Presence and abundance of invasive species depend on likelihood of introduction and environmental limitations to their distributions. Propagule pressure and anthropogenic disturbance are hypothesized to increase invasions, yet assessing the importance of propagule pressure and anthropogenic factors independently is challenging, and properties of invaded systems (e.g., habitat availability) likely contribute to invasions. We sampled macrophyte assemblages in 20 lakes in New York, varying in boater visitations and number of previous waterbodies visited, to test if increased propagule risk (proxy for propagule pressure measuring potential for introducing invasives from different sources) resulted in greater species richness, biomass (g/m²) and dominance (% invasive biomass) of invasive macrophytes. We then tested watershed land use, in-lake water properties, and lake morphology on presence, abundance, and dominance of invasive macrophytes. Increased propagule risk resulted in greater species richness of invasive macrophytes. In invaded lakes, increased abundance of invasive macrophytes was correlated with increased agriculture in watersheds and littoral:total area. Increased dominance of invasive macrophytes was observed in lakes with greater littoral:total areas. Results suggest propagule risk can explain spatial variability in macrophyte invasions, while area-specific biomass in invaded lakes can be correlated with watershed and in-lake water properties. In lakes with increased suitable habitat (relative proportion of littoral:total area ratio), invasive macrophytes may dominate aquatic plant assemblages. Many factors correlated with the abundance of invasive macrophytes are not easily managed (e.g., watershed agricultural land use and lake morphology). Limiting introductions of propagules is likely the best approach to prevent macrophyte invasions, especially at high risk lakes.

入侵物种的存在与丰富取决于引入的可能性和分布的环境限制。假设传播压力和人为干扰会增加入侵，但独立评估传播压力和人为因素的重要性具有挑战性，而且入侵系统的属性（例如，栖息地的可用性）可能会导致入侵。我们在纽约的20个湖中取样了大型植物群落，并进行了船夫探访和探访过的先前水体的数量各不相同，以测试繁殖风险的增加（繁殖压力的代用药测量从不同来源引入入侵物的潜力）是否导致更大的物种丰富度，生物量（克/米²）和入侵大型植物的优势度（入侵生物量百分比）。然后，我们根据入侵性大型植物的存在，丰度和优势对流域土地利用，湖内水质和湖泊形态进行了测试。繁殖风险的增加导致入侵性大型植物的物种丰富度增加。在被入侵的湖泊中，入侵性植物的丰度增加与流域和沿岸：总面积的农业增加有关。在沿岸：总面积更大的湖泊中，观察到入侵性植物的优势度增加。结果表明，繁殖风险可以解释大型植物入侵的空间变异性，而入侵湖泊中特定于区域的生物量可能与流域和湖内水质相关。在适宜栖息地增加的湖泊中（沿海地区占总面积的比例）入侵性大型植物可能在水生植物组合中占主导地位。与入侵性大型植物丰富相关的许多因素不易管理（例如流域农业土地利用和湖泊形态）。限制繁殖体的引入可能是防止大型植物入侵的最佳方法，尤其是在高风险湖泊中。