文献类型：期刊文献

中文题名：沙地赤松树干边材液流速率的方位特征研究

英文题名：Azimuthal Variation of the Sap Flow Rate in the Trunk of Pinus densiflora Planted in Sandy Land

作者：韩辉[1,2] 张学利[1,2] 党宏忠[3] 宋晓东[1,2] 孟鹏[1,2] 张日升[1,2]

第一作者：韩辉

机构：[1]辽宁省固沙造林研究所;[2]辽宁章古台科尔沁沙地生态系统国家定位观测研究站;[3]中国林业科学研究院荒漠化研究所

年份：2019

卷号：32

期号：2

起止页码：39-45

中文期刊名：林业科学研究

外文期刊名：Forest Research

收录：CSTPCD;;Scopus;北大核心:【北大核心2017】；CSCD:【CSCD2019_2020】；

基金：国家自然科学基金(31570704);中央基本科研业务资金(CAFYBB2014MA013)

语种：中文

中文关键词：液流速率;赤松;方位;水分利用;热扩散技术(TDP)

外文关键词：sap flow rate;Pinus densiflora;azimuth;water use;Thermal Dissipation;Probe method (TDP)

分类号：S718.45

摘要：[目的]确定优良固沙树种沙地赤松(Pinus densiflora)树干边材液流速率(J_s)方位变化规律,探讨环境因素对方位差异的影响。[方法]采用热扩散式树干液流计(TDP)连续监测树干液流并同步监测环境因素,比较分析不同方位树干液流速率的差异、季节动态及与降水、土壤体积含水率(θ)、太阳辐射强度(R_s)间的关系。[结果]表明:(1)在赤松树干东、南、西、北4个方位上,J_s的日变化与季节变化均呈现出基本一致的格局,且均与R_s间表现出紧密的协同变化关系;(2)在中等强度干旱和极端干旱情况下,各方位边材J_s均同步受到明显抑制,在土壤水分得到充分补充后又快速回升;(3)在典型晴日里,树干各方位边材J_s其午间峰值出现的时刻有差异,呈从早到晚分别是东侧、南侧、西侧、北侧这种顺时针的方位规律;(4)在整个生长季,J_s的日平均值大小一般为南侧>西侧>北侧>东侧,但方位间差异并不显著(P=0.35),北侧J_s的平均值最接近4个方位的平均值(约为平均值的1.01倍)。[结论]为降低观测成本,通过北侧一个方位的测定来估算赤松单株的液流通量具有较好的可靠性;影响赤松各方位液流过程明显变化的θ的阈值为7.5%。
[Objective] To determine the azimuthal variation of the sap flow rate of trunks (Js) and estimate the effects of environmental factors on azimuthal variation.[Method] The sap flow rate of Pinus densiflora, an important windbreak and sand fixation species, was monitored continuously during the growing season using a thermal dissipation probe (TDP) method, combined with simultaneous observations of precipitation, soil moisture, and solar radiation and other environmental factors.[Result] The results of comprehensive analysis showed that the daily and seasonal changes of the Js in the four directions of the trunk basically followed the same pattern, and all were in accordance with the solar radiation. In moderate-intensity drought and extreme drought conditions, the Js of each direction was significantly suppressed simultaneously and quickly recovered after the soil moisture was fully replenished. On a typical sunny day, there were differences in the time at which the peaks of the Js appeared at various times. From early to later, it ranked with the order of the east, south, west, and north sides clockwisely. During the whole growing season, the daily mean value of Js was generally ranked of south > west > north > east, but the difference between directions was not significant (P=0.35). Statistics show that the average of the Js in the north side was the closest to the average of four azimuths (approximately 1.01 times the average).[Conclusion] The sap flow estimated through a measurement on the north side in the actual measurement will get better reliability in order to reduce the cost of observation. Meanwhile, the threshold value of soil moisture affecting the sap flow of Pinus densiflora is about 7.5%.