根深深地减轻干旱对热带树木的影响,尽管对透气的定量贡献有限
Kathrin Kühnhammer1, Joost van Haren2, Angelika Kübert3
1IGOE, Environmental Geochemistry, TU Braunschweig, Langer Kamp 19c, 38106 Braunschweig, Germany; Ecosystem Physiology, University of Freiburg, Georges-Köhler-Allee 53/54, 79110 Freiburg, Germany.
The Science of the total environment
|June 12, 2023
概括
热带树木在干旱期间利用深深的根源获取水,获得高达3.3米的水. 然而,由于干旱期间树木水流量减少,总体深水吸收受到限制.
科学领域:
- 生态生态学 生态生态学
- 植物生理学 植物生理学
- 水文学的水文学
背景情况:
- 根深蒂固对于干旱缓解和生态系统水循环至关重要.
- 人们对水的量化使用和深层根的深度转移动力学知之甚少,特别是在热带树木中.
研究的目的:
- 在干旱和重新灌事件期间调查热带树木对深水的吸收.
- 量化深层根对整体用水和透气的贡献.
主要方法:
- 在生物圈2热带雨林中进行了一项干旱,深层土壤水标记和重新灌的实验.
- 在土壤和树木水中的水稳定同位素的现场测量以高时间分辨率进行.
- 土壤和树干水含量和汁液流量测量补充了同位素分析,以确定深水吸收动态.
主要成果:
- 所有的树冠树都能进入深水 (深度高达3.3米),在干旱期间为透气贡献21-90%.
- 深层土壤水对热带树木至关重要,防止水位和茎水含量的有害下降.
- 尽管获得了水,但由于干旱期间水汁流量减少,深水的数量吸收量很低;随着水的可用性,吸收量动态转移.
结论:
- 深层土壤水是热带树木的重要资源,可以减轻干旱的影响.
- 气候变化引起的干旱可能会被深层水源的获取部分缓解.
- 降水输入仍然是热带森林中总透气流的主要驱动因素.
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