RAPID: Short term effects of initial flood disturbance on restoration projects

季节性洪水维持了泛滥平原河流生态系统的生物生产力和多样性，但罕见的大洪水对这些生态系统的影响却鲜为人知。在河流生态系统已经开发和正在恢复泛滥平原的地方，了解这种类型洪水的影响至关重要，因为在使用恢复的泛滥平原来维持本地物种和自然功能与利用它们来减少对生命和财产的威胁之间可能存在权衡。2013年4月伊利诺伊河创纪录的洪水淹没了自然保护协会进行的两个泛滥平原恢复项目；这两个项目在2013年之前都没有获得河水。有两种截然不同的洪水情况：1)在Merwin工地，堤坝决口，导致河水突然持续涌入。这种洪水模式代表了故意决口以减少洪峰期间发生的事情；2)在埃米昆，堤坝坚固，但河水流入现场，为该地区接种营养物质和生物。埃米孔的模式代表了季节性洪水或设法优化物种恢复和自然功能的洪水。在这两个地点，将在营养物质和沉积物浓度、沉积物反硝化以及藻类生物量、细菌群落和浮游动物产量的变化方面测量快速反应。植被、鱼类和水鸟的长期反应将通过将2013年洪灾后的数据与现有的长期数据集进行比较来确定。该项目的结果，包括短期和长期的数据集和分析，将有助于泛滥平原的管理人员和决策者。该项目将支持三名研究生的毕业论文研究，并为三名河流生态学本科生提供研究经验。将通过出版物以及为学生和访问团体举办的实地讲座/讲习班，通过在三个河流野外站设立的方案，与公众、政府和私营组织分享所学到的经验教训。

Seasonal floods maintain the biological productivity and diversity of floodplain-river ecosystems, but the effect of infrequent, great floods on these ecosystems are less well known. Knowing the effect of this type of flood is critical where river ecosystems have been developed and where floodplains are now being restored because there are likely trade-offs between using restored floodplains to maintain native species and natural functions and using them to reduce threats to lives and property. The record flood of April 2013 on the Illinois River flooded two floodplain restoration projects undertaken by The Nature Conservancy; neither project had received river water prior to 2013. There were two contrasting flood regimes: 1) at the Merwin site, the levee breached resulting in a sudden and sustained influx of river water. This flood pattern typifies what happens during intentional breaching to reduce a flood crest; 2) at Emiquon, the levee held but river water flowed into the site inoculating the area with nutrients and organisms. The pattern at Emiquon typifies a seasonal flood or a flood managed to optimize species recovery and natural functions. At both sites, rapid responses will be measured in nutrient and sediment concentrations, sediment denitrification, and change in algal biomass, bacterial communities and zooplankton production. Longer-term responses of vegetation, fish, and water birds will be determined by comparing post flood 2013 data to existing long-term data sets. Results from this project, including both short and long-term data sets and analyses, will assist floodplain managers and policymakers. This project will support the dissertation research of three graduate students and provide research experiences for three undergraduate students in river ecology. Lessons learned will be shared with the public and government and private organizations through publications and field-based lectures/workshops for students and visiting groups through established programs at three river field stations.