植物生态学报 ›› 2018, Vol. 42 ›› Issue (2): 195-201.doi: 10.17521/cjpe.2017.0082

• 研究论文 • 上一篇    下一篇

基于热比率法的青海云杉林蒸腾量估算

杨军军1,*(),封建民1,何志斌2   

  1. 1咸阳师范学院资源环境与历史文化学院, 陕西咸阳 712000
    2中国科学院西北生态环境资源研究院, 兰州 730000
  • 出版日期:2018-02-20 发布日期:2018-04-16
  • 通讯作者: 杨军军 E-mail:junjun_yang@126.com
  • 基金资助:
    国家科技支撑计划(2014BAL01B03);国家自然科学基金(41522102);陕西省重点科技创新团队计划项目(2016KCT-23)

Estimating whole-tree water use of Picea crassifolia based on heat ratio method

YANG Jun-Jun1,*(),FENG Jian-Min1,HE Zhi-Bin2   

  1. 1College of Resource & Environment and Historical Culture, Xianyang Normal University, Xianyang, Shaanxi 712000, China;

    2Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
  • Online:2018-02-20 Published:2018-04-16
  • Contact: Jun-Jun YANG E-mail:junjun_yang@126.com
  • Supported by:
    Supported by the National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2014BAL01B03);the National Natural Science Foundation of China(41522102);the Shaanxi Province Key Science and Technology Innovation Team Project(2016KCT-23)

摘要:

流域上游森林蒸腾量的准确估算对于干旱区水资源管理至关重要。该文采用热比率法的树干液流技术对青海云杉(Picea crassifolia)单木和林分蒸腾量进行了估算和转换, 目的在于通过该研究为不同尺度森林蒸腾量估算提供一个系统的解决方案。研究结果如下: 第一, 青海云杉胸径与边材面积间存在显著指数函数关系, R2 = 0.94, p < 0.000β1; 第二, 热比率法的青海云杉蒸腾量测量中, 理论值与观测值间的比例系数为1.09, 观测值偏小; 第三, 基于单木平均液流速率和林分总边材面积的林分蒸腾量计算中, 不同胸径样树液流速率的异质会导致液流速率被高估或低估近1/3; 第四, 基于单木胸径与液流量间关系的林分液流估算技术能够更合理地对青海云杉蒸腾量进行估算。根据该文研究结果, 基于探针式液流测量技术可以更为科学地对单一树种研究区不同尺度的蒸腾量进行估算。

关键词: 蒸腾量, 尺度上推, 热比率法, 青海云杉

Abstract:
Aims Accurate estimation of forest transpiration in the upper reach of the watershed is vital to the management of water resources in arid region. The objective of this study was to provide a systematic method for calculating the forest evapotranspiration at different scales. Methods In this study we measured the whole-tree transpiration using the heat ratio method technology and estimated the stand- and catchment-transpiration employing the upscaling methods. Important findings The main results and conclusions were as follows: First, the diameter at breast height (DBH) exhibited significant correlations with sapwood area, and the correlation was characterized by the exponential function (R2=0.94,p<0.001).Second, in the weighted calculation of sap-flux measurements based on two-point thermocouples and sapwood area of Picea crassifolia,the correction coefficient between the true value and the observation value was 1.09. Third, when calculating sap-fluxes based on the average-sap-flux and total sapwood area of stand-transpiration, ignoring sap-flux velocity heterogeneities of trees led to transpiration rates being overestimated or underestimated by nearly one third; Fourth, the stand-transpiration estimation method based on the relationship between DBH and sap-flux can give a more reasonable prediction ofPicea crassifolia transpiration. The results indicated that the probe-based sap-flux measuring technology would perform well for the transpiration scaling-up calculation at the catchment with only one single tree species, and the calculation methodology can be applied to other watersheds.

Key words: transpiration, upscaling, heat ratio method, Picea crassifolia