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应用生态学报 ›› 2018, Vol. 29 ›› Issue (5): 1503-1514.doi: 10.13287/j.1001-9332.201805.006

• 研究论文 • 上一篇    下一篇

六盘山南侧华北落叶松人工林冠层蒸腾及其影响因子的坡位差异

王云霓1,2,3, 曹恭祥1,2, 王彦辉2, 徐丽宏2, 张文军1, 王晓江1,3*   

  1. 1内蒙古自治区林业科学研究院, 呼和浩特 010010;
    2中国林业科学研究院森林生态环境与保护研究所, 北京 100091;
    3内蒙古大青山森林生态系统国家定位观测研究站, 内蒙古武川 011700
  • 收稿日期:2017-09-07 出版日期:2018-05-18 发布日期:2018-05-18
  • 通讯作者: *E-mail: xjwang_21cn@163.com
  • 作者简介:王云霓, 女, 1987年生, 博士, 助理研究员. 主要从事生态水文及森林经营研究. E-mail: yunni5186@126.com
  • 基金资助:
    本文由国家自然科学基金项目(41471029)和内蒙古自治区自然科学基金项目(2017BS0312)资助

Canopy transpiration of Larix principis-rupprechtii plantation and its impact factors in diffe-rent slope locations at the south side of Liupan Mountains, China.

WANG Yun-ni1,2,3, CAO Gong-xiang1,2, WANG Yan-hui2, XU Li-hong2, ZHANG Wen-jun1, WANG Xiao-jiang1,3*   

  1. 1Inner Mongolia Academy of Forestry, Hohhot 010010, China;
    2Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China;
    3Inner Mongolia Daqingshan Forest Ecosystem Research Station, Wuchuan 011700, Inner Mongolia, China
  • Received:2017-09-07 Online:2018-05-18 Published:2018-05-18
  • Contact: *E-mail: xjwang_21cn@163.com
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (41471029) and the Natural Science Foundation of Inner Mongolia (2017BS0312)

摘要: 2014年5—10月,在宁夏六盘山香水河小流域选择了一个东南坡向的典型华北落叶松人工林坡面,设立上、中上、中、中下、下5个坡位的样地(P1、P2、P3、P4、P5),利用热扩散探针法监测树干液流,并同步监测气象、土壤水势等环境因子.结果表明: 研究期间林分日蒸腾(Tr,mm·d-1)存在显著的坡位差异,不同坡位Tr为:P2(0.975)>P4(0.876)>P3(0.726)>P1(0.653)>P5(0.628).Tr与日最高气温(Tmax)、日均太阳辐射强度(SR)、日均饱和水汽压差(VPD)、日潜在蒸散(PET)、日均土壤水势(Ψ)呈显著正相关,与日均大气相对湿度(RH)、日降水量(P)、日最低气温(Tmin)呈显著负相关.基于边界线的斜率绝对值分析表明,从坡上到坡下,Tr对日均气温(T)、RH、VPD、PET和Ψ的响应呈现逐渐减小的趋势,而对SR、土壤体积含水量(VSM)的响应程度则逐渐增大.进一步回归分析和偏相关分析表明,VPD、PET和RH对不同坡位Tr的影响均占主导地位,ΨT对上坡样地Tr影响较大,而下坡样地Tr受SR、Tmin和VSM的影响较大.总体来看,Tr的坡位差异是土壤水分和气象条件共同作用的结果,在利用特定观测样地的液流速率尺度外推计算坡面Tr时,需同时考虑土壤水分和气象因子随坡位的变化.

Abstract: Based on a continuous field observation in the Larix principis-rupprechtii plantation plots, located at the upper (P1), middle-upper (P2), middle (P3), middle-lower (P4), and lower (P5) positions, in a southeast-facing slope of the Xiangshuihe watershed of Liupan Mountains, China, the stem sap flow was observed with the thermal diffusivity probe method. The soil water potential and meteorological factors were monitored from May to October, 2014. We found significant differences among slope positions in the daily forest transpiration (Tr, mm·d-1), with an order of P2 (0.975)>P4 (0.876)>P3 (0.726)>P1 (0.653)>P5 (0.628). Tr was significantly positively correlated with the daily maximum temperature (Tmax), daily mean solar radiation (SR), daily mean saturated vapor pressure deficit (VPD), potential evapotranspiration (PET), and daily mean soil water potential (Ψ), but negatively correlated with the daily mean air relative humidity (RH), daily precipitation (P), and daily minimum temperature (Tmin). According to the upper boundary line ana-lysis, significant differences were found in the degree of Tr responding to each single environmental factor among slope positions. The degree of its responses gradually decreased for average daily air temperature (T), RH, VPD, PET and Ψ, whereas increased for the SR and daily average volumetric soil water content (VSM) from the upper position to the lower. Results from regression and partial correlation analysis showed that variation of Tr was mainly controlled by VPD, PET and RH in different slope positions. Tr was also strongly affected by Ψ and T in the upper-slope positions and by SR, Tmin and VSM at the lower-slope positions. Generally, the Tr difference among slope positions was a consequence of joint contributions of soil water and meteorological factors. It is necessary to consider the changes of soil water and meteorological factors in different positions along the slope when examining slope-scale or watershed-scale forest transpiration with sap flow estimated from xylem sap flux density measurements of a particular plot.