植物生态学报 ›› 2013, Vol. 37 ›› Issue (12): 1091-1100.DOI: 10.3724/SP.J.1258.2013.00112

所属专题: 稳定同位素生态学 青藏高原植物生态学:生理生态学

• 研究论文 • 上一篇    下一篇

青海湖流域具鳞水柏枝植物水分利用氢同位素示踪研究

赵国琴1,2, 李小雁1,2,*(), 吴华武2, 张思毅2, 李广泳2   

  1. 1地表过程与资源生态国家重点实验室, 北京 100875
    2北京师范大学资源学院, 北京 100875
  • 收稿日期:2013-08-12 接受日期:2013-10-28 出版日期:2013-08-12 发布日期:2013-12-04
  • 通讯作者: 李小雁
  • 作者简介:* E-mail: zhaoguoqin2008@126.com
  • 基金资助:
    国家自然科学基金重点项目(4113-0640);长江学者和创新团队计划“土壤水文与土壤侵蚀”(批准号: IRT1108);中央高校基本科研业务费专项资助

Study on plant water use in Myricaria squamosa with stable hydrogen isotope tracer in Qinghai Lake basin

ZHAO Guo-Qin1,2, LI Xiao-Yan1,2,*(), WU Hua-Wu2, ZHANG Si-Yi2, LI Guang-Yong2   

  1. 1State Key Laboratory of Earth Surface Process and Resource Ecology, Beijing 100875, China
    2College of Resources Sciences and Technology, Beijing Normal University, Beijing 100875, China
  • Received:2013-08-12 Accepted:2013-10-28 Online:2013-08-12 Published:2013-12-04
  • Contact: LI Xiao-Yan

摘要:

具鳞水柏枝(Myricaria squamosa)是我国高寒地区广泛分布的优势河谷灌木, 具有维持河谷湿地系统稳定的功能。然而, 目前国内外有关具鳞水柏枝水分利用来源的定量研究很少。该文运用氢稳定同位素示踪方法, 分析了青海湖流域具鳞水柏枝茎(木质部)水和潜在水源(地下水、河水和土壤水)的氢稳定同位素比率(δD)的季节变化, 发现具鳞水柏枝在不同水文环境下的植物水分利用来源有明显差异。研究结果表明, 生长在河岸边的具鳞水柏枝在6、7月主要利用地下水与河水, 分别占其所利用水分的89%、86%和55%、65%, 8月主要利用0-20 cm土层的土壤水, 9月水源不详。生长在离河岸约100 m处的具鳞水柏枝在6月主要利用地下水与河水(91%、70%), 在7-9月以0-60 cm土层的土壤水为主要水源。这表明生长在河岸边的具鳞水柏枝对地下水和河水的依赖程度较高, 而距离河岸约100 m时对土壤水的利用量较多, 反映出生长在不同生境中的具鳞水柏枝对特定水分条件的特殊适应结果。

关键词: 氘同位素, 具鳞水柏枝, 植物水分, 青海湖流域, 河谷灌木

Abstract:

Aims Little study has been conducted to quantify plant water sources for Myricaria squamosa, which is a dominant alpine riparian shrub in the Qinghai Lake basin and plays a key role in maintaining riverine wetland system. The objective of this study was to quantify water sources for M. squamosa growing under different hydrological conditions.
Methods We collected the water samples from the xylem of M. squamosa, groundwater, river, and soils in the Qinghai Lake basin from June through September, and analyzed the seasonal variation of hydrogen stable isotope ratio (δD) in the xylem and potential water sources using stable hydrogen isotope tracer method. We then compared the differences in water sources for M. squamosa growing under two contrasting hydrological conditions.
Important findings Myricaria squamosa plants growing on the river bank mainly used groundwater and water from the river stream in June and July, with groundwater contributing up to 89% of water use in June and 55% in July and river stream contributing up to 86% in June and 65% in July, respectively; whilst in August, they used water mainly from the 0-20 cm soil layer; the water source in September was identifiable. In contrast, Myricaria squamosa plants growing approximately about 100 m away from the river bank mainly accessed the groundwater and river water in June (91% and 70%, respectively), and used water from the 0-60 cm soil layer during the rainy months July, August and September. Results suggest that M. squamosa plants on the river bank use mainly groundwater and river water; soil water was more important for those far away from the river bank. These are resulted from the responses of this shrub species to specific water conditions when growing under contrasting water regimes.

Key words: deuterium isotope, Myricaria squamosa, plant water use, Qinghai Lake basin, riparian shrub