浅层地下水对华北地区河岸杨树林树干液流的影响  

Influences of shallow groundwater on sap flow of riparian poplar plantations in northern China

作　　者：罗超[1] 查同刚[1] 朱梦洵[1] 朱志俊[1] 王子尧[2] 刘文娜[1] 

机构地区：[1]北京林业大学林业生态工程教育部工程研究中心,北京100083 [2]北京林业大学园林学院,北京100083

出　　处：《应用生态学报》2016年第5期1401-1407,共7页Chinese Journal of Applied Ecology

基　　金：林业公益性行业科研专项项目(201204102);北京林业大学大学生科研训练计划项目(201410022016)资助~~

摘　　要：华北地区河岸杨树林生长季的用水特征对杨树人工林经营管理具有重要意义.本文以北京市潮白河畔的杨树人工林为研究对象,采用热扩散式探针(TDP)测定树干液流、管式TDR土壤含水量法测定土壤体积含水量、开路涡度相关系统测定环境因子数据,对2014年6—7月的杨树树干液流及其影响因素进行系统研究,以探究浅层地下水对树干液流的可能影响.结果表明:杨树树干液流日变化随太阳辐射呈现单峰或双峰变化,在土壤水分相对亏缺时,杨树树干液流密度明显减小,达到峰值的时间从14:00提前到12:30,但树干液流对太阳辐射的时滞效应没有明显变化.在表层土壤水分相对充足时,太阳辐射和空气饱和水汽压差是杨树树干液流变化的主导因子,但在表层土壤水分亏缺时,土壤水会成为杨树树干液流的限制因子;当表层土壤水分相对亏缺时,杨树单株耗水与100 cm土层土壤体积含水量呈显著负相关,与其余各土层体积含水量呈显著正相关.浅层地下水(相对稳定的150 cm及更深处)在土壤表层土壤水分含量相对亏缺时,可在毛管力作用下对上层土壤水进行补充,供给杨树生长需要.Water use strategy in growing seasons plays a great role in the management of riparian poplar plantations in northern China. The research was conducted on a poplar （Populus x euramericana cv. ‘74/76＇ ） plantation located near the floodplain of Chaobai River in the northeastern su- burb of Beijing. The influencing factors of poplar sap flow （SF） were presented based on the measurements on the stem SF with thermal dissipation sap flow probe （TDP）, soil volumetric water content （VWC） with time-domain-reflectometer （TDR） and environmental factors with eddy covafiance system from June to July, 2014, to explore the impact of shallow ground water on SF. The results showed that the diurnal variation of SF presented single or double peaks depending on the varia- tion of solar radiation （R）. The SF density decreased in soil water relative deficient period （ RDP ）, and the peak time advanced to 12：30 from 14：00, while the time lag between the SF density and R showed no obvious change. The solar radiation and air vapor pressure deficit were the predominant factors of SF during soil water relative sufficient period （ RSP ）, while soil water became the limiting factor in RDP. During the RDP, the daily water consumption of individual poplar tree was significantly negatively correlated with soil VWC at the depth of 100 cm, and significantly positively corrlated with soil VWC of the other depths. The shallow ground water （ at the depth of ≥ 150 cm where the soil water content showed little change） might move to the upper soil layer controlled by the capillary force and supply for poplar growth during the soil water-relatively deficient period.

关 键 词：浅层地下水 热扩散法 树干液流 土壤水 河岸杨树林 

分 类 号：S792.11[农业科学—林木遗传育种]