Study: Mangroves in Florida expanding poleward
According to a study published in the Proceedings of the National Academy of Sciences (PNAS) journal, Mangrove trees, which are highly sensitive to cold, have expanded extremely on the pole ward side or on the Atlantic coast of Florida as the frequency of frosts has diminished.
Mangroves are restricted to the tropical areas as they cannot tolerate the extreme cold events that are so very typical of the temperate zone. Thus, the massive expansion of mangroves in the temperate zone of Florida during the last three decades is a proof of climate change’s role.
- Over 28 years, the Florida coast, from Miami northwards, gained more than 3,000 acres of Mangroves.
- The reason for this strange expansion/reduction in mangrove coverage boils down to extreme cold events — days colder than -4o C. The -4o C is the physiological temperature limit of mangrove survival.
Usefulness of Mangrove trees
- They form a biomass of trees that tolerate salt in tidal areas near freshwater estuaries on tropical coastlines.
- Support great biological diversity, including numerous species of crustaceans, fish, birds and molluscs.
- Both salt marshes and mangroves help contain flooding, store atmospheric carbon and contribute to the expansion of the land mass.
Note: At present, Mangrove forests face deforestation from carbon production, aquaculture and urbanization, and are threatened by drainage from sewers, while salt marshes are threatened by waste-water pollution and rising sea levels.