by Craig Mallison and Siobhan Gorham
Blue Spring State Park in Volusia County has been open to the public as a state park since 1972 and includes Blue Spring, the largest single spring on the St. Johns River system. In addition to the spring, the park encompasses a spring run and a lagoon with an adjacent marsh. Due to extended drought, infrequent fire, and fluctuating water levels, the marsh habitat has degraded over time with advancement of woody vegetation including willow, red maple, and buttonbush. The Aquatic Habitat Restoration and Enhancement Section (AHRE), within FWC’s Division of Habitat and Species Conservation, teamed with the Florida Department of Natural Resources to initiate a project to control the encroaching woody plants and restore herbaceous marsh habitat. They contacted the Freshwater Plants Research project to evaluate the effectiveness of herbicide treatments and prescribed fire in restoring quality habitat in the marsh.
We will compare composition of woody vegetation and herbaceous marsh in treated areas and non-treated (control) areas over time. Pre-treatment sampling and aerial herbicide treatments were completed in October 2014. We used aerial photography, acquired by AHRE, along with field survey data to map the plant communities within the entire study area. We established three one-acre sampling plots within each treatment group. Initial results documented 80 percent coverage of woody vegetation and 20 percent coverage of herbaceous marsh within treated and control plots. Sampling will be completed annually for three years to evaluate changes in community composition. The management objectives of the herbicide treatment are to reduce woody vegetation by 70 percent and to increase herbaceous marsh by 50 percent. This would establish plant communities that can be maintained with a prescribed fire regime to sustain quality freshwater marsh habitat into the future.