Florida's Mangroves Head North

The world's mangroves—rich tropical ecosystems made up of trees and shrubs—tend to be shrinking in dramatic fashion, but Florida's mangroves seem to have bucked the trend, the Smithsonian reports. In fact, they're expanding to the north along the Atlantic coast. The state's mangroves typically haven't grown beyond a latitude of approximately 30 degrees North. Between 1984 and 2011, however, the forests became more common near that latitude, adding some 3,000 acres of coverage, according to a newly published study. Between Cape Canaveral and St. Augustine, for example, mangrove coverage has doubled, the Miami Herald reports.

Scientists have tied the expansion to the fact that the region has seen fewer days with temperatures below 25 degrees Fahrenheit. (The mangroves can't bounce back in the spring if it gets too cold.) It may all sound like good news for the mangroves, but the outcome for the local environment as a whole isn't clear. "The expansion isn’t happening in a vacuum," notes the study's lead author. "The mangroves are expanding into and invading salt marsh, which also provides an important habitat for a variety of species." (Humans like Florida's warm weather, too, and the state is expected to pass New York soon in population.)