Based on the National Park Service Southeast Coast Network's 2020 data summary for terrestrial vegetation monitoring.
Why monitor plants
Plant communities change with the environment and with natural and human disturbance. In the southeastern Coastal Plain, their diversity supports ecological services, gives wildlife habitat and food, and is often what draws people to appreciate the outdoors. Tracking trends and stresses in vegetation helps the Southeast Coast Network understand the ecological health of its parks and guide management that sustains them.
Methods
The network uses a peer-reviewed protocol like those of other eastern NPS Inventory and Monitoring networks, modeled on the Carolina Vegetation Survey. Permanent, randomly placed plots in the parks' main habitat types (those covering more than 30% of a park, and others when time allows) record:
- richness and abundance of all native and non-native vascular plants;
- basal area, density and health of all trees;
- density of forest-floor fuels;
- community disturbances, including insect pests and disease;
- physical conditions such as landform, soil nutrients, and canopy cover and height.
The park
Fort Frederica National Monument is on St. Simons Island in Glynn County, Georgia. Its 123 hectares (305 acres) are split between the main unit, on a bluff over the Mackay (Frederica) River with the headquarters, visitor center and fort, and the Bloody Marsh Battle Site. The colonial townsite around the fort is kept as a mowed field.
The park's upland forests mix live oak with other hardwoods, or are pine-dominated successional forests on sites that were once hardwood. Salt marsh of smooth cordgrass and black needlerush fills the lowest ground along the river. The protocol was used here for the first time in 2020, with five plots in Maritime Upland Forest and Shrubland habitat, setting a baseline.
Vegetation plots established in summer 2020. Image from the National Park Service's page.
Conditions
Like Georgia's other barrier islands, Fort Frederica's vegetation is shaped by tides, ocean winds and storms, and river sediment. Storms and salty conditions govern the mix of marsh and forest, and soils, water and disturbances such as fire and storms drive plant diversity. Most plot soils were acidic, and windthrow turned up in all five plots.
What grows there
- 91 plant species were found across the plots, including 19 never recorded in earlier surveys of the park and one rare species tracked by the Georgia Department of Natural Resources.
- Each plot held 27 to 49 species, dominated by trees and herbaceous plants.
- The canopy was typically Darlington oak and loblolly pine.
- Non-native species were in all but one of the five plots. Two invasive species listed by the Georgia Exotic Pest Plant Council, camphortree and Chinese tallow, appeared in four plots.
Average species richness (± standard deviation) by growth form. Image from the National Park Service's page.
Mean occurrence of native and non-native species. Image from the National Park Service's page.
Young forest
Frequent windthrow and past land use such as farming and timber management have left the park with little older maritime forest. Most of the canopy is made up of species typical of younger maritime forest, such as Darlington oak and pines. Future monitoring will show whether species of mature maritime forest, such as live oak, become more common. The plots were due to be resampled in summer 2024.
Oak and pine maritime forest of varying ages at Fort Frederica. NPS photo/M. Forbes Boyle.
Vital Signs Monitoring
The National Park Service began its long-term Vital Signs Monitoring program in 1999 to help more than 270 park units track their highest-priority measures of resource condition: the status and trends of their ecosystems, early warning of problems, data for legal mandates, and measures of management progress. The Southeast Coast Network covers eighteen administrative areas with twenty park units in North Carolina, South Carolina, Georgia, Alabama and Florida, spanning more than 184,000 acres of federal land.
Sources
- National Park Service, Southeast Coast Network, "Terrestrial Vegetation Monitoring 2020 Data Summary for Fort Frederica National Monument": https://www.nps.gov/articles/000/secn-vegetation-monitoring-fofr-2020.htm
- Full report: https://irma.nps.gov/DataStore/Reference/Profile/2294844
Licence: CC0 1.0 (public domain) · Adapted from www.nps.gov
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