Solute evidence for hydrological connectivity of geographically isolated wetlands
Solute evidence for hydrological connectivity of geographically isolated wetlands
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地理上孤立的湿地水文连通性的确凿证据
DOI：
10.1002/ldr.3145
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发表时间：
2018
影响因子：
4.7
通讯作者：
J. Jarsjö
中科院分区：
文献类型：
--
作者：
J. Thorslund;M. Cohen;J. Jawitz;G. Destouni;I. Creed;M. Rains;P. Badiou;J. Jarsjö
水文连通性描述了以水为媒介的质量、能量和生物在景观要素之间的转移，是理解湿地和溪流等单个要素如何整合以支持景观中的生态系统服务和基于自然的解决方案的基础。地理上孤立的湿地(GIW)--即没有持续地表水连接的湿地--的水文连通性尤其鲜为人知。为了更好地了解GIW的水文连通性，我们使用一种新的氯离子质量平衡方法来量化北美260 GW子流域的当地径流产生量(定义为降雨量减去蒸散量，假设长期蓄水量可以忽略不计)。为了评估水文连通性，我们将GIW子流域的估计局部径流与集水区平均径流进行比较。这些比较提供了关于全球水文系统连通性的大小和可变性的三个新的见解。首先，在10个研究区域中，GIW次集水区产生的径流量是平均集水率的120%，这意味着它们是更大的水文景观中连接良好的元素。第二，GIW各分流域之间的径流产生量有很大的异质性，这可能支持一系列广泛的生态系统功能和服务。最后，观测到的径流产生的非均质性与简单的线性地理预测因子基本不相关，这表明GIW景观位置不能可靠地预测水文连通性。与先验的法律假设形成鲜明对比的是，GIW表现出较低的水文连通性或没有水文连通性，我们的结果表明GIW子流域是径流产生中活跃的景观特征。
Hydrological connectivity describes the water‐mediated transfer of mass, energy, and organisms between landscape elements and is the foundation for understanding how individual elements such as wetlands and streams integrate to support ecosystem services and nature‐based solutions in the landscape. Hydrological connectivity of geographically isolated wetlands (GIWs)—that is, wetlands without persistent surface water connections—is particularly poorly understood. To better understand GIW hydrological connectivity, we use a novel chloride mass‐balance approach to quantify the local runoff generation (defined as precipitation minus evapotranspiration, assuming negligible long‐term water storage) for 260 GIW subcatchments across North America. To evaluate hydrological connectivity, we compare the estimated local runoff from GIW subcatchments with the catchment‐average runoff. These comparisons provide three novel insights regarding the magnitude and variability of GIW hydrological connectivity. First, across 10 study regions, GIW subcatchments generate runoff at 120% of the mean catchment rate, implying they are well‐connected elements of the larger hydrologic landscape. Second, there is substantial heterogeneity in runoff generation among GIW subcatchments, which may enable support for a wide array of ecosystem functions and services. Finally, observed heterogeneity in runoff generation was largely uncorrelated to simple linear geographic predictors, indicating that GIW landscape position cannot reliably predict hydrological connectivity. In stark contrast to a priori legal assumptions that GIWs exhibit low or no hydrological connectivity, our results suggest that GIW subcatchments are active landscape features in runoff generation.