Resilience to Hurricanes is High in Mangrove Blue Carbon Forests

Background

While many anthropogenic forces threaten the survival of mangrove forests, tropical storms are the most significant non-anthropogenic sources of disturbance. Since mangroves are important carbon sinks, it is important to understand the impacts of tropical storms on mangrove forest structure, function, and carbon stock recovery.

Goals and Methods

This study examines the recovery patterns of two mangrove sites in Florida, United States, after two separate hurricane events (Hurricane Wilma in 2005 and Hurricane Irma in 2017). The authors assess how changes in ecosystem structure and canopy biomass interact and affect ecosystem recovery using leaf area index (LAI), collected from remote sensing satellites, and carbon cycling dynamics, measured by net carbon dioxide exchange (NEE), collected from onsite wind, gas, and radiation sensors. Data analysis consisted of various mathematical models and statistical tests.

Conclusions and Takeaways

The mangrove sites recovered all carbon lost within four years after disturbance. Landscape-scale rates of enhanced carbon capture offset smaller sections of mangroves still recovering after four years. The taller, more mature mangrove site experienced steeper declines in LAI and greater effects due to maximum assimilation of carbon dioxide (Amax) and ecosystem respiration (Reco) due to downed woody debris from the storm, causing an increase in the time to return to pre-disturbance NEE. However, storm surges deposited sediments rich in phosphorus onto the mangroves, which enhanced Amax and Reco, and stimulated rapid forest recovery and soil biomass accumulation.