Pythons, lionfish and now willow invade Florida's waterways

University of Central Florida: Foreign invaders such as pythons and lionfish are not the only threats to Florida’s natural habitat. The native Carolina Willow is also starting to strangle portions of the St. Johns River.

Biologists at the University of Central Florida recently completed a study that shows this slender tree once used by Native Americans for medicinal purposes, may  be thriving because of water-management projects initiated in the 1950s. Canals were built to control  runoff and provide water for agriculture. The unintended consequence — stable water levels — allowed Carolina Willow to spread and thrive.

They now cover thousands of acres. Willows form impenetrable thickets that prevent boating and eliminate duck habitat. Willow thickets also use tremendous amounts of water, leaving less available for wildlife and people. The findings were published today in Restoration Ecology,  the peer-reviewed journal of the Society for Ecological Restoration. The St. Johns Water Management District funded the study.

While the trees previously were kept in check by natural annual flooding, they can now be found thriving in wetlands, swamps and marshes. Some trees grow as tall as 35 feet. The leaves of the tree contain salicin, which is the compound behind the pain-relieving effect of salicylic acid found in aspirin.

UCF professors Pedro F. Quintana-Ascencio and John Fauth worked with Kimberli Ponzio and Dianne Hall, scientists from the St. Johns River Water Management District, to run experiments that found ways to control the willow, which is taking over marshes in the upper St. Johns River basin....

St. John's River near Orange City, Florida, shot by Mwanner, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license