相同，但坝地旱柳的液流速率和树干液流量均显著高于坡地旱柳，坝地旱柳平均液流速率和树干液流量分别是坡地的1．4和3倍。2样地旱柳树干液流量的变化规律与气象因子基本一致，气象因子对旱柳树干液流量影响显著，旱柳树干液流量由气象因子与0～50cm土壤含水量综合作用决定，并且在气象因子增加到某一程度时早柳树干液流量主要受到土壤含水量的影响。2样地土壤质地不同，土壤蒸发和渗漏强度存在较大差异，坡地沙土持水能力差，降雨后水分易发生渗漏，根区土壤有效含水量低，旱柳经常受到干旱胁迫，以致生长不良形成“小老树”；而坝地无渗漏现象发生，供植物吸收的有效水分多，早柳生长良好。A thermal dissipation probe （TDP） was used to measure sap flow of Salix matsudana grown on slope land and dam land in the water-wind erosion crisscross region on the Loess Plateau. The environmental factors, such as soil water content and meteorological parameters, were measured synchronously to investigate the relationship between the sap flow and the environmental factors in the two sites. The results showed that the diurnal variations of S. matsudana sapflow velocity in the two sites were consistent, but the sapflow velocity and sap flow on the dam land were 1.4 times and 3 times higher than those on slope land. The variation pattern of sap flow in the two sites was consistent with the change in meteorological factors. The sap flow was influenced by meteorological factors markedly. The soil moisture of 0 - 50 cm layer was also one of main influence factors. In addition, the sap flow was mainly affected by soil moisture when the meteorological factors increased to a certain extent. The capability of soil evaporation and infiltration was quite different due to the different soil texture in the two sites. On slope land, the water holding capacity ＂was lower, water was easy to leakage after rainfall, thus available moisture of rhizosphere was lower than those on dam land, and the S. matsudana was frequently subjected to drought stress and became ＂small old tree＂. By the contrast, S. matsudana grown on dam land grew well due to sufficient available moisture.

关 键 词：旱柳 树干液流 热扩散式探针 气象因子 土壤水分 黄土高原 

分 类 号：S715[农业科学—林学]