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干旱区地理 ›› 2021, Vol. 44 ›› Issue (3): 612-619.doi: 10.12118/j.issn.1000–6060.2021.03.02

• 塔里木河流域生态与环境 • 上一篇    下一篇

塔里木河下游胡杨水分传输过程研究综述

陈亚鹏(),周洪华,朱成刚   

  1. 中国科学院新疆生态与地理研究所,荒漠与绿洲生态国家重点实验室,新疆 乌鲁木齐 830011
  • 收稿日期:2021-02-07 修回日期:2021-03-14 出版日期:2021-05-25 发布日期:2021-06-01
  • 作者简介:陈亚鹏(1979-),男,河南,副研究员,主要从事植物水分关系研究. E-mail: chenyp@ms.xjb.ac.cn
  • 基金资助:
    科技部科技基础资源调查专项(2019FY100203)

A review of water transport processes of Populus euphratica in the lower reaches of Tarim River

CHEN Yapeng(),ZHOU Honghua,ZHU Chenggang   

  1. State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, Xinjiang, China
  • Received:2021-02-07 Revised:2021-03-14 Online:2021-05-25 Published:2021-06-01

摘要:

胡杨是世界重要的林木基因资源,且具有重要的生态功能。以塔里木河下游为研究靶区,结合实地监测资料和文献阅读,对胡杨水分获取、传导和耗散等水分传输过程方面进行了综述和分析。成年胡杨主要利用地下水和深层土壤水,而幼苗由于类型和立地水土环境的不同,水分来源也不同。干旱环境下,胡杨叶片水分传输效率增加,但同时也伴随着水力失调风险的增加;成年胡杨通过下调木质部导水率减少水分蒸腾,而幼苗则通过提高导水能力以获取更多的水分。胡杨根系具有水力提升作用,提升的水量一般可为其蒸腾提供10%~39%的水量。胡杨液流通量密度一般在0.005~0.040 L·cm-2·h-1之间,且随着地下水埋深的增加而减小,胡杨林的年蒸散发量在296.7~750.0 mm之间。未来可加强胡杨根-茎-叶间水分传输互作机理的研究,进一步精确量化胡杨水分来源,将估算蒸散发的尺度扩展到胡杨林生态系统。

关键词: 胡杨, 水分传输, 干旱, 塔里木河下游

Abstract:

Populus euphratica is an important forest genetic resource in the world and has important ecological functions. Taking the lower reaches of Tarim River, Xinjiang, China as the research target, combined with field monitoring data and literature reading, we review and analyze the water transport processes, including water uptake, conduction, and dissipation, of P. euphratica. Under different habitats, the groundwater depth was closely related to the water source of P. euphratica in the lower Tarim River and determined the water use of P. euphratica. The water source of P. euphratica of different ages not only depends on its root system characteristics and types but also is controlled by the groundwater depth. Regardless of the water conditions, mature P. euphratica always mainly used groundwater. The water transport strategies of P. euphratica leaves differed under different groundwater depth conditions. When the groundwater depth increases, P. euphratica leaves not only increase their water acquisition by improving water transfer efficiency but also increase the risk of hydraulic dysfunction. Mature P. euphratica reduces water transpiration by downregulating xylem hydraulic conductivity to adapt to drought, whereas seedlings obtain more water by increasing xylem hydraulic conductivity. The root system of P. euphratica functions as a hydraulic lift, and the elevated water volume generally provides 10%-39% of its transpiration. The annual transpiration of P. euphratica stands ranged from 296.7 to 750.0 mm, with a flux density of 0.005- 0.040 L·cm-2·h-1 and decreasing with increasing groundwater depth. Furthermore, we propose the following research prospects: (1) linking the isotope technique, root morphology, groundwater depth, and water uptake to construct a quantitative analysis model with a process mechanism and explicitly quantify the water source of P. euphratica; (2) understanding the regulation mechanism of water channel proteins, osmosis, water storage, and embolism on the water transport of P. euphratica under arid environments and the adaptation mechanism of P. euphratica in water transport to the environment; (3) strengthening the integrated study of water transport processes to deeply reveal that the complex physiological processes and regulatory mechanisms of P. euphratica as the problem of the interrelationship between water acquisition, water conduction, and water dissipation in P. euphratica have not been solved; and (4) combining remote sensing, meteorological and soil data, and high-precision observation to extend the simulated scale of evapotranspiration to forest ecosystems to provide a scientific basis for regional ecological water consumption and ecological water demand.

Key words: Populus euphratica, water transport, drought, the lower reaches of Tarim River