Plant functional connectivity integrates species-environment interactions, dispersal vectors, and landscape structure variables to understand species’ spatial responses to habitat fragmentation. Functional connectivity is still poorly understood for aquatic plants despite the promise it holds for informing wetland conservation across landscapes. Through a landscape genetics approach, we quantified plant functional connectivity among geographically isolated wetlands by genotyping seven nuclear microsatellite loci in 18 populations of Nymphoides fallax, a tetraploid aquatic plant endemic to Mexican and Guatemalan highland wetlands. We tested if wetland connectivity, quantified with three connectivity indices, translated to high genetic diversity within populations and if geographical distance per se explained gene flow among wetlands. We also tested if landscape features such as vegetation and surface water cover explained gene flow among N. fallax populations. Our results show that wetland connectivity is positively associated with genetic diversity over threshold distances up to 5 km. The S_i Hanski connectivity index, with wetland area incorporated, was the best predictor explaining the effective number of alleles, allelic richness, and expected heterozygosity. Population-specific F_ST, as a proxy for gene flow, was better explained by a model including forest cover than by geographical distance or water cover. Our findings highlight the importance of forest conservation to maintain gene flow at the landscape scale for N. fallax and allows the detection of key populations to maintain genetic diversity and connectivity. Understanding wetland connectivity is critical to address wetland loss in human-impacted landscapes.

植物功能的连通性整合了物种与环境的相互作用，扩散媒介和景观结构变量，以了解物种对生境破碎化的空间响应。尽管对水生植物的功能连通性有保证为整个景观提供湿地保护的承诺，但对功能连通性的理解仍然很少。通过景观遗传学方法，我们通过对18个Nymphoides fallax（墨西哥和危地马拉高地湿地特有的四倍体水生植物）种群中的七个核微卫星基因座进行基因分型，从而量化了地理上孤立的湿地之间的植物功能连通性。我们测试了湿地连通性（是否用三个连通性指数进行了量化）是否转化为种群内部的高度遗传多样性以及本身的地理距离解释了湿地之间的基因流动。我们还测试了植被和地表水覆盖等景观特征是否能解释北落叶杆菌种群之间的基因流动。我们的研究结果表明，湿地的连通性在5公里以内的阈值距离内与遗传多样性呈正相关。该小号_我Hanski连接性指数，与湿地区域掺入，是最好的预测解释有效等位基因数，等位基因丰度，和期望杂。具体人口˚F _ST，作为基因流的替代，用森林覆盖率模型来解释比用地理距离或水覆盖率更好。我们的发现凸显了森林保护对于保持法拉第猪笼草景观规模的基因流的重要性，并允许检测关键种群以维持遗传多样性和连通性。了解湿地的连通性对于解决人类影响景观中的湿地流失至关重要。