Land use changes and greater nitrogen input into waterways have facilitated the spread of an invasive Eurasian lineage of Phragmites australis across North America. Its establishment has led to decreases in wetland plant diversity, and displacement of a native American Phragmites lineage considered to be a low-nutrient specialist. We hypothesized that carbon-rich amendments that reduced nitrogen availability would competitively favor the native lineage and nitrogen additions would favor the invasive lineage. In the greenhouse we assessed competitive interactions between native and invasive lineages following sawdust (low nitrogen) and urea (high nitrogen) additions by measuring total biomass, chlorophyll fluorescence and evaluating biomass allocation. Sawdust additions did not limit invasive Phragmites growth, while urea increased aboveground biomass of both lineages. Unexpectedly, mixtures of native and invasive Phragmites produced more above and belowground biomass than monocultures. Our findings suggest that at the level examined in this study, carbon additions would not be an effective management tool to control invasive Phragmites or restore the native North American lineage, but that facilitation between native and invasive lineages could promote their coexistence across a range of nutrient availability. Our results also provide limited evidence that displacement of native Phragmites could be due to other factors such as disturbance rather than competitive exclusion.

土地用途的变化和水道中更多的氮输入促进了侵入性的欧亚芦苇世系在整个北美的传播。它的建立导致湿地植物多样性的减少，以及美洲原住民芦苇的流离失所。血统被认为是低营养专家。我们假设降低氮利用率的富含碳的改良剂竞争性地有利于天然谱系，而氮的添加则有利于侵入性谱系。在温室中，我们通过测量总生物量，叶绿素荧光和评估生物量分配，评估了添加木屑（低氮）和尿素（高氮）后本机和入侵谱系之间的竞争性相互作用。木屑的添加并不限制侵入性芦苇的生长，而尿素则增加了两个谱系的地上生物量。出乎意料的是，天然芦荟和入侵芦苇的混合物比单一栽培产生更多的地上和地下生物量。我们的研究结果表明，在本研究中研究的水平上，碳的添加不是控制入侵芦苇或恢复北美原始血统的有效管理工具，但促进原生和入侵血统之间的促进可以促进它们在多种营养素中的共存。可用性。我们的研究结果还提供了有限的证据，表明天然芦苇的移位可能是由于其他因素引起的，例如干扰而不是竞争排斥。