Nestled among the business developments and suburbs of Florida’s Space Coast and hidden within dense patches of hickory and oak trees on dry, nutrient poor sands, you can find a spindly and discreet minty herb popping up. Its delicate purple flowers and fragrant fleshy leaves persist even in this harsh environment surrounded by vegetation bigger and better at competing for resources. Restricted to a 13-mile range in the northeastern part of Brevard County atop the Atlantic Coastal Ridge, this plant — known as the Titusville Balm (Dicerandra thinicola) — is one of the rarer plants in the state of Florida, and in the world. But scientists studying this species are hopeful that it will endure, given a little encourage-mint from fire.
Since 2001, staff and interns from the Plant Ecology Program at Archbold Biological Station have travelled to the coast to study the Titusville Balm, along with Suzanne Kennedy, President of the environmental monitoring and consulting company FloraVista, Inc. While most populations of this state-endangered species are found on private land, the largest population occurs on public land at the city of Titusville’s Wellfield, a property serving as a primary aquifer recharge area. “However, such land may not offer permanent conservation protection and is not managed explicitly for endangered plants and animals,” explains Plant Ecology Program Director Dr. Eric Menges. The only protected and managed population of Titusville Balm was introduced by Archbold and Kennedy in 2002 onto the Dicerandra Scrub Sanctuary adjacent to the Titusville Wellfield, owned by Brevard County’s Environmentally Endangered Lands Program.
“We collect data on seedling recruitment, seedling and adult survival, plant size, and reproductive output annually at the populations persisting on the Titusville Wellfield and introduced to the Dicerandra Scrub Sanctuary,” says Research Assistant Stephanie Koontz, who led the field crew in their 18th year of data collection earlier this month. “We now have data on nearly 9,000 individual plants, allowing us to perform interesting analyses that may inform management decisions.”
The research team is particularly interested in understanding the species’ response to prescribed burning. “Individuals are killed by fire, so the population relies on existing dormant seeds buried in the soil to recover,” says Dr. Menges. “After fire, the data indicates increased seedling recruitment and health, with individuals producing an abundance of branches and flowering stems. These traits are consistent with fire effects on the two Florida mint species we study in Highlands County, the Garrett’s Mint (Dicerandra christmanii) and Scrub Balm (Dicerandra frutescens).” Koontz adds, “We also observe this in the field. In our long-unburned and overgrown study sites, we find that Titusville Balm persists at much lower densities, there are fewer seedlings found and individuals do not appear to be as healthy. Many scrub endemic species like this require periodic fire to suppress tree and shrub overgrowth.”
Luckily, land managers with the Brevard County Environmentally Endangered Lands Program pay attention to what these scientists suggests and have been focused on getting the Dicerandra Scrub Sanctuary burned. It finally happened this fall on October 31, just before the Archbold crew arrived at the site for their annual data collection. “Our study sites in the area may look decimated now,” notes Research Assistant Katherine Charton, “but I know that in a year we’ll come back and find hundreds of new individuals beginning to grow in this same place. We look forward to the additional opportunity to monitor this population post-fire.”
Archbold was joined in the field this year by a number of collaborators and parties interested in learning more about the monitoring process. “The project would not be possible without the continued collaboration of Suzanne Kennedy, who has been involved with this project from its conception and again joined us in the field for this year’s annual data collection,” says Dr. Menges. Also adding to the crew were land managers and volunteers from the Brevard County Environmentally Endangered Lands Program and staff from University of Central Florida’s Landscape and Natural Resources Program.
Written by Katherine Charton