As Florida becomes increasingly urbanized, more than half the state’s stormwater ponds appear in two metropolitan areas -- Orlando and Tampa Bay, new research from the University of Florida shows.
In their first attempt to quantify stormwater ponds, researchers with the UF Institute of Food and Agricultural Sciences found about 76,000 such ponds statewide. Many master-planned communities, especially in Florida, rely on stormwater ponds for flood control and water treatment. But the ponds also can be homes to many invasive plant species, which are costly to control.
Suspecting invasive plants can thrive in stormwater ponds, a group of UF/IFAS scientists reviewed maps of Florida to find the ponds. They also examined the number and types of invasive plants in about 30 such ponds in Gainesville, Florida, chosen for its proximity to UF and how its ponds are managed.
Their study showed about 41,100 stormwater ponds in Central Florida, a region that scientists broadly defined as the Interstate 4 corridor urban regions of Tampa Bay and Orlando. By contrast, researchers found about 6,300 such ponds in the Panhandle, a more rural area.
Researchers found about 70 percent of the invasive plant species in the Gainesville ponds were horticultural plants commonly used for urban and residential landscaping. People introduce invasive plants through their landscape choices, said Basil Iannone, a UF/IFAS assistant professor of landscape ecology.
“These popular landscaping plant species eventually reproduce, and their offspring move to new habitats, which include stormwater ponds,” said Iannone, a faculty member in the UF/IFAS School of Forest Resources and Conservation and the corresponding author for the study. “We are installing thousands of these engineered ecosystems that can have negative ecological impacts, including facilitating the spread of invasive plants. On the other hand, we can likely manage them better to limit or even eliminate these impacts. We just need to figure out how to do that.”
Added study co-author AJ Reisinger: “What our work shows is that stormwater ponds have the potential to facilitate invasive plants by providing them a habitat to colonize in the middle of urban landscapes.”
Invasive plants, especially those that impact waterways, cost Floridians about $45 million a year to control, according to UF/IFAS research. They also reduce native plant abundance in natural and urban areas.
Invasive plants can spread from stormwater ponds and wreak havoc on natural ecosystems, said Reisinger, a UF/IFAS assistant professor of soil and water sciences. Examples of “natural” areas could be wetlands or forests. Urban areas could be parks, lawns and urban forests, he said.
“Stormwater ponds are everywhere, and they will continue to be an important component of urban development,” Reisinger said. “They are needed to manage stormwater runoff and reduce downstream flooding. However, our work shows that they can have the unintended consequences of being a habitat for a variety of different invasive species.”