Surratt Donatto, Aumen Nicholas G
Everglades National Park, National Park Service, c/o A.R.M. Loxahatchee National Wildlife Refuge 10218 Lee Rd, Boynton Beach, FL, 33473, USA,
Environ Manage. 2014 Aug;54(2):223-39. doi: 10.1007/s00267-014-0288-9. Epub 2014 May 21.
Everglades restoration is dependent on constructed wetlands to treat agricultural phosphorus (P)-enriched runoff prior to delivery to the Everglades. Over the last 5 years, P concentrations delivered to the northern boundary of Everglades National Park (Park) have remained higher than the 8 μg L(-1)-target identified to be protective of flora and fauna. Historically, Everglades hydrology was driven by rainfall that would then sheetflow through the system. The system is now divided into a number of large impoundments. We use sodium-to-calcium ratios as a water source discriminator to assess the influence of management and environmental conditions to understand why P concentrations in Park inflows remain higher than that of the target. Runoff from Water Conservation Area 3A (Area 3A) and canal water from areas north of Area 3A are two major sources of water to the Park, and both have distinct Na:Ca ratios. The P concentrations of Park inflows have decreased since the 1980s, and from June 1994 through May 2000, concentrations were the lowest when Area 3A water depths were the deepest. Area 3A depths declined following this period and P concentrations subsequently increased. Further, some water sources for the Park are not treated and are impeding concentration reductions. Promoting sheetflow over channelized flow and treating untreated water sources can work in conjunction with constructed wetlands to further reduce nutrient loading to the sensitive Everglades ecosystem.
大沼泽地的恢复依赖于人工湿地，以便在将富含农业磷（P）的径流输送到大沼泽地之前对其进行处理。在过去5年中，输送到大沼泽地国家公园（公园）北部边界的磷浓度一直高于确定的保护动植物的8μg L(-1)目标值。从历史上看，大沼泽地的水文状况受降雨驱动，降雨随后会以坡面流的形式流经整个系统。现在该系统被划分为多个大型蓄水池。我们使用钠钙比作为水源判别指标，以评估管理和环境条件的影响，从而了解公园入流中的磷浓度为何仍高于目标值。来自3A水资源保护区（3A区）的径流和3A区以北地区的运河水是公园的两大主要水源，且二者具有不同的钠钙比。自20世纪80年代以来，公园入流中的磷浓度有所下降，在1994年6月至2000年5月期间，当3A区水深最深时，磷浓度最低。在此之后，3A区水深下降，磷浓度随后上升。此外，公园的一些水源未经处理，这阻碍了磷浓度的降低。促进坡面流而非渠道化水流，并处理未处理的水源，可与人工湿地协同作用，进一步减少对敏感的大沼泽地生态系统的养分负荷。
