Sea level rise may reduce mangrove carbon storage

Rising sea levels threaten to transform mangrove forests from crucial carbon storage systems into sources of atmospheric carbon, according to new research. A study led by the University of Exeter, in collaboration with partners in Colombia and the United States, indicates that while some parts of these coastal ecosystems may initially store more carbon, the overall capacity of entire mangrove forests is likely to decline significantly over the next century.

Mangroves are salt-tolerant trees and shrubs that cover less than one percent of the Earth’s surface but store roughly 15 percent of all carbon held in ocean ecosystems, primarily within their dense, waterlogged soils. They are also vital for protecting coastlines from storms and supporting marine life and coastal communities.

The research, published in the journal Earth’s Future, employed a novel computer model that integrated water flow, sediment transport, mangrove growth and mortality, and carbon dynamics. This approach allowed scientists to assess the landscape-scale response of mangrove forests to sea-level rise, moving beyond localized field observations.

The findings reveal a complex picture. While increased flooding...