Last updated: May 16, 2024
Article
Terrestrial Vegetation Monitoring 2022 Data Summary for Cape Lookout National Seashore
Overview
Vegetation communities are dynamic entities influenced by environmental factors and impacts 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 therefore 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 a 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. Permanent plots are used as the sample unit to determine a site’s (1) vascular plant richness and abundance for all native and non-native species; (2) basal area, density and health for all woody species; (3) density of forest floor fuels; (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
Cape Lookout National Seashore (CALO) covers approximately 11,430 hectares (28,243 acres) along a 91 kilometer (56.5 mile) stretch of the Atlantic Ocean in eastern North Carolina from Pamlico Sound and Ocracoke Inlet to Beaufort Inlet. The seashore is composed of three barrier islands—North Core Banks, South Core Banks, and Shackleford Banks—separated from the North Carolina mainland by Core and Back Sound. The vegetation communities along Cape Lookout National Seashore range from open beach and foredune grasslands on the ocean-facing side to tidal marshes on the sound-facing side. Between is a mixture of interdune swales, backdunes, and enclosed wetlands. This protocol was first implemented in the park in 2022, and these data represent the baseline status of vegetation and associated abiotic elements from the following broadly defined habitats of the park: Maritime Open Uplands, Maritime Upland Forests and Shrublands, Maritime Nontidal Wetlands, and Maritime Tidal Wetlands. Forty-nine plots were established in May and June 2022 across four subunits—North Core Banks, South Core Banks, Cape Lookout, and Shackleford Banks (see map).
Significant Findings
Site and Environmental Factors
In the southeastern Coastal Plain, vegetation diversity is influenced by complex edaphic factors and their relationship with site hydrology and disturbance patterns (e.g., fire, storms). At Cape Lookout National Seashore, these environmental conditions were observed in the landform, soil, and disturbance data collected from vegetation plots. Soil pH values ranged from acidic to slightly alkaline (4.5 to 8.7) and complex topography was evident within ridges and swales of both young and old dune systems. Cape Lookout National Seashore ecosystems have always been subjected to high frequencies of wind-, tide-, and wave-driven processes that sculpt vegetation composition and structure. Human-caused disturbances (e.g., historical plowing, shifting fire regimes, and altered hydrology) affecting plant communities within other SECN parks were not observed within these plots during this survey effort. Stunted plant growth was observed on several plots of Shackleford Banks and likely caused by feral horse grazing. It is unclear from these data if grazing has impacted overall vegetation diversity and structure patterns across the island.
Vegetation
One hundred and eighty-six plant species were observed across all plots, including 11 taxa not detected in previous plant surveys and 15 species listed as rare by the North Carolina Natural Heritage Program. Rare species were encountered throughout all habitats surveyed within the park but were most frequently observed in Nontidal Wetland and Upland Forest habitat. Overall plot level native plant richness ranged from four to 48 species with highest richness found in Upland Forests and Shrublands of Shackleford Banks. Graminoid and herbaceous species dominated both Nontidal and Tidal wetland sites within the park.
Non-native species were infrequent across Cape Lookout National Seashore and no nonnative species were observed within Tidal Wetlands. Two Rank 1 invasive plants were observed in plots during this monitoring effort, including Japanese honeysuckle (Lonicera japonica) and common reed (Phragmites australis).
Other Findings
- Fifteen species listed as rare and tracked by the North Carolina Natural Heritage Program were observed during this monitoring effort, including the state threatened blue witchgrass (Dichanthelium caerulescens).
- Sand live oak (Quercus geminata) was a canopy co-dominant in a single plot located on the Shackleford Banks. This species of oak, which is closely related to the more common live oak, has not been reported along the Outer Banks of North Carolina.
- Grazing within both Open Uplands and Nontidal Wetland sites by feral horses (Equus caballus) was observed on Shackleford Banks. Shore little bluestem (Schizachyrium littorale), a rare species in North Carolina, was observed within dune plots of North Core Banks and Cape Lookout subunit, but was not present on dunes of Shackleford Banks.
- All plots are scheduled to be resampled in spring or summer 2026
Full Report
Terrestrial Vegetation Monitoring at Cape Lookout National Seashore 2022 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 and Publications
(https://www.nps.gov/im/secn/reports-publications.htm)
NPS Inventory and Monitoring Program
(https://www.nps.gov/im/index.htm)
Data Downloads via the Natural Resource Information Portal
(https://irma.nps.gov/portal/)