植物生态学报 ›› 2023, Vol. 47 ›› Issue (2): 227-237.DOI: 10.17521/cjpe.2022.0100

• 研究论文 • 上一篇    下一篇

黄土丘陵区辽东栎和刺槐树干径向生长与微变化季节动态特征

刘美君1,2, 陈秋文1,2, 吕金林3,4, 李国庆1,3, 杜盛1,3,*()   

  1. 1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
    2西北农林科技大学林学院, 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
    4陕西省西安植物园, 西安 710061
  • 收稿日期:2022-03-18 接受日期:2022-07-06 出版日期:2023-02-20 发布日期:2023-02-28
  • 通讯作者: ORCID: *杜盛: 0000-0002-5580-399X(shengdu@ms.iswc.ac.cn)
  • 基金资助:
    国家重点研发计划(2017YFC0504601)

Seasonal dynamics of radial growth and micro-variation in stems of Quercus mongolica var. liaotungensis and Robinia pseudoacacia in loess hilly region

LIU Mei-Jun1,2, CHEN Qiu-Wen1,2, LÜ Jin-Lin3,4, LI Guo-Qing1,3, DU Sheng1,3,*()   

  1. 1State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, China
    2College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China
    3Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi 712100, China
    4Xi’an Botanical Garden of Shaanxi Province, Xi’an 710061, China
  • Received:2022-03-18 Accepted:2022-07-06 Online:2023-02-20 Published:2023-02-28
  • Contact: *(shengdu@ms.iswc.ac.cn)
  • Supported by:
    National Key R&D Program of China(2017YFC0504601)

摘要:

树干径向生长和微变化动态受树种特性和环境因子的综合影响, 是树木响应环境因子的重要表征。解析树干直径在不同时间尺度上的动态特征是探明树木水分生理生态特性的重要途径, 在水分胁迫风险较高的半干旱地区更具有特殊意义。该研究以半干旱黄土丘陵区两典型造林树种辽东栎(Quercus mongolica var. liaotungensis)和刺槐(Robinia pseudoacacia)为对象, 运用DC3型高精度树干径向变化记录仪监测树干直径变化动态, 同步测定土壤水分动态和驱动蒸腾作用的主要气象因子, 分析两树种树干径向生长特征、直径微变化日动态与季节动态及其对环境因子的响应。结果表明, 两树种树干直径的季节性变化可划分为非生长季收缩阶段、过渡阶段和生长季增长阶段。辽东栎和刺槐径向生长启动时间分别为4月7日和5月4日前后, 9月下旬基本停止生长; 在生长阶段直径变化可分别利用指数饱和增长函数和线性增长函数拟合。两树种直径日变化模式在11月至次年3月为典型的非生长季模式, 6-9月为典型的生长季模式, 而在4-5月两树种的直径日变化模式不同, 反映了两树种的生长节律和物候期差异。非生长季两树种直径日最大收缩量均与气温、空气水汽压亏缺呈显著负相关关系, 而在生长季呈显著正相关关系。非生长季直径的收缩和膨胀受气温的影响较大, 生长季直径的日变化主要受蒸腾导致的树体内水分动态变化的影响。采用直径逐日变化量表征树体蒸腾失水量, 在自然差异的两个土壤水分条件下辽东栎单位空气水汽压亏缺的蒸腾失水量差异显著, 表明蒸腾耗水对驱动因子的响应程度发生调整, 而刺槐未达到显著水平。研究结果对于深入揭示两树种直径微变化机理以及在土壤水分变化时叶部蒸腾的调节策略具有重要贡献。

关键词: 辽东栎, 刺槐, 径向生长, 树干直径微变化, 日变化, 季节动态

Abstract:

Aims The dynamics of radial growth and micro-variation in tree stems are jointly controlled by species-specific properties and environmental factors, and reflect the characteristics of trees in response to change of environments. Exploring the dynamic characteristics of diameter changes in various temporal scales and their relationships with environmental factors is an important way for revealing the species ecophysiological properties, particularly in semiarid areas where the trees are subjected to high risk of water stress. Our objectives were to clarify the year-round radial growth patterns and dynamics of micro-variations in stems of two semiarid afforestation species, Quercus mongolicavar. liaotungensis and Robinia pseudoacacia,and their response to major environmental factors.

Methods We used DC3 dendrometers to monitor stem diameters in order to investigate year-round dynamics of radial growth and stem micro-variations of the two species, Q. mongolicavar. liaotungensis and R. pseudoacacia, in the loess hilly region. Soil moisture dynamics and the main meteorological factors driving transpiration were simultaneously monitored for analyses on the relationship between stem micro-variation and environmental factors.

Important findings The year-round change of stem diameter in the two species could be divided into a contraction phase during the non-growing season, a transition phase and a growing phase during the growing season. The radial growth of Q. mongolicavar. liaotungensis and R. pseudoacacia started around April 7 and May 4, respectively, and ceased in late September. The diameter changes for the growing phase in Q. mongolicavar. liaotungensis and R. pseudoacacia could be fitted by the exponential saturation growth function and the linear growth function, respectively. The diurnal courses of stem micro-variation for both species were grouped monthly, which showed a typical non-growing (November to March of next year) and a typical growing season (June to September) patterns, while it differed between the two species in April and May, probably due to their species-specific phenological rhythm. The daily maximum diameter shrinkage for both tree species was negatively correlated with air temperature and air vapor pressure deficit during the non-growing season, but positively with those during the growing season. The diameter shrinkage and expansion during non-growing season were strongly influenced by air temperature, while those during the growing season were mainly caused by changes in water within the stem due to transpiration and replenishment. The daily variation of diameter could be used to characterize the water loss through transpiration. The water loss per unit of air vapor pressure deficit in Q. mongolicavar. liaotungensis showed significant difference under two periods differing in soil moisture condition, whereas that in R. pseudoacacia did not reach a significant level, indicating that Q. mongolicavar. liaotungensis adjusted its response level of transpiration to the driving factor. Those results may contribute to clarifying the mechanism of stem micro-variation in the two species and the species-specific strategies for regulation of leaf transpiration in response to changes in soil water condition.

Key words: Quercus mongolicavar. liaotungensis, Robinia pseudoacacia, radial growth, stem diameter micro-variation, diurnal variation, seasonal dynamic