Habitat Priorities

Surveys

Determine the status of Yellow-crowned Night-heron, other colonial nesting birds, Wayne's Black-throated Green Warbler, as well as other neotropical migrants that are not well sampled by BBS. (Surveys Priority)
Document the status and distribution of priority bat species (e.g. Rafinesque's Big-eared Bat, Northern Yellow Bat, Seminole Bat, Southeastern Bat, and Northern Long-eared Bat) in this habitat. (Surveys Priority)
Conduct Eastern Woodrat surveys and subsequently establish standardized long-term monitoring of the species in this habitat. (Surveys Priority)
Determine the status and distribution of Timber (Canebrake) and Pigmy rattlesnakes. (Surveys Priority)
Survey for other SGCN and high priority species, especially snakes and lizards. (Surveys Priority)

Monitoring

Establish long-term monitoring for neotropical migrants that are not well tracked by BBS in this habitat type.

Research

Conduct home-range and movement research on Timber (Canebrake) and Pigmy Rattlesnakes (possibly on other snakes of conservation concern as well).
Conduct genetics research to determine if the Coastal Worm-eating Warbler is a separate sub-species.
Explore alternatives (herbicides or mechanical) to using fire for the initial restoration of severely fire suppressed non-alluvial wetlands.
Determine why some priority species use this habitat on the coast, when the same species primarily is found in the Mountains using completely different habitats (e.g., Wayne's Black-throated Green Warbler, Worm-eating Warbler, Wood Frog).

Management Practices

Reintroduction of fire to unconverted nonalluvial mineral wetland sites is the single most important factor to restore these sites.
Plowed firelines along transition zones between habitats should be rehabilitated (smoothed over) where possible. New firelines should be constructed when necessary. These areas should be maintained as a permanent narrow opening by discing with a tractor or by wetting with water or foam prior to a burn.
Control tide water penetration and saltwater intrusion with tide gates where feasible.
Where fire cannot be introduced back into the site for smoke management or other reasons, the use of a hydro-ax or other chipping machinery should be considered to control midstory.

Conservation Programs and Partnerships

Description

Nonalluvial mineral wetlands occur on flat, poorly drained areas of the outer Coastal Plain and occasionally in shallow depressions such as Carolina bays. There may also be sites that fit this community description located in the Sandhills ecoregion. The soils in these sites are saturated in the wetter seasons, may have shallow standing water, and do not experience overflow flooding. The wetness comes from poor drainage and sheet flow from adjoining peatlands. The soils are less acidic and infertile than the peat soils of pocosins, but they do not have the regular nutrient input of river floodplains. Organic deposits are generally lacking, though occasional examples are found on organic soils where some other factor offsets the tendency of these soils to support pocosins.

In the wettest areas, bald cypress, swamp black gum, and red maple dominate. Where these areas transition to peatland, loblolly pine, pond pine, and Atlantic white cedar may also be present. In less saturated nonalluvial wetlands, trees characteristic of bottomland hardwood systems dominate: cherrybark oak, laurel oak, swamp chestnut oak, tulip poplar, sweetgum, American elm, and red maple. There are three community types that differ in wetness and the nature of the soil: non-riverine swamp forests, non-riverine wet hardwood forests, and wet marl forest.

Non-riverine swamp forests occur in the wettest sites. They are dominated by trees tolerant of extreme wetness, such as bald cypress, swamp black gum, and red maple. A distinctive variant, transitional to peatland communities, has these species mixed with loblolly pine, pond pine, and Atlantic white cedar.
Non-riverine wet hardwood forests occur in less wet areas. They are dominated by trees typically called “bottomland hardwoods.” The undergrowth is usually open beneath the closed canopy, but sometimes dense cane or shrubs occur.
The wet marl forest type occurs where marl or limestone occurs near the surface and affects the soil. This extremely rare community is completely isolated, and is fragmented. Although they are wet, these soils are not acidic and are more fertile than most Coastal Plain soils. The vegetation is dominated by a diverse mixture of tree, shrub, and herb layers. Dwarf palmetto is an abundant and distinctive part of the shrub layer.
The 2005 WAP described Mid-Atlantic Coastal Plain nonalluvial mineral wetlands as a priority habitat (see Chapter 5)(NCWRC 2005).

Location of Habitat

Examples of this habitat type can be found in the Alligator River, Swanquarter, and Great Dismal Swamp National Wildlife Refuges, Hoffmann Forest, Rocky Point, and several swamps (Van and East Dismal) in Washington County.

Problems Affecting Habitats

The condition of nonalluvial mineral wetlands in the Coastal Plain is generally poor due to alteration of hydrology (primarily from draining for farmland and conversion to loblolly pine plantations) and is rather fragmented. Some of the best remaining examples are on public lands such as on Alligator River National Wildlife Refuge, Swanquarter National Wildlife Refuge, and the Great Dismal Swamp National Wildlife Refuge.

Nonalluvial mineral wetlands tend to be converted for forestry and agriculture more readily since the mineral soils can support heavy equipment better than organic soils, and they are more fertile. Much of this type existed in Beaufort and Pamlico counties until recent years; relatively little remains. A higher percentage of this habitat type has probably been destroyed than any other type in the Coastal Plain, with the exception of dry longleaf pine.

Fire suppression has led to a decline in diversity of these habitats but the alteration of hydrology from ditches associated with farming and forestry practices is the biggest factor impacting this habitat type. Altered hydrology that drains these wetland types will decrease the ability to use prescribed fire as a management tool and increase the risk of catastrophic damage from wildfire. Non-native plant species (e.g., Chinese Privet, Japanese Stiltgrass) are also competing with native vegetation in many areas, especially those frequently disturbed. Although little of this quality habitat remains, it can be burned more safely than those sites with organic soils. Therefore, the potential still exists to reestablish some high-quality nonalluvial mineral wetlands on the Coastal Plain of North Carolina, where it has not already been converted to farmland or ditched for pine plantations.

Climate Change Compared to Other Threats

Comparing climate change to other ecosystem threats can help define short and long-term conservation actions and recommendations. While climate change is not the most severe threat, a combination of synergistic effects with other existing conditions could stress these systems to the point where several species are unable to persist.

Climate change is a significant threat primarily because of the likelihood of inundation from sea level rise. Rising sea level will be more of a concern in the larger riverine wetlands at lower elevations, such as those around the Alligator River, than wetlands further inland. However, other threats such as logging and the alteration of hydrology, in the form of ditches, pose equal threats to these systems.

Impacts to the non-riverine swamps and hardwood stands in the Albemarle–Pamlico Peninsula, which include the largest blocks of habitats of this ecosystem group in the state, are likely to be catastrophic. These stands are unlikely to be replaced by the development of new stands located farther inland.

Impacts to Wildlife

These sites are important for variety of neotropical migrants during the breeding season and migration periods (Hunter et al. 2000b; Johns 2004), and also several reptiles of conservation concern (NCWRC 2005). Wayne’s Black-throated Green Warbler is nearly confined to non-riverine swamp forests throughout its narrow range from Virginia to South Carolina. This taxon is declining throughout its range, and loss of the population on the Albemarle–Pamlico Peninsula (believed to be the largest remaining) due to rising sea levels would significantly reduce the chances of its survival overall. Storm-related impacts to the Wayne’s Black-throated Green Warbler could be particularly severe, since it is a canopy-dwelling species that is often found in the vicinity of tall conifers (likely nesting sites) that emerge above a canopy of hardwoods (Fussell et al. 1995). Likewise, the coastal population of the Worm-eating Warbler uses this habitat type heavily and is isolated from other populations that breed in the Mountains of North Carolina.

Even more likely to become extirpated is the sole population of Wood Frogs known to occur in the Coastal Plain of North Carolina. This population exists on the Albemarle–Pamlico Peninsula in the vicinity of hardwoods near Scranton and likely represents a relic from the Pleistocene epoch, as do several other animals and plants recorded in this area (e.g., cranberry, Sundew moth, undescribed shrew). The reasons for its restricted range in this area are unknown, but it may not be able to migrate inland to keep pace with sea level rise.

Nonriverine mineral wetlands are the primary habitat for the Red Wolf in the state, with most individuals being present at Alligator River and Pocosin Lakes refuges. Other large mammals also utilize these habitats, such as Black Bear, Bobcat, and White-tailed Deer.

Other terrestrial vertebrates and invertebrates associated with this ecosystem group occupy other types of habitat, including floodplain forests and peatlands, and are more likely to survive impacts associated with climate change. Two species of Canebrake Moths, however, are endemic to the North Carolina Coastal Plain and the portion of the Great Dismal Swamp in Virginia: Lascopia roblei and the still-undescribed Apameine, new genus 2, species 3. Some of their largest known populations are associated with non-riverine habitats, the loss of which would be significant, if not as damaging as for Wayne’s Black-throated Green Warbler.

quoted from the 2015 North Carolina Wildlife Action Plan

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Nonalluvial Mineral Wetlands

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