Last updated: May 21, 2024
Article
Terrestrial Vegetation Monitoring 2019 Data Summary for Fort Pulaski National Monument
Overview
Vegetation communities are dynamic entities whose species composition, abundance, distribution, and structure are influenced by environmentalfactors and effects from natural and anthropogenic disturbances. The diversity of plants within the southeastern Coastal Plain contributes to a range of ecological services, provides habitat and resources to an array of wildlife, and functions as nature’s backdrop—usually the primary visual cue pulling us toward an appreciation of the outdoors. Determining trends in vegetation communities over time and identifying plant stressors is vital to understanding the ecological health of terrestrial ecosystems within Southeast Coast Network (SECN) parks. Collectively, this information can be used to guide management actions that sustain park’s ecological integrity and support plant conservation across a diversity of spatial scales for generations to come.
Methods
The Southeast Coast Network collects long-term data on terrestrial vegetation within its parks using a peer-reviewed protocol similar to other NPS Inventory and Monitoring networks in the eastern U.S. and is modeled after the approach used to describe natural vegetation in the Southeast developed by the Carolina Vegetation Survey. Bounded and monumented plots (20 × 20 meters [65.6 × 65.6 feet]) are used as the sample unit to determine a site’s (1) vascular plant richness and abundance (cover and frequency) for all native and non-native species; (2) woody stem abundance (basal area and density) and health for all native and non-native species; (3) density of forest floor fuels (along transects overlaying the vegetation plot); (4) community level disturbance events, including presence of insect pests and disease; and (5) abiotic condition (e.g., landform shape, soil nutrients, canopy coverage and height). Plots are randomly located across broadly defined habitat types within SECN parks. Our sampling effort focuses on dominant (> 30% coverage) habitat types within these parks, but when time and resources allow, the sampling effort is increased to include less dominant types. The 2019 Terrestrial Vegetation Monitoring Protocol provides detailed descriptions of field and data processing techniques used by the Southeast Coast Network.
Study Area
Fort Pulaski National Monument (FOPU) is located east of Savannah, Georgia along the Savannah River, a few miles west of the river’s junction with the Atlantic Ocean. The 2,276-hectare (5,623-acre) park is located on two islands greatly affected by human intervention over the past 300 years—Cockspur and McQueen’s. Cockspur Island, which includes the the fort, was selected as an early American defensive position in the 18th century and the construction of the fort began in the early 19th century. During this time, a vast network of drainage canals and dikes were installed on the island surrounding the fort. Much of the vegetation was removed during the Civil War-era in order to maintain visibility. The environment of Cockspur Island has also been affected by spoil material accumulation from dredging efforts within the Savannah River and nearby associated waterways. This protocol was implemented for the first time at Fort Pulaski National Monument in 2019, and these data represent the baseline status of vegetation and associated abiotic elements from the following broadly defined habitats of the park: Maritime Tidal Wetlands and Maritime Upland Forests and Shrublands. Twelve plots were established on these habitats on Cockspur and McQueen’s Island.
Significant Findings
Site and Environmental Factors
In the southeastern Coastal Plain, vegetation diversity is largely influenced by complex soil conditions and their associated relationship with site hydrology and disturbance patterns (e.g., fire). At Fort Pulaski National Monument, these wide-ranging environmental conditions were observed in the landform, soil, and disturbance data collected from vegetation plots. Soil pH values ranged from 3.2 (acidic) to 8.3 (moderately alkaline), with high levels of calcium present in the soil samples of plots from shell middens on McQueen’s Island. Recent disturbances impacting overall vegetation composition patterns were evident in the Maritime Tidal Wetland sites of Cockspur Island and were related to historic legacy of the island’s drainage ditches (i.e., altered hydrology).
Species Diversity and Abundance
Overall plot level plant richness ranged from two to 20 species within these vegetation plots. Species richness was highest in the Maritime Upland Forests and Shrubland habitat type across all plant growth forms, except graminoids. Typical species observed in all plots included southern/eastern red-cedar (Juniperus silicicola + virginiana), cabbage palmetto (Sabal palmetto), yaupon (Ilex vomitoria), groundsel tree (Baccharis halimifolia), sugarberry (Celtis laevigata), tough bully (Sideroxylon tenax), saw greenbriar (Smilax bona-nox), and seaside goldenrod (Solidago mexicana). Other findings related to plant species diversity included:
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Sixty-six plant taxa (genera, species or lower-level taxa) were observed across all plots, including six taxa not previously known from the park.
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Non-native species were encountered in eight of the 12 plots, and included the following species tagged as ‘invasive’ by the Georgia Exotic Pest Plant Council: Japanese honeysuckle (Lonicera japonica), bahiagrass (Paspalum notatum), Vasey’s grass (Paspalum urvillei), and common reed (Phragmites australis). Common reed was not observed in the previous floristic inventory of the park in 1998.
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Two species with elevated conservation status within Georgia were observed during this monitoring effort, including Florida wild privet (Forestiera segregata) and Bosc’s bluet (Oldenlandia boscii); the latter species is new to the park species list.
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Total basal area of trees within Maritime Upland Forest and Shrubland plots ranged from 20 to 40 m2/ha (215.3 to 430.6 ft2/ha). Common trees included southern/eastern red-cedar, cabbage palmetto, and sugarberry.
SECN staff
Other Findings
- More than half of the sugarberry trees measured were given a vigor code other than ‘healthy,’ and all had more than 10% dieback. It is unknown if the decline in these stems is related to the sugarberry die-off issue in other parts of the Southeastern U.S. Future monitoring will detect trends in the overall status of this species on the park.
- All plots were assigned to a community classification type, using NatureServe-defined vegetation associations. Several associations observed at Fort Pulaski National Monument have special conservation value due to their region-wide rarity (Global Status Critically Imperiled [G1] or Global Status Imperiled [G2]). These included Tidal Southern Red-cedar and South Atlantic Coastal Shell Midden Woodlands.
- All plots are scheduled to be resampled in summer 2023.
Full Report
The full report for Terrestrial Vegetation Monitoring at Fort Pulaski National Monument 2020 Data Summary
About the Southeast Coast Network
In 1999, the National Park Service initiated a long-term ecological monitoring program, known as “Vital Signs Monitoring,” to provide the minimum infrastructure to allow more than 270 national park system units to identify and implement long-term monitoring of their highest-priority measurements of resource condition. The overarching purpose of natural resource monitoring in parks is to develop scientifically sound information on the current status and long-term trends in the composition, structure, and function of park ecosystems, and to determine how well current management practices are sustaining those ecosystems.
The NPS Vital Signs Monitoring Program addresses five goals for all parks with significant natural resources:
- Determine the status and trends in selected indicators of the condition of park ecosystem,
- Provide early warning of abnormal conditions,
- Provide data to better understand the dynamic nature and condition of park ecosystems,
- Provide data to meet certain legal and Congressional mandates, and
- Provide a means of measuring progress towards performance goals.
The Southeast Coast Network (SECN) includes eighteen administrative areas containing twenty park units, fifteen of which contain significant and diverse natural resources. In total, SECN parks encompass more than 184,000 acres of federally-managed land across North Carolina, South Carolina, Georgia, Alabama, and Florida. The parks span a wide diversity of cultural missions, including four national seashores, two national historic sites, two national memorials, six national monuments, two national military parks, as well as a national recreation area, national battlefield, national historical park, and an ecological and historic preserve. The parks range in size from slightly more than 20 to nearly 60,000 acres, and when considered with non-federal lands jointly managed with the National Park Service, the network encompasses more than 253,000 acres.
For More Information
SECN Home Page
https://www.nps.gov/im/secn/index.htm
SECN Reports & Publications
https://www.nps.gov/im/secn/reports-publications.htm
About the NPS Inventory & Monitoring Program
https://www.nps.gov/im/index.htm
Data Downloads via the Natural Resource Information Portal
https://irma.nps.gov/Portal/