The degradation and loss of ecologically important wetlands has been a topical issue in the Great Lakes region, where 60–80% of the coastal wetlands have been lost since the 1800s. The present modeling study aims to guide the restoration efforts in Cootes Paradise marsh, one of the most degraded shallow wetlands in Southern Ontario. We use a process‐based eutrophication model designed to reproduce the biotic competition among multiple phytoplankton and macrophyte functional groups. Our primary focus is to offer guidelines for wetland restoration by characterizing the ecophysiological processes of the autotrophic assemblage, such as the nutrient uptake from the water column and/or the sediment pore waters, the relative ability to harvest light and fuel photosynthesis, and temperature control of the algal/macrophyte growth and basal metabolism. We predict that the additional reduction of external phosphorus loading in Cootes Paradise could induce an abrupt, non‐linear shift from the current turbid phytoplankton‐dominated state to a desirable clear macrophyte‐dominated state. The emergence of this critical (or tipping) point, where the shift to another ecological state may occur, can be accelerated by the presence of a thriving macrophyte community with an enhanced ability to sequester phosphorus. However, it may also be delayed by the presence of a suite of biogeochemical mechanisms (often referred to as “feedback loops”), such as the remobilization of legacy P due to sediment diagenetic processes, wind resuspension, bioturbation, hydraulic loading from local tributaries, water‐level fluctuations, and the leachable P pool of dead plant material that can be returned into the water column through senescence. Our study identifies the restoration actions required to minimize the likelihood of prolonged hysteresis and to facilitate a shift to a desirable ecological state in the foreseeable future. The areal expansion of aquatic vegetation will not only lead to the establishment of a thriving meadow and emergent vegetation community, but may also pave the way for submerged macrophytes through a suite of synergistic mechanisms. Additional point‐source loading reductions will facilitate the transition to an alternative stable clear macrophyte‐dominated state, but could also consolidate the future resilience of the marsh.

中文翻译：

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大湖湿地的富营养化管理：研究替代生态状态的存在

具有重要生态意义的湿地的退化和丧失是大湖地区的一个热门话题，自1800年代以来，那里60％至80％的沿海湿地已经丧失。本建模研究旨在指导库特斯天堂沼泽（Cootes Paradise Marsh）的恢复工作，该沼泽是安大略省南部退化最严重的浅湿地之一。我们使用基于过程的富营养化模型，旨在重现多个浮游植物和大型植物功能组之间的生物竞争。我们的主要重点是通过描述自养组合的生态生理过程（例如从水柱和/或沉积物孔隙水吸收养分，收集光和燃料光合作用的相对能力以及温度控制）来为湿地恢复提供指导/藻类生长和基础代谢的变化。我们预测，库特斯天堂中外部磷含量的进一步降低可能会导致从当前浑浊的浮游植物为主的状态突然向非线性的转变，转变为理想的清晰的大型植物为主的状态。兴旺的大型植物群落具有增强的螯合磷的能力，可以加速这一临界点（或临界点）的出现，在该临界点处可能发生向另一种生态状态的转变。但是，也可能由于存在一套生物地球化学机制（通常称为“反馈回路”）（例如遗留物的转移）而延迟 兴旺的大型植物群落具有增强的螯合磷的能力，可以加速这一临界点（或临界点）的出现，在该临界点处可能发生向另一种生态状态的转变。但是，也可能由于存在一套生物地球化学机制（通常称为“反馈回路”）（例如遗留物的转移）而延迟 兴旺的大型植物群落具有增强的螯合磷的能力，可以加速这一临界点（或临界点）的出现，在该临界点处可能发生向另一种生态状态的转变。但是，也可能由于存在一系列生物地球化学机制（通常称为“反馈回路”）（例如遗留物的转移）而延迟P由于沉积物成岩作用过程，风再悬浮，生物扰动，从本地支流，水位的波动，可浸提的水力负荷P可以通过衰老返回到水柱中的死植物材料库。我们的研究确定了在可预见的将来需要采取的修复措施，以最大程度地减少滞后现象的发生并促进向理想的生态状态的转变。水生植物的面积扩展不仅将导致兴旺的草地和新兴的植被群落的建立，而且还可能通过一套协同机制为淹没的大型植物铺平道路。进一步减少点源负荷将有助于过渡到另一种稳定的，清晰的大型植物为主的状态，但也可以巩固沼泽的未来复原力。