Resetting of soil compositions by irrigation in urban watersheds: Evidence from Sr isotope variations in Austin, TX
Resetting of soil compositions by irrigation in urban watersheds: Evidence from Sr isotope variations in Austin, TX
复制标题
城市流域灌溉重置土壤成分：来自德克萨斯州奥斯汀市锶同位素变化的证据
DOI：
10.1016/j.scitotenv.2023.166928
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发表时间：
2023
影响因子：
9.8
通讯作者：
Banner, Jay L.
中科院分区：
文献类型：
--
作者：
Mauceri, Alessandro A.;Banner, Jay L.
城市地区的人类活动扰乱了它们赖以发展的自然景观，扰乱了成壤过程，最终限制了城市土壤提供的生态系统服务。为了更好地了解城市发展对土壤的影响和弹性，有必要了解城市系统中土壤物理和化学性质改变的过程和程度。在这里，我们应用锶同位素(87Sr/86Sr)的溯源能力来了解城市进程对德克萨斯州奥斯汀八个流域土壤成分的影响。我们评估了跨越广泛城市化的流域中的自然和人为锶来源，通过比较土壤的自然(包括矿物学、厚度、土壤类型和流域)和人为(包括灌溉、土壤改良和施肥)特征的变化来比较土壤。旱地土壤厚度与~(87)Sr/~(86)Sr比值呈极显著正相关(R2=0.83)。相反，在灌溉土壤中没有观察到这种关系(R2=0.0.004)。在42个灌溉土样中，95%的土壤87Sr/86Sr值接近或在市政供水范围内。这些结果表明，土壤通过灌溉和/或水利基础设施渗漏与城市水相互作用。在8个流域中，有7个用城市水灌溉的土壤比未灌溉土壤的87锶/86锶值高。我们认为，通过离子交换过程用城市水灌溉，可以部分或完全地重置原始土壤的~(87)Sr/~(86)锶。我们的结果表明，在城市系统中，锶同位素可以作为环境示踪剂来评估城市化对自然土壤特性的叠加。在奥斯汀地区，通过城市发展重新调整自然土壤组成的情况很广泛，城市地区和灌溉系统的持续扩张可能会影响土壤保持养分、过滤污染物和提供支持环境弹性的其他生态系统服务的能力。
Human activities in urban areas disturb the natural landscape upon which they develop, disrupting pedogenic processes and ultimately limiting the ecosystem services urban soils provide. To better understand the impacts on and resiliency of soils in response to urban development, it is essential to understand the processes by which and degree to which soil physical and chemical properties are altered in urban systems. Here, we apply the source-tracing capabilities of Sr isotopes (87Sr/86Sr) to understand the impacts of urban processes on the composition of soils in eight watersheds in Austin, Texas. We evaluate natural and anthropogenic Sr sources in watersheds spanning a wide range of urbanization, comparing soils by variations in their natural (including mineralogy, thickness, soil type, and watershed) and anthropogenic (including irrigation, soil amendments, and fertilization) characteristics. A strong positive correlation between soil thickness and87Sr/86Sr is observed among unirrigated soils (R2= 0.83). In contrast, this relationship is not observed among irrigated soils (R2= 0.004). 95 % of 42 irrigated soil samples have87Sr/86Sr values approaching or within the range for municipal supply water. These results indicate soil interaction with municipal water through irrigation and/or water infrastructure leakage. Soils irrigated with municipal water have elevated87Sr/86Sr values relative to unirrigated soils in seven of eight watersheds. We propose that original soil87Sr/86Sr values are partially to completely reset by irrigation with municipal water via ion exchange processes. Our results demonstrate that in urban systems, Sr isotopes can serve as an environmental tracer to assess the overprint of urbanization on natural soil characteristics. In the Austin region, resetting of natural soil compositions via urban development is extensive, and the continued expansion of urban areas and irrigation systems may affect the ability of soils to retain nutrients, filter contaminants, and provide other ecosystem services that support environmental resilience.