The western basin of Lake Erie, the shallowest of the Laurentian Great Lakes in North America, is now plagued by harmful algal blooms annually due to nutrient discharges primarily from its basin. Water quality was impacted so significantly by toxic cyanobacteria in 2014 that the city of Toledo’s water supply was shut off, affecting hundreds of thousands of residents. A new agricultural land management approach, ‘wetlaculture (=wetland + agriculture)’, has a goal of reducing the need for fertilizer applications while preventing fluxes of nutrients to downstream aquatic ecosystems. A wetlaculture mesocosm experiment was set up on agricultural land near Defiance, Ohio, on the northwestern edge of the former ‘Great Black Swamp’. The mesocosms were randomly assigned to four hydrologic treatments involving two water depths (no standing water and ~10-cm of standing water) and two hydraulic loading rates (10 and 30 cm week⁻¹). Nearby agricultural ditch water was pumped to provide weekly hydraulic loading rates to the mesocosms. During the two-year period, the net mass retention of phosphorus from the water was estimated to have averaged 1.0 g P m⁻² in the wetland mesocosms with a higher hydraulic loading rate, while the highest estimated net nitrogen mass retention (average 22 g N m⁻²) was shown in the wetland mesocosms with 10 cm of standing water and higher hydraulic loading rate. Our finding suggests that hydrologic conditions, especially water level, contribute directly and indirectly to nutrient retention, partially through the quick response of the wetland vegetation community. This study provides valuable information for scaling up to restore significant areas of wetlaculture/wetlands in the former Great Black Swamp, strategically focused on reducing the nutrient loading to western Lake Erie from the Maumee River Basin.

中文翻译：

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在前伊利湖盆地沼泽的湿地养殖中观实验中估计水文条件对养分保留和植物丰富度的重要性

伊利湖西部盆地是北美劳伦森五大湖中最浅的，现在每年都受到有害藻华的困扰，原因是养分主要来自其盆地。2014 年，有毒蓝藻严重影响了水质，以至于托莱多市的供水被关闭，影响了数十万居民。一种新的农业土地管理方法“湿地养殖（=湿地 + 农业）”的目标是减少施肥需求，同时防止养分流入下游水生生态系统。在前“大黑沼泽”的西北边缘，俄亥俄州 Defiance 附近的农田上进行了湿养殖中观实验。^-1 )。附近的农用沟渠水被抽走，以提供每周给中观世界的水力负荷率。在两年期间，水力加载速率较高的湿地中观世界中，水中磷的净质量保留估计平均为 1.0 g P m ^-2，而估计的净氮质量保留最高（平均 22 g N·m ^-2) 显示在湿地中观中，具有 10 厘米的静水和更高的水力加载速率。我们的发现表明，水文条件，尤其是水位，直接和间接地促进养分保留，部分是通过湿地植被群落的快速反应。这项研究为扩大恢复前大黑沼泽的重要湿地养殖/湿地区域提供了有价值的信息，战略重点是减少从莫米河流域到伊利湖西部的养分负荷。