Shoreline hardening affects ecological processes in nearshore intertidal ecosystems and upland habitats. Invasive species establishment and spread is one consequence of shoreline alterations. Invasive Phragmites australis has spread throughout the U.S., including in subestuaries with hardened shorelines. It is unclear, though, by what mechanisms shoreline hardening facilitates P. australis establishment. We tested the hypothesis that shoreline structures are associated with seedling recruitment, resulting in higher levels of within stand genetic diversity. We used microsatellite analysis to examine the genetic diversity of P. australis stands associated with two types of shoreline structures (riprap, bulkhead revetments) compared to unaltered shorelines. Because P. australis seed viability depends on cross-pollination, higher levels of genetic diversity in stands associated with hardened shorelines are more likely to contribute to the spread of invasive P. australis. We conclude that the extent of shoreline modifications in the Chesapeake Bay has contributed to the spread of P. australis by seeds. The results have implications for the management of P. australis associated with the establishment of shoreline structures.

海岸线硬化影响近岸潮间带生态系统和高地栖息地的生态过程。入侵物种的建立和传播是海岸线变化的结果之一。侵袭性芦苇已遍布美国，包括在海岸线硬化的河口。但是，尚不清楚海岸线硬化通过何种机制促进澳大利亚假单胞菌的建立。我们检验了海岸线结构与幼苗募集相关的假设，从而导致林分遗传多样性较高。我们使用微卫星分析来检查澳大利亚对虾的遗传多样性与未更改的海岸线相比，与两种类型的海岸线结构（翻石，舱壁护岸）相关的林分。由于P. australis种子的生存能力取决于异花授粉，因此与硬化海岸线相关的林分中较高的遗传多样性水平更可能有助于入侵性P的传播。澳大利亚。我们得出的结论是，切萨皮克湾海岸线变化的程度促进了种子对南美假单胞菌的传播。结果对P的管理具有重要意义。与海岸线结构的建立相关的澳大利亚。