Climate change may be helping mangrove trees spread northwards.
Warmer winters have allowed the trees to move into the colder north around the Florida boundary, a Smithsonian news release reported.
The researchers looked at 28 years' worth of satellite data to make their findings.
The mangroves have been battling humans, who have wiped out 35 percent of the trees, since the 1980s.
The trees are some of the world's "most valuable ecosystems" and even protect coastal residential areas from natural disaster threats. Their above-the-ground roots help protect a number of aquatic populations like "blue crabs, shrimp and lobsters."
The trees also help battle climate change by "burying" carbon; they are able to absorb levels of carbon 50 times higher than tropical rainforests and provide the equivalent of $1.6 trillion a year in "environmental services."
"Some people may say this is a good thing, because of the tremendous threats that mangroves face," the study's lead author, Kyle Cavanaugh, a postdoctoral research fellow at the Smithsonian Environmental Research Center in Edgewater, Md, said. "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 team found the trees have gained around 3,000 acres of coverage since the year 1987. The researchers believe the spread is not related to warmer temperatures, but rather the lack of "cold snaps," which are classified as temperatures below 28.4 degrees Fahrenheit. These cold snaps are becoming less frequent as the years go on. The first five years of the study saw 1.4 more cold snap days than the last five years.
"This is what we would expect to see happening with climate change, one ecosystem replacing another," Dan Gruner, a co-author from the University of Maryland at College Park said. "But at this point we don't have enough information to predict what the long-term consequences will be."
