Abstract Living shoreline marshes are coastal wetlands constructed as alternatives to “hardened shorelines” (e.g., bulkheads, riprap) to mitigate erosion and to allow for landward migration of intertidal habitat as sea level rises. Living shorelines are designed to mimic natural fringing marshes and over time should be sinks for carbon and other nutrients. We collected soil cores and aboveground plant material from 13 pairs of natural fringing marshes and living shoreline marshes of different ages and degree of isolation from more extensive marsh shorescapes to compare nutrient pools and accrual. Although the nutrient content of plants was similar within and between marsh types, soil nutrients were variable from both living shorelines aged 2–16 years and long-established natural marshes. Most—but not all—living shoreline marshes had lower soil organic content, higher bulk density, and lower soil % carbon, nitrogen and phosphorus than their natural marsh pair. Variation in soil nutrients from living shorelines was not strongly correlated with either marsh age or degree of isolation in the estuarine shorescape. Assuming constant accrual within individual marshes, we estimated soil nutrient levels in living shorelines would approach those observed in their paired, natural fringing marshes over timescales from less than 10 years to many decades. Living shoreline marshes are on trajectories to match natural marsh function with respect to carbon and nutrient storage in estuarine systems.

中文翻译：

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人工海岸线与天然边缘沼泽地养分积累比较

摘要 有生命的海岸线沼泽是海岸湿地，作为“硬化海岸线”（例如，隔板、抛石）的替代品，以减轻侵蚀并允许潮间带栖息地随着海平面上升而向陆地迁移。有生命的海岸线旨在模仿自然边缘沼泽，随着时间的推移，应该成为碳和其他营养物质的汇。我们从更广泛的沼泽海岸景观中收集了 13 对不同年龄和隔离程度的天然边缘沼泽和生活海岸线沼泽的土壤核心和地上植物材料，以比较养分库和增长。尽管沼泽类型内部和沼泽类型之间植物的养分含量相似，但土壤养分在 2-16 年的生活海岸线和长期建立的天然沼泽中是可变的。大多数（但不是全部）生活的海岸线沼泽比它们的天然沼泽具有更低的土壤有机含量、更高的容重和更低的土壤碳、氮和磷百分比。生活海岸线土壤养分的变化与沼泽年龄或河口海岸景观的隔离程度没有很强的相关性。假设单个沼泽内不断增加，我们估计活海岸线的土壤养分水平将接近在不到 10 年到数十年的时间尺度内在成对的天然边缘沼泽中观察到的水平。有生命的海岸线沼泽在河口系统的碳和养分储存方面与自然沼泽功能相匹配。生活海岸线土壤养分的变化与沼泽年龄或河口海岸景观的隔离程度没有很强的相关性。假设单个沼泽地不断增加，我们估计活海岸线的土壤养分水平将接近在不到 10 年到数十年的时间尺度内在成对的自然边缘沼泽中观察到的水平。有生命的海岸线沼泽在河口系统的碳和养分储存方面与自然沼泽功能相匹配。生活海岸线土壤养分的变化与沼泽年龄或河口海岸景观的隔离程度没有很强的相关性。假设单个沼泽地不断增加，我们估计活海岸线的土壤养分水平将接近在不到 10 年到数十年的时间尺度内在成对的自然边缘沼泽中观察到的水平。有生命的海岸线沼泽在河口系统的碳和养分储存方面与自然沼泽功能相匹配。自然边缘沼泽的时间跨度从不到 10 年到数十年不等。有生命的海岸线沼泽在河口系统的碳和养分储存方面与自然沼泽功能相匹配。自然边缘沼泽的时间跨度从不到 10 年到数十年不等。有生命的海岸线沼泽在河口系统的碳和养分储存方面与自然沼泽功能相匹配。