植物吸收的土壤水的时空起源
Gonzalo Miguez-Macho1, Ying Fan2
1CRETUS, Non-Linear Physics Group, Faculty of Physics, Universidade de Santiago de Compostela, Galicia, Spain. gonzalo.miguez@usc.es.
Nature
|October 7, 2021
概括
植物主要利用当前的降水进行透汗,但在干旱期间会利用更深的土壤和地下水源. 了解这些多样化的水源对于管理生态系统和改善地球系统模型至关重要.
科学领域:
- 水文和生态系统科学
- 植物生理和生态
- 地球系统科学
背景情况:
- 植物在调节地球的水,能量和碳循环中起着至关重要的作用.
- 植物对干旱的反应,包括吸收水的变化,对于理解未来的生态系统功能至关重要.
- 之前的研究表明, 在干旱时期, 植被可以获得更深的土壤水分, 岩石水分和地下水.
研究的目的:
- 区分和评估四种不同的水源的植物利用情况:当前降水,储存的土壤/岩石水分,当地地下水和偏远的地下水.
- 调查植物用水源的全球和季节性模式和驱动因素.
- 为生态系统管理和地球系统建模提供连接降水和植被的水文路径的见解.
主要方法:
- 采用反向建模技术来分析植物的吸水量.
- 使用基于同位素的估计来量化不同水源的贡献.
- 研究了各种气候和景观类型的全球和季节性模式.
主要成果:
- 在全球范围内,70%的植物透气使用当前降水 (来源1),18%使用储存的深水 (来源2),1%使用本地地下水 (来源3),10%使用偏远的地下水 (来源4).
- 季节性地,在最干旱的月份,在半干旱地区 (19%) 和地中海地区 (32%) 和热带地区 (17%) 的第一来源贡献显著下降.
- 在景观尺度上,较深的土壤水 (来源2) 对高原至关重要,而偏远的地下水 (来源4) 在山谷和绿洲中具有重要意义 (高达47%).
结论:
- 植物的水源利用量因地区,季节和景观位置而异.
- 在干旱时期,土壤水分和地下水变得越来越重要,特别是在特定的景观特征中.
- 了解植物水源的时空起源对于准确的生态系统管理和地球系统建模至关重要.
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