Anthropogenic land-use change impacts ecological communities in urban and rural landscapes, and wetlands are particularly vulnerable despite the valuable ecosystem services they provide. Urbanized non-wetland systems are often enriched in non-native plant species, and similar patterns in wetlands would have implications for ecosystem function and biodiversity. We evaluated landscape-scale patterns of plant community diversity across gradients of rural to urban land-use, testing whether diversity was related to environmental conditions indicative of surrounding land-use. We surveyed vegetation and collected soil samples from 45 wetlands throughout Ohio, USA. Sites were categorized based on surrounding land-use as intense urban, moderate urban, or rural, representing 15 replicate urban to rural gradients. Non-native richness was 56% greater and non-native relative abundance 74% greater in intense urban sites compared to rural sites. Structural equation modeling indicated that high non-native relative abundance caused reductions in native plant richness but not native Shannon diversity, which was instead related to high concentrations of urban-associated soil contaminants such as cadmium and sodium. Our results support both versions of the driver-passenger model of invasion impacts, depending on the response: native richness is directly limited by competition with non-native species (the driver model), while native diversity is limited more by urban-associated stressors that also affect non-natives (the passenger model). The few wetlands remaining in highly urban areas thus experience a range of constraints affecting multiple dimensions of wetland health. We argue it is in these sites specifically where the benefits of restoring wetland ecosystems will be maximized.

人为的土地利用变化影响到城市和乡村景观中的生态社区，尽管湿地提供了宝贵的生态系统服务，但它们尤其脆弱。城市化的非湿地系统通常富含非本地植物物种，而湿地中的类似模式将对生态系统功能和生物多样性产生影响。我们评估了从农村到城市土地利用梯度的植物群落多样性的景观尺度格局，测试了多样性是否与指示周围土地利用的环境条件有关。我们调查了植被，并从美国俄亥俄州的45个湿地中收集了土壤样本。根据周围的土地用途，将地点分类为密集的城市，中度城市或农村，代表15个重复的城市到农村梯度。与农村地区相比，城市密集地区的非本地居民富裕度高56％，非本地居民相对富裕度高74％。结构方程模型表明，较高的非本地相对丰度导致本地植物丰富度降低，但本地香农多样性并未降低，这与高浓度的城市相关土壤污染物（例如镉和钠）有关。我们的研究结果支持两种形式的入侵影响驾驶员/乘客模型，具体取决于响应方式：本地人的富裕程度直接受到与非本地物种的竞争的限制（驾驶员模型），而本地多样性则受到与城市相关的压力源的更多限制，即也影响非本地人（乘客模型）。因此，留在高度城市地区的少数湿地受到一系列影响湿地健康的多个方面的制约。我们认为，正是在这些地点中，恢复湿地生态系统的利益才能最大化。