As mangrove trees lose ground to deforestation and urban sprawl, one development seems to be giving them a boost: climate change. Fewer winter cold snaps have enabled them to conquer new territory around their northern Florida boundary, according to a study of 28 years of satellite data from the Smithsonian Environmental Research Center and the University of Maryland published Dec. 30 in the Proceedings of the National Academy of Sciences.
An estimated 35 percent of the world's mangroves have been destroyed since 1980, according to previous research, outstripping tropical rainforests and coral reefs. They are also some of the planet's most valuable ecosystems. Mangroves protect coastal cities from floods and hurricanes. Their above-ground roots shelter many commercially valuable fisheries, including blue crabs, shrimp and lobsters. And they are phenomenal at burying carbon. The soils of coastal ecosystems like mangroves can store carbon at a rate 50 times higher than tropical rainforests. Scientists have estimated their total ecosystem services value more than $1.6 trillion a yearmaking the expansion a possible blessing.
"Some people may say this is a good thing, because of the tremendous threats that mangroves face," said the study's lead author, Kyle Cavanaugh, a postdoctoral research fellow at the Smithsonian Environmental Research Center in Edgewater, Md. "But this is not taking place in a vacuum. The mangroves are replacing salt marshes, which have important ecosystem functions and food webs of their own."
The study tracked the expansion of mangroves in Florida using 28 years of satellite imagery. The northern edge of their range sits at 30 degrees north latitude, just north of St. Augustine. The research team analyzed satellite data from 1984 to 2011 showing where Florida's mangrove territory shrank or grew, from St. Augustine in the north to Miami's Biscayne Bay in the south. Then they compared that data with temperature
|Contact: Kristen Minogue|