Oxbow wetlands have been restored in the Midwestern United States to provide habitat for wetland-dependent species and to sequester contaminants originating from agricultural activities. Intensive agriculture may have adverse impacts on oxbow functions, especially if wetlands receive water inputs from subsurface drainage systems (e.g., tile drainage). To explore the influence of tile drainage on oxbow wetland communities, we quantified relationships between physical and biotic variables in 12 Iowa, USA oxbows over a two-year period (June to August 2019–2020). Six oxbows received direct water inputs from tile drainage (multipurpose oxbows), whereas remaining sites did not (non-tiled oxbows). In each oxbow, we measured physical variables and documented taxonomic composition, diversity, and abundance of macrophytes, macroinvertebrates, and fishes. Although water temperature was lower in multipurpose oxbows, values for other physical variables (e.g., turbidity, conductivity, and total dissolved solids) were similar across sites. No significant difference was detected for any biotic variable between oxbow types. In total, we observed 44 invertebrate taxa in both oxbow types with an average richness of 18.6 in non-tiled oxbows and 17.5 in tile-fed oxbows. We sampled 35 fish species, with an average richness across sampling dates of 8.2 in non-tiled oxbows and 11.4 in multipurpose oxbows. A total of 2682 Topeka shiners were found in both non-tiled and multipurpose oxbows. Non-metric multidimensional scaling revealed that potential physical determinants of macrophyte, invertebrate, and fish abundance were unrelated to tile drainage. Tile drainage had negligible impacts on coarse physical characteristics, taxa richness (fish and macroinvertebrates) and abundance (fish and macroinvertebrates).

美国中西部的 Oxbow 湿地已得到恢复，为依赖湿地的物种提供栖息地，并隔离农业活动产生的污染物。集约化农业可能会对牛轭功能产生不利影响，特别是如果湿地从地下排水系统（例如瓷砖排水系统）接收水输入。为了探讨瓷砖排水对牛轭湿地群落的影响，我们量化了美国爱荷华州 12 个牛轭湿地两年期间（2019 年 6 月至 2020 年 8 月）的物理变量和生物变量之间的关系。六个牛轭区从瓷砖排水系统（多用途牛轭区）直接接收水输入，而其余地点则没有（非瓷砖牛轭区）。在每个牛弓中，我们测量了物理变量并记录了大型植物、大型无脊椎动物和鱼类的分类组成、多样性和丰度。尽管多用途牛轭水温较低，但其他物理变量（例如浊度、电导率和总溶解固体）的值在各个地点都相似。牛弓类型之间的任何生物变量均未检测到显着差异。总的来说，我们在两种牛弓类型中观察到了 44 个无脊椎动物类群，其中非平铺牛弓的平均丰富度为 18.6，平铺牛弓的平均丰富度为 17.5。我们对 35 种鱼类进行了采样，在采样日期中，非平铺牛轭鱼的平均丰富度为 8.2，多用途牛轭鱼的平均丰富度为 11.4。在非瓷砖和多用途牛弓中总共发现了 2682 个托皮卡闪光器。非度量多维标度表明，大型植物、无脊椎动物和鱼类丰度的潜在物理决定因素与排水无关。瓦片排水对粗略的物理特征、类群丰富度（鱼类和大型无脊椎动物）和丰度（鱼类和大型无脊椎动物）的影响可以忽略不计。