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中国沙漠 ›› 2016, Vol. 36 ›› Issue (1): 199-205.DOI: 10.7522/j.issn.1000-694X.2015.00135

• 生物与土壤 • 上一篇    下一篇

不同林龄柠条(Caragana korshinskii)的光合特性和水分利用特征

鲍婧婷1,2, 王进2, 苏洁琼2   

  1. 1. 兰州理工大学 生命科学与工程学院, 甘肃 兰州 730050;
    2. 中国科学院寒区旱区环境与工程研究所 沙坡头沙漠研究试验站/甘肃省寒区旱区逆境生理与生态重点实验室, 甘肃 兰州 730000
  • 收稿日期:2015-07-14 修回日期:2015-08-30 出版日期:2016-01-20 发布日期:2016-01-20
  • 作者简介:鲍婧婷(1980-),女,甘肃兰州人,博士研究生,讲师,主要从事干旱区生态学研究。E-mail:jingtingbao@126.com
  • 基金资助:
    国家重点基础研究发展计划项目(2013CB429906);国家自然科学基金项目(41201250,41401334);兰州市科技计划项目(2011-1-35);中国科学院寒区旱区环境与工程研究所青-人才基金项目(Y451121001)

Photosynthetic Properties and Water Use Characteristics in Caragana korshinskii in Different Ages

Bao Jingting1,2, Wang Jin2, Su Jieqiong2   

  1. 1. School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China;
    2. Shapotou Desert Experiment and Research Station/Key Labortory of Sterss Physiology and Ecology in Cold and Arid Regions of Gansu Province, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
  • Received:2015-07-14 Revised:2015-08-30 Online:2016-01-20 Published:2016-01-20

摘要: 柠条(Caragana korshinskii)是宁夏沙坡头地区的主要固沙灌木,建植初期表现出较强适应性,但随着年龄增长和土壤水分耗竭,开始出现衰退。为探明灌木年龄与其退化的关系,野外原位测定了不同林龄(3、13、25龄)柠条的叶水势、叶相对含水量、叶表观导水率、净光合速率及水分利用效率,分析了其光合特性与叶水势的关系。结果表明:(1)不同林龄柠条的光合能力和水分利用效率差异显著,中龄、幼龄的光合能力高于老龄,而水分利用效率低于老龄;(2)净光合速率、气孔导度与叶水势的非线性关系,反映出不同林龄柠条采取不同策略应对干旱胁迫,幼龄柠条通过快速关闭气孔来减少水分散失,而中龄和老龄柠条通过调整水分利用策略来应对干旱。老龄柠条通过提高水分利用效率来使水分利用最大化,但其植物水势和光合的降低可能导致生长减缓和衰退。

关键词: 柠条(Caragana korshinskii), 林龄, 光合速率, 水分利用效率

Abstract: Caragana korshinskii is widely used for sand-binding in Shapotou, Ningxia, China. Ii has adapted well to the habitat during the establishment. With the increasing age and the consumption of available soil water, the initially-planted C. korshinskii had degraded. To examine the relationship between the shrub age and the population degradation, we conducted field experiments on different-aged C. korshinskii (25-, 13- and 3-year-old) for the measurements of leaf water potential, leaf relative water content, leaf-specific apparent hydraulic conductance, photosynthetic rate and water use efficiency. We analyzed the relationships between photosynthetic properties and leaf water potential among the different-aged shrubs. The results showed that the photosynthetic capacities of young-mature and juvenile were higher than those of old-growth, while their water use efficiencies were lower compared to old-growth. The nonlinear relationships between both net assimilation rate (A) and stomatal conductance (Gs) with leaf water potential (Ψ) show that different-aged C. korshinskii plants adopt different drought response strategies. Juveniles reduce water loss through closing stomata, while older C. korshinskii plants respond to drought by adjusting WUE. Although the old-growth C. korshinskii maximized water use by increasing the WUE, the decreased photosynthesis and plant water potentials would slow the growth of plants and lead to their degradation.

Key words: Caragana korshinskii, shrub age, photosynthetic rate, water use efficiency

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