©2020. American Geophysical Union. All Rights Reserved. The “ecohydrologic separation” hypothesis challenged assumptions of translatory flow through the rooting zone. However, studies aiming to test ecohydrologic separation have largely done so with insufficient discussion of infiltration and rooting zone recharge processes and instead have mostly focused on either isotopic differences between stream water and plant water or the presence of fractionated isotope ratios in plant water. Based on extensively observed heterogeneities in soils and watersheds, we posit that differences in isotopic compositions of water in plants, streams, and other subsurface pools are expected in most scenarios. Interpretation of those plant-and-stream water isotopic differences is important, but diagnosing the role of any specific process is typically confounded by the diversity of potential mechanisms contributing to those isotopic differences. Thus, we should progress from simply describing their occurrences and refocus the discussion of ecohydrologic separation on how heterogeneous infiltration and root uptake processes lead to such differences. Consequently, we outline areas where plant and soil-water stable isotope data may be useful for advancing our understanding and representation of soil-water transport and plant-water recharge.

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评论：什么是生态水文分离，我们可以用它去哪里

©2020。美国地球物理联合会。版权所有。“生态水文分离”假说挑战了通过生根区平移流动的假设。然而，旨在测试生态水文分离的研究在很大程度上已经这样做了，没有充分讨论渗透和生根区补给过程，而是主要集中在溪流水和植物水之间的同位素差异或植物水中分馏同位素比率的存在上。基于在土壤和流域中广泛观察到的异质性，我们假设在大多数情况下，植物、溪流和其他地下池中水的同位素组成存在差异。对植物和河流水同位素差异的解释很重要，但诊断任何特定过程的作用通常会被导致这些同位素差异的潜在机制的多样性所混淆。因此，我们应该从简单地描述它们的发生开始，并将生态水文分离的讨论重新集中在异质渗透和根系吸收过程如何导致这种差异上。因此，我们概述了植物和土壤-水稳定同位素数据可能有助于促进我们对土壤-水运输和植物-水补给的理解和表示的领域。