When do plant hydraulics matter in terrestrial biosphere modelling?
When do plant hydraulics matter in terrestrial biosphere modelling?
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DOI：
10.1111/gcb.17022
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发表时间：
2023-11
影响因子：
11.6
通讯作者：
A. Paschalis;M. D. De Kauwe;M. Sabot;Simone Fatichi
中科院分区：
文献类型：
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作者：
A. Paschalis;M. D. De Kauwe;M. Sabot;Simone Fatichi
植物水力学研究所描述的水分从土壤上升到维管植物的叶子，调节生态系统对环境胁迫的反应和从胁迫期的恢复。已经提出了几种方法来模拟工厂水力学。在这项研究中，我们介绍了四个不同版本的植物水力学表示在陆地生物圈模型T&C了解植物水力学生态系统功能的意义。我们测试了植物水力学的表现，调查了植物水容量，以及干旱后的长期木质部损伤。我们测试的四个模型是包括或忽略电容和包括或忽略木质部损伤遗产的表示的组合。使用模型在六个案例研究跨越半干旱到热带生态系统，我们量化了植物木质部流动，植物水分储存和长期木质部损伤如何在多个时间尺度上调节整体水和碳动态。我们表明，随着干旱的发展，植物水力学模型预测植物水分胁迫的发生速度会减慢，并且水和碳通量的日变化更接近观察结果。植物储水被认为是特别重要的昼夜动态的水和碳通量，模型，包括植物水容量产生更好的结果。包括传导植物组织的永久性损伤的模型显示出额外的显著干旱遗留效应，在重大干旱后的恢复阶段限制了植物生产力。然而，当考虑生态系统对观测到的气候变率的响应时，单独的植物水力模块不能显着提高整体模型的性能，即使它们再现了更真实的水和碳动态。这为模型开发开辟了新的途径，明确地将植物水力学与其他生态系统过程联系起来，例如植物物候学和改进的碳分配算法。
The ascent of water from the soil to the leaves of vascular plants, described by the study of plant hydraulics, regulates ecosystem responses to environmental forcing and recovery from stress periods. Several approaches to model plant hydraulics have been proposed. In this study, we introduce four different versions of plant hydraulics representations in the terrestrial biosphere model T&C to understand the significance of plant hydraulics to ecosystem functioning. We tested representations of plant hydraulics, investigating plant water capacitance, and long‐term xylem damages following drought. The four models we tested were a combination of representations including or neglecting capacitance and including or neglecting xylem damage legacies. Using the models at six case studies spanning semiarid to tropical ecosystems, we quantify how plant xylem flow, plant water storage and long‐term xylem damage can modulate overall water and carbon dynamics across multiple time scales. We show that as drought develops, models with plant hydraulics predict a slower onset of plant water stress, and a diurnal variability of water and carbon fluxes closer to observations. Plant water storage was found to be particularly important for the diurnal dynamics of water and carbon fluxes, with models that include plant water capacitance yielding better results. Models including permanent damage to conducting plant tissues show an additional significant drought legacy effect, limiting plant productivity during the recovery phase following major droughts. However, when considering ecosystem responses to the observed climate variability, plant hydraulic modules alone cannot significantly improve the overall model performance, even though they reproduce more realistic water and carbon dynamics. This opens new avenues for model development, explicitly linking plant hydraulics with additional ecosystem processes, such as plant phenology and improved carbon allocation algorithms.