Our study of a St. Lawrence Estuary marsh reveals that, compared to native Spartina patens ‐dominated vegetation, invasive Phragmites australis makes a greater contribution to soil volume and carbon stock (referred to as blue carbon). Phragmites ' contributions to soil volume enhance marsh sustainability in face of sea level rise, and its greater contribution to soil carbon helps to reduce the atmospheric concentration of CO₂. Phragmites australis (common reed) is a cosmopolitan species growing in fresh to brackish wetlands. An invasive genetic strain, introduced from Europe or Asia, has expanded extensively along the St. Lawrence River in the last few decades but has been little studied on the estuarine portion. We collected soil cores from three sites within an invasive Phragmites stand and one site within S. patens ‐dominated stand in a St. Lawrence Estuary salt marsh near la Pocatiere, Quebec. We measured the bulk density, carbon content, volume, and mass of belowground organic matter in 2‐cm‐thick soil layers of three cores at each Phragmites site. Bulk density and carbon content were measured in 5‐cm‐thick soil layers of three cores at S. patens site. Results showed that soil in the Phragmites stands held 37–77% more blue carbon than in the S. patens ‐dominated marsh. Based upon their diameter size, Phragmites rhizomes could be contributing 7.4–10.2 cm to the thickness in the upper 20 cm of soil. We suggest that any management of invasive Phragmites include consideration of its role in increasing blue carbon stocks and marsh resilience along with other ecosystem services.

中文翻译：

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入侵的芦苇增加了圣劳伦斯河口沼泽中的蓝色碳储量和土壤体积

我们一圣劳伦斯河河口湿地的研究表明，相对于原生狐米草-dominated植被，侵入芦苇品牌土壤量和碳储量（简称兰炭），更大的贡献。面对海平面上升，芦苇对土壤量的贡献增强了沼泽的可持续性，而对土壤碳的更大贡献则有助于降低大气中的CO ₂浓度。芦苇（普通芦苇）是在新鲜到微咸的湿地中生长的世界性物种。在过去的几十年中，从欧洲或亚洲引入的一种侵入性遗传菌株在圣劳伦斯河沿岸广泛传播，但对河口部分的研究很少。我们从魁北克省拉波卡蒂埃（La Pocatiere）附近的圣劳伦斯河口盐沼中的侵入芦苇林分的三个地点和以S. patens为主的林分的一个地点收集了土壤核心。我们在每个芦苇地的三个岩心的2厘米厚的土壤层中测量了地下有机物的堆密度，碳含量，体积和质量。在S. patens的三个岩心的5厘米厚的土壤层中测量堆密度和碳含量现场。结果显示，在土壤芦苇看台持有37-77％的兰炭比S.藓-dominated沼泽。根据它们的直径大小，芦苇的根茎可能对土壤上部20 cm的厚度贡献7.4-10.2 cm。我们建议对入侵芦苇的任何管理都应考虑其在增加蓝碳储量和沼泽抗灾力以及其他生态系统服务中的作用。