Mississippi River Flood of 2008: Flood-Pulsed Experiments of Coastal Ecosystem Dynamics

2008 年密西西比河洪水：沿海生态系统动力学的洪水脉冲实验

• 批准号: 0833225
• 负责人: John White
• 金额: $ 9.99万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-15 至 2009-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0833225&HistoricalAwards=false
• 关键词: Mississippi; River; Flood; 2008; Pulsed

This SGER project will examine how river flood pulsing controls freshwater residence time in coastal wetland basins of Louisiana, and how this control regulates biogeochemical processing of nitrogen (N). The central hypothesis is that the pulsed event of river floods will decrease N retention and removal by wetlands (via denitrification) by drastically decreasing water residence times in entire wetland basins. This, in turn, will lead to increased N loading to the Gulf of Mexico, where anthropogenic N loading has long been implicated in coastal hypoxia and the Northern Gulf Dead Zone. It will take advantage of The Mississippi River flood of 2008, which will be one of the largest pulses of freshwater for wetlands in coastal Louisiana in almost a century. This study will use managed river diversions into the study basins to examine this relationship between freshwater inputs and nitrogen retention.This research will provide ecosystem managers, who manage valuable, large wetland systems like the Mississippi River Delta and the Florida Everglades, with critical water quality information. One management goal is to prevent excess N from reaching the coastal ocean where many economically important fisheries are located and where excess N causes toxic algal blooms, low dissolved oxygen, and massive fish kills. This experiment will also provide important data on how well coastal wetlands respond to very large pulses of freshwater.

这个SGER项目将研究路易斯安那州沿海湿地盆地的河流脉动如何控制淡水停留时间，以及该控制如何调节氮的生物地球化学加工（N）。 中心假设是，河流洪水的脉冲事件将通过大大减少整个湿地盆地的水位时间，从而减少湿地（通过反硝化）的氮保留率和去除。 反过来，这将导致墨西哥湾的n负载增加，在那里，人为n负载长期以来与沿海缺氧和北部海湾死区有关。 它将利用2008年的密西西比河洪水，这将是近一个世纪以来路易斯安那州沿海湿地的最大淡水豆类之一。这项研究将利用托管河流转移到研究盆地，以检查淡水投入和氮保留之间的这种关系。这项研究将为生态系统经理提供，他们管理有价值的大型湿地系统，例如密西西比河三角洲和佛罗里达州的Everglades，并提供关键水质信息。 一个管理目标是防止多余的n到达许多经济重要的渔业所在的沿海海洋，而多余的n导致有毒的藻类开花，低溶解的氧气和大量的鱼类杀死。 该实验还将提供有关沿海湿地对淡水非常大的脉冲的反应良好的重要数据。