Canopy Height and Climate Dryness Parsimoniously Explain Spatial Variation of Unstressed Stomatal Conductance
Canopy Height and Climate Dryness Parsimoniously Explain Spatial Variation of Unstressed Stomatal Conductance
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DOI：
10.1029/2022gl099339
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发表时间：
2022-07
影响因子：
5.2
通讯作者：
Yanlan Liu;Olivia Flournoy;Quan Zhang;K. Novick;R. Koster;A. Konings
中科院分区：
文献类型：
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作者：
Yanlan Liu;Olivia Flournoy;Quan Zhang;K. Novick;R. Koster;A. Konings
气孔导度的时空变化直接调节光合作用、水分分配和生物圈-大气相互作用。虽然许多研究都集中在气孔对胁迫的反应，非胁迫气孔导度的空间变化仍然很难确定，通常是简单地基于植物功能型（PFT）的陆面模型（LSMs）的特点。在这里，我们使用来自115个全球FLUXNET站点的观测结果推导出生态系统尺度的无应力气孔导度。当通过PFT聚合时，跨PFT模式与LSM的参数化高度一致。然而，PFTs单独捕获只有17%的变化，在无压力的气孔导度跨网站。在同一PFT内，非胁迫气孔导度与气候干燥度和冠层高度呈负相关，解释了总空间变异的45%。我们的研究结果强调了植物环境相互作用在塑造气孔特征中的重要性。本文建立的性状-环境关系为LSM气孔导度的参数化提供了一种经验方法。
The spatio‐temporal variation of stomatal conductance directly regulates photosynthesis, water partitioning, and biosphere‐atmosphere interactions. While many studies have focused on stomatal response to stresses, the spatial variation of unstressed stomatal conductance remains poorly determined, and is usually characterized in land surface models (LSMs) simply based on plant functional type (PFT). Here, we derived unstressed stomatal conductance at the ecosystem‐scale using observations from 115 global FLUXNET sites. When aggregated by PFTs, the across‐PFT pattern was highly consistent with the parameterizations of LSMs. However, PFTs alone captured only 17% of the variation in unstressed stomatal conductance across sites. Within the same PFT, unstressed stomatal conductance was negatively related to climate dryness and canopy height, which explained 45% of the total spatial variation. Our results highlight the importance of plant‐environment interactions in shaping stomatal traits. The trait‐environment relationship established here provides an empirical approach for improved parameterizations of stomatal conductance in LSMs.