Potential Effects of Climate Change on Forested Wetlands in the Lower Mississippi Valley.

The Lower Mississippi Valley (LMV) is the Nation's largest floodplain and the forest and wetland ecosystems of the LMV provide critically important ecosystem services. Climate is a large-scale agent of change controlling dominant drivers (e.g., hydrologic regimes and land cover) of ecosystem structure, processes, and services. The effects of predicted climate change on hydrology and land cover and the cascading impacts on critical ecosystem services in the LMV are largely unknown. This is a significant gap in our knowledge base directly affecting resource management, conservation, and ecosystem restoration programs of federal, state, and local governments.  The resilience and sustainability of the forest and wetland ecosystems in the LMV are directly connected to the hydrologic regime. We will use current research and existing literature to evaluate the impacts of the two predicted future climates in the LMV (higher temperatures + higher precipitation or higher temperatures + lower precipitation) on wetland ecosystems. For example, increasing hydroperiod with greater precipitation can reduce CO₂ emissions and increase soil carbon sequestration. However, current research in forested wetlands confirms that concurrent increases in CH₄ emissions will offset the larger soil carbon storage resulting in a net increase in global warming potential. Interactive effects like these are important since large areas of the LMV are being reforested to sequester carbon and provide concurrent ecological benefits. Ecosystem services resulting from these efforts are being managed for and predicted under current climatic conditions, which may not be valid.