文献类型：期刊文献

中文题名：毛乌素沙地南缘樟子松树干液流特征及其对环境因子的响应

英文题名：Sap flow variation in Pinus sylvestris var. mongolica plantation at the southern margin of Mu Us sandy land and its response to environmental factors

作者：李明阳[1] 党宏忠[1] 陈帅[2] 刘春颖[1] 杨伟[3] 乔一娜[3]

第一作者：李明阳

机构：[1]中国林业科学研究院生态保护与修复研究所,北京100091;[2]中国农业大学土地科学与技术学院,北京100193;[3]陕西省治沙研究所,陕西榆林毛乌素沙地荒漠生态系统国家定位观测研究站,榆林719000

年份：2023

卷号：37

期号：4

起止页码：153-161

中文期刊名：干旱区资源与环境

外文期刊名：Journal of Arid Land Resources and Environment

收录：北大核心:【北大核心2020】；CSSCI:【CSSCI2023_2024】；CSCD:【CSCD2023_2024】；

基金：国家自然科学基金项目(32071836)资助

语种：中文

中文关键词：边材液流;沙地樟子松;热扩散技术;蒸发需求因子;毛乌素沙地

外文关键词：sap flow;Pinus sylvestris var.mongolica;thermal dissipation probe;evaporative demand index;Mu Us Sandy Land

分类号：Q945

摘要：树木边材液流是实时反映水分利用过程的重要变量。分析液流与环境因子尤其是与土壤水分间的关系,进而明确树木对水分胁迫的响应机制,是认识树木适应环境变化机制的重要内容。文中以毛乌素沙地南缘樟子松人工固沙林为研究对象,采用热扩散式液流计连续监测了树干边材液流速率,分析了液流变化与环境因子间的关系。结果表明:毛乌素沙地樟子松生长季中边材液流速率(J_(s))平均为4.91±1.25cm·h^(-1),最大值为18.75±2.99cm·h^(-1),其中夜间液流速率平均为1.42±0.38cm·h^(-1),最大值为7.47±1.92cm·h^(-1)。J_(s)与环境因子间的主成分分析结果显示,前3个主成分的累积方差贡献率达86.2%,分别解释了方差的54.5%、20.6%、11.1%。其中第一主成分主要包含大气水分亏缺(VPD)、大气温度(T_(a))、太阳辐射(R_(a))等因子,归为蒸发需求因子;第二主成分主要包含风速(W_(s))等因子,为大汽水热散失动力因子;第三主成分主要包含土壤含水率(θ)等因子,为土壤水分供给因子。在第一主成分的因子中,VPD对J_(s)的影响具有明显的阈值效应,当VPD升高到接近于1.43 kPa时,日间液流速率趋于最大值16.15 cm·h^(-1);类似地引起夜间液流阈值效应的VPD值约在0.78 kPa水平。土壤干旱对沙地樟子松日间液流表现出较明显的抑制作用,随着土壤水分亏缺的加剧,夜间液流在全天液流通量中的占比趋于提升,反映出沙地樟子松通过补偿树体水分应对干旱变化的策略与能力。
Sap flow is an important variable to reflect water use of trees in real time in field,so,analysis of the relationship between sap flow and environmental factors,especially soil moisture can clarify the response mechanism of trees in the adaptation to environmental change.In this study,the sap flow velocity of sapwood(J_(s))in Pinus sylvestris var.mongolica plantation at the southern margin of Mu Us Sandy Land was continuously monitored by thermal dissipation sap flow probe,and the relationship between the change of sap flow velocity and the environmental factors was analyzed.The results showed that:Jsvaried with the average of 4.91±1.25cm·h^(-1)and the maximum of 18.75±2.99cm·h^(-1)during the whole growing season in the Mu Us Sandy Land,while the nocturnal sap flow velocity(J_(s-night))in a day varied with the average of 1.42±0.38cm·h^(-1)and the maximum of 7.47±1.92cm·h^(-1).The principal component analysis between Js and environmental factors showed that the cumulative variance contribution rate of the three principal components reached 86.2%,explaining 54.5%,20.6%and 11.1%of the variance,respectively.The first principal component mainly included vapor pressure deficit(VPD),atmospheric temperature(T_(a)),solar radiation(R_(a)),which can be classified as the evaporation demand index;The second principal component mainly included wind speed(W_(s)),classified as the hydrothermal dissipation index;The third principal component mainly included soil volume water content(θ),which as the soil water supply index.VPD,as one of the factor in first principal components for influencing on Js,had obvious threshold effect,when VPD increased to 1.43 kPa,the daytime sap flow velocity increased to the maximum of 16.15cm·h^(-1).Similarly,the VPD value that caused the threshold effect of the nocturnal sap flow was about 0.78 kPa.Soil drought had a significantly inhibited effect on the daytime sap flow in Pinus sylvestris var.mongolica on sandy land.The proportion of nocturnal sap flow to the whole day sap flux tended to increase with the aggravation of drought,which reflects the strategy and ability of Pinus sylvestris var.mongolica on sandy land to cope with soil drought by compensating tree water.