Fort Matanzas's First Vegetation Survey: 82 Species, a New Wildflower, No Red Bay

In 2004, red bay was one of the main understory trees at Fort Matanzas National Monument in Florida. When botanists set up the park's first long-term vegetation plots in June 2019, they did not find a single living one. Laurel wilt, a tree disease detected in St. Johns County in 2006, may be why. The survey also turned up eight plants never recorded in the park before, and a wildflower so newly recognized that its conservation status is unknown.

The nine vegetation plots established in June 2019. Credit: National Park Service.

The park and the method

Fort Matanzas covers about 121 hectares (298 acres) on the Atlantic coast, 14 miles south of St. Augustine. It is split by the Matanzas River: the eastern parcel on the southern tip of Anastasia Island, the western on the northern third of Rattlesnake Island. Beaches give way to foredunes, then to stabilized dunes and backdunes with sandy herb-covered flats, maritime scrub and forest.

The Park Service's Southeast Coast Network uses a peer-reviewed protocol, modeled on the Carolina Vegetation Survey, to track vegetation over time. In permanent plots placed at random within the main habitat types, botanists record every native and non-native plant species and its abundance, the size, density and health of woody stems, forest-floor fuels, disturbances such as insect pests and disease, and the physical setting — landform, soil nutrients, canopy cover and height. The 2019 data, from nine plots in upland forests and shrublands and open upland grasslands, are the park's baseline.

What they found

• 82 plant species, including 8 not detected in earlier surveys. Plots held 10 to 32 species each; grasses, sedges and herbs were most diverse in the open uplands.
• No state-tracked rare species — but one plot held the newly described Florida blue curls (Trichostema species 2), a perennial long lumped with common or scrub blue curls until molecular studies suggested it is distinct.
• Few invaders. Non-native plants appeared in three of the nine plots, including one invasive Brazilian pepper.
• Palms and cedars. Forests and shrublands had a canopy of cabbage palmetto and southern/eastern red cedar over a sapling layer of yaupon.
• Commercially harvested plants. Three species the Florida Department of Agriculture and Consumer Services lists as commercially exploited grew in the plots: cinnamon fern, saw palmetto and coontie.

Southeast Coast Network botanist M. Forbes Boyle searches for new plants in a species-rich backdune at the southern end of Anastasia Island. Credit: Elizabeth Rico, National Park Service.

Shaped by wind and water

Soil pH ranged from 5.3 (acidic) to 8.1 (slightly alkaline), across the ridges and swales of young and old dunes. Wind, tides and waves have always sculpted the park's plant life. Disturbances seen in other network parks — heavy browsing, old plowing, fire effects, altered water flow — were not found in these plots.

The plots were scheduled to be resampled in summer 2023. Tracking them is part of the Park Service's Vital Signs Monitoring program, begun in 1999 to measure long-term trends in the ecosystems of more than 270 park units.

Sources

Based on "Terrestrial Vegetation Monitoring 2019 Data Summary for Fort Matanzas National Monument," National Park Service Southeast Coast Network; a work of the United States government in the public domain. The full report is on the NPS DataStore.