Terrestrial vegetation monitoring at Cape Hatteras National Seashore: 2019 data summary

The Southeast Coast Network (SECN) conducts long-term terrestrial vegetation monitoring as part of the nationwide Inventory and Monitoring Program of the National Park Service (NPS). The vegetation community vital sign is one of the primary-tier resources identified by SECN park managers, and monitoring is currently conducted at 15 network parks (DeVivo et al. 2008). Monitoring plants and their associated communities over time allows for targeted understanding of ecosystems within the SECN geography, which provides managers information about the degree of change within their parks’ natural vegetation. The first year of conducting this monitoring effort at four SECN parks, including 52 plots on Cape Hatteras National Seashore (CAHA), was 2019. Twelve vegetation plots were established at Cape Hatteras NS in July and August. Data collected in each plot included species richness across multiple spatial scales, species-specific cover and constancy, species-specific woody stem seedling/sapling counts and adult tree (greater than 10 centimeters [3.9 inches {in}]) diameter at breast height (DBH), overall tree health, landform, soil, observed disturbance, and woody biomass (i.e., fuel load) estimates. This report summarizes the baseline (year 1) terrestrial vegetation data collected at Cape Hatteras National Seashore in 2019. Data were stratified across four dominant broadly defined habitats within the park (Maritime Tidal Wetlands, Maritime Nontidal Wetlands, Maritime Open Uplands, and Maritime Upland Forests and Shrublands) and four land parcels (Bodie Island, Buxton, Hatteras Island, and Ocracoke Island). Noteworthy findings include: A total of 265 vascular plant taxa (species or lower) were observed across 52 vegetation plots, including 13 species not previously documented within the park. The most frequently encountered species in each broadly defined habitat included: Maritime Tidal Wetlands: saltmeadow cordgrass Spartina patens), swallow-wort (Pattalias palustre), and marsh fimbry (Fimbristylis castanea) Maritime Nontidal Wetlands: common wax-myrtle (Morella cerifera), saltmeadow cordgrass, eastern poison ivy (Toxicodendron radicans var. radicans), and saw greenbriar (Smilax bona-nox) Maritime Open Uplands: sea oats (Uniola paniculata), dune camphorweed (Heterotheca subaxillaris), and seabeach evening-primrose (Oenothera humifusa) Maritime Upland Forests and Shrublands: : loblolly pine (Pinus taeda), southern/eastern red cedar (Juniperus silicicola + virginiana), common wax-myrtle, and live oak (Quercus virginiana). Five invasive species identified as either a Severe Threat (Rank 1) or Significant Threat (Rank 2) to native plants by the North Carolina Native Plant Society (Buchanan 2010) were found during this monitoring effort. These species (and their overall frequency of occurrence within all plots) included: alligatorweed (Alternanthera philoxeroides; 2%), Japanese honeysuckle (Lonicera japonica; 10%), Japanese stilt-grass (Microstegium vimineum; 2%), European common reed (Phragmites australis; 8%), and common chickweed (Stellaria media; 2%). Eighteen rare species tracked by the North Carolina Natural Heritage Program (Robinson 2018) were found during this monitoring effort, including two species—cypress panicgrass (Dichanthelium caerulescens) and Gulf Coast spikerush (Eleocharis cellulosa)—listed as State Endangered by the Plant Conservation Program of the North Carolina Department of Agriculture and Consumer Services (NCPCP 2010). Southern/eastern red cedar was a dominant species within the tree stratum of both Maritime Nontidal Wetland and Maritime Upland Forest and Shrubland habitat types. Other dominant tree species within CAHA forests included loblolly pine, live oak, and Darlington oak (Quercus hemisphaerica). One hundred percent of the live swamp bay (Persea palustris) trees measured in these plots were experiencing declining vigor and observed with symptoms like those caused by laurel wilt......less

Forecasting oceanfront shoreline position to evaluate physical vulnerability for recreational and infrastructure resilience at Cape Hatteras National Seashore

The Cape Hatteras National Seashore (Seashore) is located along the Outer Banks of eastern North Carolina, and is renowned for its prominent historical landmarks and world-class recreation. Seashore managers maintain hundreds of assets that support visitor use. Additionally, and primary to the mission of the National Park Service (NPS), managers steward natural and cultural resources located on public and protected lands. The portfolio of assets managed by NPS within the Seashore carries a high level of risk due to its exposure to both coastal erosion and storm surge inundation. The impacts of Hurricane Dorian demonstrated the importance of examining the physical vulnerability of the entire portfolio managed by NPS within the Seashore. The purpose of this study was to 1) evaluate the functionality of the beta forecast tool available in the Digital Shoreline Analysis System (v 5.0); and 2) explore options for using the output to assess the potential physical vulnerability of NPS assets. The study determined that using the 10- and 20-year oceanfront shoreline position forecast provides decision makers with a first order screening tool that can be used to prioritize mitigation and adaptation strategies given the unpredictable nature of tropical and extra-tropical cyclones and uncertainty associated with sea level rise.

Post-Dorian shoreline change at Cape Hatteras National Seashore: 2019 report

In 2018 and 2019 the Southeast Coast Network (SECN), with assistance from park staff, collected long-term shoreline monitoring data at Cape Hatteras National Seashore as part of the National Park Service (NPS) Vital Signs Monitoring Program. Monitoring was conducted following methods developed by the NPS Northeast Coastal and Barrier Network and consisted of mapping the high-tide swash line using a Global Positioning System unit in the spring of each year (Psuty et al. 2010). Shoreline change was calculated using the Digital Shoreline Analysis System (DSAS) developed by the United States Geological Survey (USGS; Himmelstoss et al. 2018). Following the same field methods used for monitoring long-term shoreline change, geospatial data were collected as part of the Hurricane Dorian (or Dorian) Incident Response from September 12–16, 2019. This report summarizes the post-Dorian data and the previous two shoreline data collection efforts (spring 2019 and fall 2018).