Northward Expansion of Mangroves: Drivers, Ecological Impacts, and Proposed Research

Coastal wetland habitats, including mangroves and salt marshes, provide invaluable ecological and economic benefits to shorelines. However, climate changes, such as increases in temperature, the frequency and intensity of tropical storms, and sea level rise, pose major threats to these habitats. This study synthesizes findings from peer-reviewed studies published between 2009 and 2024 regarding mangrove migration and coastal wetland dynamics across the Gulf of Mexico and the southern Atlantic coast of North America. Literature focused on the northward and inland expansion of mangrove forests into salt marsh habitats using remote sensing data, as well as identifying environmental cues that drive these shifts. Reviewed studies showed evidence that mangrove expansion and poleward migration correlated with a reduction in hard freezes and propagule dispersal driven by tropical storms. Additionally, mangrove migration has begun encroaching on salt-marsh habitats, where mangroves are more likely to outcompete salt marshes in the event of rising sea levels. However, most studies lacked long-term climate records or high-resolution remote sensing data, limiting their ability to assess historical changes or predict future trends. To address these gaps, my research proposes using high-resolution remote sensing data and long-term climate data to confirm mangrove expansion and salt marsh conversion and evaluate the link to regional weather trends along the eastern coast of Florida. Loss of salt marsh habitat to mangroves impacts the functionality and resilience of coastal habitats in terms of fishery nurseries, carbon storage, biodiversity, and coastal erosion. Understanding the driving factors and implications of mangrove migration and expansion is crucial for conserving coastal wetlands and developing proper management and adaptation strategies under climate change.