植物生态学报 ›› 2011, Vol. 35 ›› Issue (10): 1029-1037.DOI: 10.3724/SP.J.1258.2011.01029

所属专题: 稳定同位素生态学

• 研究论文 • 上一篇    下一篇

石灰岩地区连片出露石丛生境植物水分来源的季节性差异

聂云鹏1,2,3, 陈洪松1,2,*(), 王克林1,2   

  1. 1中国科学院亚热带农业生态研究所, 亚热带农业生态过程重点实验室, 长沙 410125
    2中国科学院环江喀斯特生态系统观测研究站, 广西环江 547200
    3中国科学院研究生院, 北京 100049
  • 收稿日期:2010-10-29 接受日期:2011-03-11 出版日期:2011-10-29 发布日期:2011-11-07
  • 通讯作者: 陈洪松
  • 作者简介:* (E-mail: hbchs@isa.ac.cn)

Seasonal variation of water sources for plants growing on continuous rock outcrops in limestone area of Southwest China

NIE Yun-Peng1,2,3, CHEN Hong-Song1,2,*(), WANG Ke-Lin1,2   

  1. 1Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China
    2Huanjiang Observation and Research Station for Karst Ecosystems, Chinese Academy of Sciences, Huanjiang, Guangxi 547200, China
    3Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2010-10-29 Accepted:2011-03-11 Online:2011-10-29 Published:2011-11-07
  • Contact: CHEN Hong-Song

摘要:

以桂西北石灰岩地区连片出露石丛生境次生林群落为研究对象, 运用稳定性氢氧同位素技术结合IsoSource模型, 分析了5种典型植物(半落叶乔木粉苹婆(Sterculia euosma)、落叶乔木菜豆树(Radermachera sinica)、常绿灌木鹅掌柴(Schefflera octophylla)以及落叶灌木红背山麻杆(Alchornea trewioides)和紫弹树(Celtis biondii))水分来源的季节性差异。结果表明: 雨季, 除鹅掌柴同时利用部分前期雨水外, 其余4种植物均主要利用最近15天内的雨水(利用比例的平均值之和均超过80%)。旱季, 5种植物均主要利用最近一次雨水与前期雨水(一个月前)的混合(利用比例的平均值之和均超过80%), 其中乔木和常绿灌木对前期雨水的利用比例更高(利用比例的平均值均超过50%)。植被良好的石灰岩连片出露石丛生境中, 植物主要以不同时期的雨水为主要水源, 这可能与石灰岩发育的裂隙及其储水能力有关。储存在裂隙中的雨水通过植物蒸腾的方式返回大气, 这一良好的水文循环过程应得到充分的保护。

关键词: 连片出露石丛, IsoSource模型, 石灰岩, 稳定同位素, 植物水分来源

Abstract:

Aims Woody plants in karst regions often grow on the continuous rock outcrops. However, the source of water for these plants is unclear. This study aimed at investigating the seasonal variation of water sources for plants growing on continuous limestone outcrops in southwestern China.
Methods Stable isotope techniques were used to access plant water uptake patterns for five different species in both wet and dry seasons. Then the IsoSource model was used to determine the probable contribution of each potential water source to total plant water uptake.
Important findings In the wet season, an average of >80% of water for four of the five species came from rainwater received in the previous 15 days and stored in fissures in shallow layers. Water accessed by the other species came mostly from recent rainwater; however, the species simultaneously absorbed water from fissures in deep layers that had been recharged from previous precipitation. In the dry season, all five species utilized both recent and previous rainwater, and the two tree species and one large evergreen shrub species used more previous rainwater (>50%).

Key words: continuous rock outcrops, IsoSource model, limestone, stable isotope, water sources of plants