The intermixed cropland, grassland, and wetland ecosystems of the upper mid-western United States combine to provide a suite of valuable ecological services. Grassland and wetland losses in the upper midwestern United States have been extensive, but government-funded conservation programs have protected and restored hundreds of thousands of acres of wetland and grassland habitat in the region. The value of restored wetlands in agricultural fields is complex, and the USDA Natural Resource Conservation Service, Conservation Effects Assessment Project (CEAP) has been lacking the methodology to include these conservation practices in their analyses. Our aim is to develop a reproducible methodology for simulating wetlands within the CEAP cropland modeling framework used to evaluate other agricultural conservation practices. Furthermore, we evaluate the effect of using upland conservation practices on the functioning of restored wetlands. By simulating the addition of a depressional wetland that effectively removes 6% of the field from crop production, we obtained a 15% reduction in annual runoff and a 29% and 28% reduction in mean annual nitrogen (N) and phosphorus (P) losses, respectively. The presence of the depressional wetland in the field is estimated to also reduce edge-of-field losses of sediments by 20% and sediment-bound N and P by 19% and 23%, respectively. Additionally, adding a grass filter strip around the wetland greatly decreased sediment inputs to the wetland, increasing the effective life of the wetland, in terms of its ability to perform valued services, by decades to centuries. Our method for modeling depressional wetlands embedded in cropped fields provides a means to quantify the effects of wetland conservation practices on field-level losses for regional assessments, such as the CEAP.

中文翻译：

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开发用于模拟农业景观中洼地湿地的田间规模保护效应的新框架

美国中西部混合的农田、草地和湿地生态系统相结合，提供了一套有价值的生态服务。美国中西部上游的草地和湿地损失非常广泛，但政府资助的保护计划保护并恢复了该地区数十万英亩的湿地和草地栖息地。农田中恢复湿地的价值是复杂的，美国农业部自然资源保护局保护效果评估项目 (CEAP) 一直缺乏将这些保护实践纳入其分析的方法。我们的目标是在用于评估其他农业保护实践的 CEAP 农田建模框架内开发一种可重复的方法来模拟湿地。此外，我们评估了使用高地保护措施对恢复湿地功能的影响。通过模拟增加一个洼地湿地，该湿地有效地从作物生产中去除了 6% 的田地，我们使年径流减少了 15%，年平均氮 (N) 和磷 (P) 损失减少了 29% 和 28% ， 分别。据估计，田间洼地湿地的存在还将使沉积物的田边损失减少 20%，沉积物结合的 N 和 P 分别减少 19% 和 23%。此外，在湿地周围添加草过滤带大大减少了对湿地的沉积物输入，将湿地的有效寿命（就其提供有价值的服务的能力而言）延长了几十到几个世纪。