Identifying the Ecological and Management Implications of Mangrove Migration in the Northern Gulf of America

In the northern Gulf of America, mangrove forests have been expanding their northern range limits in parts of Texas, Louisiana, and north Florida since 1989. In response to warming winter temperatures, mangroves, which are dominant in warmer climates, are expected to continue migrating northward at the expense of salt marshes, which fare better in cooler climates. The ecological implications and timing of mangrove expansion is not well understood, and coastal wetland managers need information and tools that will enable them to identify and forecast the ecological impacts of this shift from salt marsh to mangrove-dominated coastal ecosystems.

To address this need, researchers will host workshops and leverage existing collaborations with scientists across the northern Gulf of America to develop products that are relevant to resource managers within this transition zone between mangrove forests and salt marshes. First, researchers will leverage a community-curated data network called the Mangrove Migration Network to examine temperature thresholds for damage and mortality for several mangrove species that are common to the region. The winter of 2017-2018 in particular, during which extreme winter temperatures were experienced in the northern Gulf of America, presents an outstanding opportunity to improve our ability to forecast the effects of changing winter temperature extremes on coastal wetlands. Researchers will integrate data from the Mangrove Migration Network to assess the vulnerability of coastal wetlands to changing winter temperature extremes. Second, three workshops will be held with managers throughout the region to identify issues related to mangrove restoration and management in coastal wetlands in Texas, Louisiana, and north Florida. The results of this effort will help federal and state land managers better understand what is happening on the lands they manage, and evaluate alternative management and restoration activities that involve migrating mangroves. Mangrove expansion is occurring on many Department of Interior lands, such as national wildlife refuge and national seashore lands. This work will support the conservation stewardship missions of both the U.S. Fish and Wildlife Service and National Park Service by providing science to inform management of lands along the Gulf of America.