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应用生态学报 ›› 2019, Vol. 30 ›› Issue (8): 2607-2613.doi: 10.13287/j.1001-9332.201908.013

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黄土丘陵区辽东栎和刺槐树干液流时滞效应与蒸腾特征的关联性

杨洁1,2, 吕金林2,3, 何秋月1,2, 闫美杰2,3, 李国庆2,3, 杜盛2,3*   

  1. 1西北农林科技大学林学院, 陕西杨凌 712100;
    2西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室, 陕西杨凌 712100;
    3中国科学院水利部水土保持研究所, 陕西杨凌 712100
  • 收稿日期:2019-03-05 出版日期:2019-08-15 发布日期:2019-08-15
  • 通讯作者: * E-mail: shengdu@ms.iswc.ac.cn
  • 作者简介:杨洁,女,1995年生,硕士研究生.主要从事森林蒸腾耗水研究.E-mail:jieyang0216@163.com
  • 基金资助:
    国家重点研发计划项目(2017YFC0504601)和国家自然科学基金项目(41471440)

Time lag of stem sap flow and its relationships with transpiration characteristics in Quercus liaotungensis and Robina pseudoacacia in the loess hilly region, China

YANG Jie1,2, LYU Jin-lin2,3, HE Qiu-yue1,2, YAN Mei-jie2,3, LI Guo-qing2,3, DU Sheng2,3*   

  1. 1College of Forestry, Northwest A&F University, Yangling 712100, Shaanxi, China;
    2State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Northwest A&F University, Yangling 712100, Shaanxi, China;
    3Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, Shaanxi, China.

  • Received:2019-03-05 Online:2019-08-15 Published:2019-08-15
  • Contact: * E-mail: shengdu@ms.iswc.ac.cn

摘要: 运用Granier热扩散探针法,于2016年7—9月对半干旱黄土丘陵区天然次生林树种辽东栎和人工林树种刺槐的树干液流进行连续测定,并同步监测气象因子和土壤含水量,用错位相关法分析液流通量密度与空气水汽压亏缺日变化的时滞长度,研究2个树种不同径级个体在不同土壤水分条件下液流通量密度与蒸腾驱动因子之间的时滞效应.结果表明: 辽东栎和刺槐液流通量密度的日变化节律与气象因子显著相关,空气水汽压亏缺峰值的出现较辽东栎树干液流通量密度滞后118.2 min,较刺槐树干液流通量密度滞后39.5 min;而光合有效辐射的峰值通常滞后于辽东栎12.4 min,提前于刺槐68.5 min.液流通量密度和空气水汽压亏缺的时滞长度与树种和土壤含水量显著相关,辽东栎、刺槐在土壤含水量较高时段的时滞长度分别大于土壤含水量较低时段32.2和68.2 min.时滞长度与径级的相关性整体上未达到显著水平,但在土壤含水量较低时段小径级刺槐的时滞长度大于大径级21.4 min,差异达到了显著水平.两树种液流通量密度与空气水汽压亏缺之间的时滞效应反映了对蒸腾驱动因子的敏感性,较好的土壤水分条件有利于液流通量密度提早达到峰值,较低土壤水分会导致树干液流对气象环境因子响应的敏感性降低;刺槐树干液流受土壤水分的影响更显著.

Abstract: Using Granier-type thermal dissipation probes (TDP), we measured stem xylem sap flow of the natural dominant species Quercus liaotungensis and a reforestation species Robinia pseudoacacia from July to September in 2016 in the semiarid loess hilly region. Meteorological factors and soil water content were simultaneously monitored during the study period. Using cross-correlation analysis, time lag between diurnal patterns of sap flux density and vapor pressure deficit (VPD) was quantitatively estimated. Differences in the time lag between the two species and possible influence by different diameter classes and soil water contents were analyzed. The results showed that the diurnal courses of sap flux density were similar to those of meteorological factors, with daily peaks ear-lier than VPD. The peak of VPD lagged behind the sap flux densities of Q. liaotungensis and R. pseudoacacia 118.2 min and 39.5 min, respectively. The peak of PAR lagged behind the sap flux density of Q. liaotungensis 12.4 min, but was 68.5 min ahead of that for R. pseudoacacia. Time lag between sap flux density and VPD significantly varied between tree species and was affected by soil water content. Those during higher soil water content period were about 32.2 min and 68.2 min longer than those during the period with lower soil water content for the two species, respectively. There was no correlation between time lag and tree diameter classes. The time lag between VPD and sap flux density for R. pseudoacacia was about 21.4 min longer in smaller diameter trees than in larger trees, which was significantly different under the lower soil water content. Our results suggested that the time lag effect between VPD and sap flux densities in the two species reflected their sensitivities to driving factors of transpiration, and that higher soil water content was favorable to sap flux density reaching its peak early. The lower soil water content might lead to lower sensitivity of the trees to meteorological factors. R. pseudoacacia was more sensitive to changes of soil water content.