Groundwater dependence of riparian woodlands and the disrupting effect of anthropogenically altered streamflow
Groundwater dependence of riparian woodlands and the disrupting effect of anthropogenically altered streamflow
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河岸林地对地下水的依赖以及人为改变的水流的破坏作用
DOI：
10.1073/pnas.2026453118
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Singer, Michael Bliss
中科院分区：
文献类型：
--
作者：
Rohde, Melissa M.;Stella, John C.;Roberts, Dar A.;Singer, Michael Bliss
河岸生态系统从根本上依赖地下水，特别是在干旱地区，但在水资源管理决策中很少考虑其水需求和水源。直到最近，技术限制和数据差距阻碍了评估地下水对河岸生态系统健康的影响，在空间和时间尺度相关的政策和管理。在这里，我们分析了哨兵-2衍生的归一化差异植被指数（NDVI;n= 5，335，472观测），基于实地的地下水位（n= 32，051观测）和径流变化数据河岸林地社区（n= 22，153多边形）在5年期间（2015年至2020年）横跨加州。我们发现，河岸林地表现出更深的地下水的压力反应，证明了同期下降的绿色代表的NDVI。此外，我们发现更大的季节性耦合冠层绿化地下水的植被沿着流与自然流动制度相比，与气候变化的溪流，特别是在最水有限的地区。这些模式表明，加州的许多河岸林地都得到了水管理实践的补贴。河岸林地社区依赖于自然变化的地下水和径流成分，以维持关键的生态过程，如招聘和演替。改变流量制度，全年稳定径流，人为地提高水供应河岸植被在旱季，扰乱了非生物驱动程序的季节性周期，这些地中海森林是适应。因此，我们的分析表明，许多河岸生态系统已成为依赖于气候变化的流量制度，使他们更容易受到影响，更不适应快速的水文变化，可能导致未来的河岸森林损失越来越强调旱地地区。
Riparian ecosystems fundamentally depend on groundwater, especially in dryland regions, yet their water requirements and sources are rarely considered in water resource management decisions. Until recently, technological limitations and data gaps have hindered assessment of groundwater influences on riparian ecosystem health at the spatial and temporal scales relevant to policy and management. Here, we analyze Sentinel-2–derived normalized difference vegetation index (NDVI;n= 5,335,472 observations), field-based groundwater elevation (n= 32,051 observations), and streamflow alteration data for riparian woodland communities (n= 22,153 polygons) over a 5-y period (2015 to 2020) across California. We find that riparian woodlands exhibit a stress response to deeper groundwater, as evidenced by concurrent declines in greenness represented by NDVI. Furthermore, we find greater seasonal coupling of canopy greenness to groundwater for vegetation along streams with natural flow regimes in comparison with anthropogenically altered streams, particularly in the most water-limited regions. These patterns suggest that many riparian woodlands in California are subsidized by water management practices. Riparian woodland communities rely on naturally variable groundwater and streamflow components to sustain key ecological processes, such as recruitment and succession. Altered flow regimes, which stabilize streamflow throughout the year and artificially enhance water supplies to riparian vegetation in the dry season, disrupt the seasonal cycles of abiotic drivers to which these Mediterranean forests are adapted. Consequently, our analysis suggests that many riparian ecosystems have become reliant on anthropogenically altered flow regimes, making them more vulnerable and less resilient to rapid hydrologic change, potentially leading to future riparian forest loss across increasingly stressed dryland regions.
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影响因子：
3.2
作者：
M. Gómez‐Sapiens;C. Jarchow;K. Flessa;P. Shafroth;E. Glenn;P. Nagler
通讯作者：
M. Gómez‐Sapiens;C. Jarchow;K. Flessa;P. Shafroth;E. Glenn;P. Nagler
影响因子：
3.2
作者：
Mayes, Marc;Caylor, Kelly K.;Nagler, Pamela
通讯作者：
Nagler, Pamela
美国加利福尼亚州水流变化的模式和幅度
DOI：
--
发表时间：
2018
期刊：
影响因子：
--
作者：
J. Zimmerman;D. Carlisle;J. May;Kirk R. Klausmeyer;T. Grantham;L. Brown;J. Howard
通讯作者：
J. Howard
DOI：
10.1073/pnas.1712381114
发表时间：
2017-10-03
影响因子：
11.1
作者：
Fan, Ying;Miguez-Macho, Gonzalo;Otero-Casal, Carlos
通讯作者：
Otero-Casal, Carlos
影响因子：
4
作者：
S. Rood;J. Braatne;F. Hughes
通讯作者：
S. Rood;J. Braatne;F. Hughes