Habitats of North Carolina
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Floodplain Forests
Rich Wet-Mesic Hardwood Forests
General Description The hardwood forests that comprise this habitat are associated nutrient-rich soils and cool, shaded, and humid microclimates. Over most of the state, these conditions occur on forested slopes with underlying mafic or other base-rich rock formations. They are particularly associated with slopes that have east- or north-facing exposures, limiting insolation especially during the hottest parts of the day. Species in this habitat are not restricted to slopes, however. They are tolerant of short-term flooding and can occur well out into rich bottomlands.

These conditions are relatively frequent in the Mountains, especially in rich cove forests and northern hardwood forests, and are also widespread, if scattered, across the Piedmont. In the Coastal Plain, the largest examples are associated with brownwater rivers, which carry sediments derived from rich soils in the Mountains and Piedmont. These sediments coat not only the floodplain but are often deposited well up on the adjoining slopes. This is especially true for the lower Roanoke valley, where the rich sediments reach all the way to the top of the bluffs, completely covering the sandy soils that are typical of the Coastal Plain (LeGrand and Hall, 2014). A few isolated examples are associated with areas closely underlain by marl, a calcium-rich rock formed from deposits of fossil mollusk shells.

With 137 species identified so far as belonging to this habitat, this is one of the most biodiverse of any found within the state. For both plants and many species of the invertebrates, this reflects the sheltered, cool, moist conditions as well as the high pH and abundance of nutrients needed by the plants. It also reflects the long biogeographic history of mesic forests in the Southern Appalachians, the center of diversity for many of the taxonomic groups that characterize this habitat.

This habitat strongly overlaps with others that are also associated with nutrient-rich, high pH soils. These include Rich Wet Hardwood Forests, whose Determining Species are much more confined to the wet soils of bottomlands; the Rich Dry-Wet Hardwood Forests, whose species occupy the widest moisture range in this group, occurring on dry ridges down to floodplains; and the Rich Dry-Mesic Hardwood Forests, whose species are highly flood-intolerant and occur only in uplands, but only where the soils are high in nutrients and pH.

Other intersecting types of hardwood-dominated habitats require cool, moist conditions but are not as tied to high nutrient soils. These include the General Wet-Mesic Hardwood Forests and General Mesic Hardwood Forests. Others are less general in distribution and occur in either the Mountains or the Coastal Plain.

Abiotic Factors Geographic Regions: Lower Coastal Plain to High Mountains. USDA Hardiness Zones: 6-8. Landform: slopes, bottomlands, and wet flats and occasionally on ridges. Slope Aspect: north and east facing on slopes, otherwise flat. Soil Moisture: Mesic to wet. Soil texture: loamy to silty, permitting burrowing by fossorial species; rocks are often present on the slopes and in the mountains extensive areas of talus can be present. Soil pH: circumneutral. Soil Nutrient Content: rich in mafic or calcareous minerals. Microclimate: Cool and humid. Hydrological Features: springs and seeps are common, particularly at the interface between slopes and bottomlands. Flood Frequency: upper slopes usually never flood but lower slopes and bottomlands may flood several times per year. Flood Duration: hours to days in the bottomlands and lower slopes. Fire Frequency: very rare. Drought Frequency: uncommon to rare. Ice Storm Damage: low to moderate. Wind Storm Damage: moderate. Insolation: canopies are well insolated, lower strata are deeply shaded.

Biotic Structure Vegetation Type: Closed-canopy forests composed of broadleaf, deciduous trees (Loblolly Pines may be present but are not a key feature). Strata Subcanopy, shrub, and herb-layers well-developed and often lush. Woody debris and leaf litter plentiful except in flood channels or other areas frequently scoured by floods.

Co-evolved Species Groups Phagic and Competitory Symbioses:
Acer floridanum-Acer saccharum //Cameraria saccharella-Peridea basitriens-Phyllonorycter lucidicostella
Aesculus species // Cameraria aesculisella-Trigrammia quadrinotaria complex
Apocarya Hickory species // Catocala agrippina-Catocala nebulosa
Asimina species // Eurytides marcellus-Omphalocera munroei-Talponia plummeriana
Cardamine species // Anthocharis midea
Carya cordiformis // Catocala subnata
Carya laciniosa-Carya ovata // Catocala luctuosa
Juglans nigra // Baileya australis-Caloptilia blandella-Hypena madefactilis
Juglans species // Acrobasis juglandis-Catocala neogama-Hypena madefactalis-Pediopsoides distinctus
Laportea canadensis // Hypena sordidula
Podophyllum peltatum // Papaipema rutila
Trillium species // Scopula ordinata
Ulmus species // Acronicta morula-Nerice bidentata
Urticaceae species // Hypena humuli-Polygonia comma

Host // Commensal Symbioses:
(host-specific lichens and bryophytes)
(host specific decomposers)

Flower // Pollinator Mutualistic Symbioses:
Geranium maculatum // Andrena distans
Claytonia virginica // Andrena eriginiae

(Host/Disperser Associations)

Competitor Guilds:
Light Competitors:
Florida Maple is shade-tolerant (Jones, 1990) persists under climax conditions. Bitternut Hickory and Black Walnut are shade-intolerant (Smith, 1990; Williams, 1990); Black Walnuts produce allelopathic chemicals that limit the growth of competing tree species. Shagbark Hickory is intermediate in terms of shade tolerance but is a climax species in many stands (Graney, 1990). Slippery Elm and Sugarberry are shade-tolerant (Cooley and Sambeek, 1990; Kennedy, 1990).

Determining Species
Taxa Global RankState RankProbability of Extirpation (PE)
Acer floridanum - Florida Maple G4G5S50.00
Carya cordiformis - Bitternut Hickory G5S40.0007
Carya ovata - Shagbark Hickory G5S40.0007
Celtis laevigata - Sugarberry G5S50.00
Juglans nigra - Black Walnut G5S40.0007
Magnolia macrophylla - Bigleaf Magnolia G5S20.0460
Morus rubra - Red Mulberry G5S50.00
Ulmus rubra - Slippery Elm G5S50.00
Aconitum uncinatum - Southern Blue Monkshood G4S3S40.0020
Actaea pachypoda - White Baneberry G5S40.0007
Actaea racemosa - Black Cohosh G5S40.0007
Amsonia tabernaemontana - Eastern Bluestar G5S50.00
Arisaema dracontium - Green Dragon G5S3S40.0020
Aruncus dioicus - Eastern Goat's-beard G5S40.0007
Asarum reflexum - Reflexed Wild-ginger GNRS4S50.0002
Cardamine angustata - Slender Toothwort G5S40.0007
Cardamine concatenata - Cutleaf Toothwort G5S40.0007
Cardamine diphylla - Two-leaved Toothwort G5S50.00
Cardamine dissecta - Forkleaf Toothwort G4S20.0460
Cardamine douglassii - Limestone Bittercress G5S20.0460
Caulophyllum thalictroides - Common Blue Cohosh G5S50.00
Chaerophyllum procumbens - Spreading Chervil G5S30.0058
Circaea canadensis - Broadleaf Enchanter's-nightshade G5S50.00
Claytonia virginica - Virginia Spring-beauty G5S50.00
Collinsonia canadensis - Canada Horsebalm G5S50.00
Collinsonia tuberosa - Deepwoods Horsebalm G3G4S1S20.1284
Coreopsis tripteris - Tall Tickseed G5S30.0058
Corydalis flavula - Yellow Fumewort G5S40.0007
Cryptotaenia canadensis - Canadian Honewort G5S50.00
Cypripedium parviflorum - Yellow Lady's-slipper G5S30.0058
Delphinium tricorne - Dwarf Larkspur G5S30.0058
Dicentra cucullaria - Dutchman's Breeches G5S40.0007
Enemion biternatum - False Rue-anemone G5S20.0460
Erigenia bulbosa - Harbinger-of-spring G5S10.3584
Erythronium americanum - Yellow Trout-lily G5S30.0058
Euonymus atropurpureus - Eastern Wahoo G5S20.0460
Euphorbia obtusata - Woodland Spurge G4S30.0058
Eurybia mirabilis - Bouquet Aster G3S30.0058
Galearis spectabilis - Showy Orchis G5S40.0007
Geranium maculatum - Wild Geranium G5S50.00
Geum canadense - White Avens G5S50.00
Geum virginianum - Cream Avens G5S40.0007
Hydrophyllum canadense - Bluntleaf Waterleaf G5S40.0007
Hylodesmum glutinosum - Pointedleaf Tick-trefoil G5S20.0460
Iris cristata - Dwarf Crested Iris G5S50.00
Laportea canadensis - Canada Wood-nettle G5S50.00
Menispermum canadense - Canada Moonseed G5S40.0007
Mertensia virginica - Virginia Bluebells G5S20.0460
Nanopanax trifolius - Dwarf Ginseng G5S30.0058
Nemophila aphylla - Small-flower Baby-blue-eyes G5S40.0007
Panax quinquefolius - American Ginseng G3G4S3S40.0020
Persicaria virginiana - Jumpseed G5S50.00
Phacelia covillei - Coville's Phacelia G3S30.0058
Podophyllum peltatum - Mayapple G5S50.00
Polemonium reptans - Creeping Jacob's-ladder G5S10.3584
Ranunculus micranthus - Rock Buttercup G5S10.3584
Sanguinaria canadensis - Bloodroot G5S50.00
Scrophularia marilandica - Late Figwort G5S30.0058
Smallanthus uvedalia - Hairy Leafcup G5S50.00
Symphyotrichum phlogifolium - Thinleaf Late Purple Aster G5S30.0058
Thaspium barbinode - Hairy-jointed Meadow-parsnip G5S50.00
Tiarella cordifolia - Heartleaf Foamflower G5S50.00
Tradescantia virginiana - Virginia Spiderwort G5S2S30.0164
Trillium cuneatum - Little Sweet Trillium G4G5S30.0058
Viola eriocarpa - Smooth Yellow Violet G5S50.00
Viola walteri - Prostrate Blue Violet G4G5S10.3584
Acrobasis demotella - Walnut Shoot Moth GNRS3S40.0020
Acrobasis juglandis - Pecan Leaf Casebearer Moth GNRSU0.0020
Acrobasis latifasciella GNRS2S30.0164
Acronicta hamamelis - Witch Hazel Dagger G4S3S40.0020
Acronicta morula - Ochre Dagger G5S3S40.0020
Baileya australis - Small Baileya G5S4S50.0002
Baileya dormitans - Sleeping Baileya G5S4S50.0002
Baileya levitans - Pale Baileya G5S40.0007
Besma endropiaria - Straw Besma Moth G5S50.00
Caloptilia blandella GNRS3S40.0020
Cameraria aesculisella GNRSU0.0020
Canarsia ulmiarrosorella - Elm Leaftier Moth GNRS3S40.0020
Catocala agrippina - Agrippina Underwing Moth G5S2S40.0058
Catocala luctuosa - Hulst's Underwing Moth G4S10.3584
Catocala maestosa - Sad Underwing G5S3S40.0020
Catocala nebulosa - Clouded Underwing G5S40.0007
Catocala neogama - Bride Underwing G5S40.0007
Catocala orba - Orb Underwing G4S2S30.0164
Catocala piatrix - Penitent Underwing G5S40.0007
Catocala subnata - Youthful Underwing G5S3S40.0020
Dypterygia rozmani - American Bird's-wing Moth G5S3S40.0020
Glaucolepis saccharella GNRSU0.0020
Hypena abalienalis - White-lined Bomolocha G5S3S40.0020
Hypena humuli - Hop Vine Moth G5S3S40.0020
Hypena madefactalis - Gray-edged Bomolocha G5S4S50.0002
Hypena sordidula - Sordid Bomolocha G4S3S40.0020
Nerice bidentata - Double-toothed Prominent G5S40.0007
Omphalocera munroei - Asimina Webworm Moth GNRS3S40.0020
Papaipema polymniae - Cup Plant Borer G4SU0.0020
Papaipema rutila - Mayapple Borer G4S2S30.0164
Peridea basitriens - Oval-Based Prominent G5S40.0007
Phyllonorycter lucidicostella - Lesser Maple Leaf Blotch Miner Moth GNRSU0.0020
Scopula ordinata GUS3S40.0020
Talponia plummeriana - Speckled Talponia Moth GNRS2S40.0058
Trigrammia quadrinotaria - Four-spotted Angle G4S40.0007
Adiantum pedatum - Northern Maidenhair Fern G5S50.00
Amauropelta noveboracensis - New York Fern G5S50.00
Athyrium asplenioides - Southern Lady Fern G5S50.00
Phegopteris hexagonoptera - Broad Beech Fern G5S50.00
Aesculus sylvatica - Painted Buckeye G5S50.00
Asimina triloba - Common Pawpaw G5S50.00
Calycanthus floridus - Sweetshrub G5S50.00
Cornus alternifolia (= Swida alternifolia) - Alternate-leaf Dogwood G5S40.0007
Crataegus spathulata - Littlehip Hawthorn G5S1S20.1284
Dirca palustris - Eastern Leatherwood G4S30.0058
Philadelphus inodorus - Scentless Mock-orange G4G5S30.0058
Staphylea trifolia - American Bladdernut G5S40.0007
Ampelopsis cordata - Heartleaf Peppervine G5S20.0460
Smilax hispida - Bristly Greenbrier G5S50.00
Vitis labrusca - Fox Grape G5S40.0007
Vitis riparia - Riverbank Grape G5S20.0460
Andrena distans
Andrena erigeniae
Anthocharis midea - Falcate Orangetip G5S50.00
Eurytides marcellus - Zebra Swallowtail G5S50.00
Polygonia comma - Eastern Comma G5S50.00
Polygonia interrogationis - Question Mark G5S50.00
Bromus pubescens - Hairy Woodland Brome G5S40.0007
Carex blanda - Eastern Woodland Sedge G5S40.0007
Carex bromoides ssp. bromoides - Brome-like Sedge G5T5S30.0058
Carex crebriflora - Coastal Plain Sedge G4S20.0460
Carex jamesii - James's Sedge G5S20.0460
Chasmanthium latifolium - River Oats G5S40.0007
Elymus macgregorii - Early Wild-rye G5S30.0058
Leersia virginica - White Cutgrass G5S50.00
Luzula acuminata - Hairy Woodrush G5S40.0007
Poa cuspidata - Early Bluegrass G5S40.0007
Conotrachelus retentus -
Corythucha juglandis
Dikrella maculata
Pediopsoides distinctus
Geothlypis formosa - Kentucky Warbler G5S3S40.0020
Expected Number of Extirpations with a PE value (Sum of PE) = 2.7848
N = Number of Extant Species with a PE value = 95
Average PE = ENE/N = 0.0293
Number of S5 species = 36
Proportion of Secure Species = Number of S5 Species/N = 0.3789
Habitat Risk Index = ENE x (1 – PSS) = 1.7296

Estimated Risk to the Determining Species Seven species in this habitat are state-ranked as S1 or S1S2; 11 listed as S2. Of these, thirteen (72%) are at the edge of their ranges in North Carolina, with the heart of their distribution in the Mid-west. Although they are not restricted to the small areas of limestone found in North Carolina, their distribution may mean that they are probably primarily calciphilic in their habitat preferences and only somewhat adapted to using mafic substrates and their much smaller amounts of calcium. As such, they may not be as representative of this habitat as the others whose ranges are more centered in the southern Atlantic Slope.

Excluding those thirteen species, the average Probability of Extirpation drops from 0.02101
to 0.00789. In our model of extirpation probabilities, that is equivalent to a state rank of S3, which is considered of only potential conservation concern.

Estimated Security of the Habitat 35 species are listed as S5, or completely secure within North Carolina. The Proportion of Secure species is 0.26, or 0.29 following the exclusion of the anomalous Mid-western Species. This is a moderately high value, indicating that the habitat overall is well-distributed across the state, occupying a few very large expanses particularly in the Mountains, but with a larger number of smaller, but well-connected occurrences in the Piedmont and Coastal Plain.

Index of Habitat Imperilment
Identified Risks The steep slopes and floodplains occupied by this habitat are somewhat protected from development or conversion to agriculture. Steep slopes are also somewhat safe from timber harvest. Upland habitats, however, are all vulnerable to at least some form of residential development and in the case of steep slopes, there can be secondary impacts from adjacent development even when the slopes themselves are spared. These impacts include increased insolation if the ridge tops are deforested, leading to increased heating and drying of the slopes below. Erosion is also likely to increase, due to stormwater runoff from the developed area or from construction of non-carefully designed trails. Non-buildable slopes are also the sites where landscaping fill, sewerlines, pump stations, and other infrastructure serving the development are often placed, usually involving forest clearance. Additionally, runoff of landscaping chemicals, escape of exotic species, invasion of the natural habitats by pets, and increased populations of human tolerant wildlife, including deer, coyotes, raccoons, skunks, squirrels, etc. can have major impacts on all adjacent natural areas. Deer overbrowsing -- due to the great increase in their numbers -- is having a particular impact on the shrub and herb layers of the forest. In addition to the plants, this is having an impact on moths and other herbivorous species of insects, as well as the Kentucky Warbler that requires both rich herbs and shrub cover for nesting and foraging (Tymkiw, 2010; Magee and Van Clef, 2016; H. Wiley, pers. comm. to Hall).

Augmenting these impacts, mesic slopes will become increasingly vulnerable to droughts and fire due to the effects of climate change. This is also true for wet bottomlands, which are subject to different set of impacts than the slopes, as described in several of the habitats more closely confined to floodplains (e.g., see Rich Wet Hardwood Forests).

Observed Trends Residential development along river and stream bluffs and hill crests are common sights in the urbanizing portions of the Piedmont; how much damage this is doing to the slopes below is not well documented.

Distribution Map
Distribution Examples of this habitat occur from the high mountains to the lower Coastal Plain but are less well represented in the Coastal Plain, due to its typically acidic, nutrient-poor soils, except along the brownwater rivers.

Major Conservation Reserves For preserves for rich floodplains, see Rich Wet Hardwood Forests. For rich mesic slopes, the following areas represent major preserves. In the Mountains: GSMNP; Joyce-Kilmer and other wilderness or designated areas in the Nantahala Pisgah National Forests; Gorges, Chimney Rock, Mt. Mitchell, Grandfather Mountain, New River, Mt. Jefferson, Stone Mountain State Parks; 31 state game lands (see https://www.ncwildlife.org/Hunting/Where-To-Hunt-Shoot/Public-Places/Mountain-Game-Land-Maps); plus several privately owned nature preserved. In the Piedmont: South Mountains, Pilot Mountain, Hanging Rock, Mayo River, Eno River, Raven Rock, Medoc Mountain, and Morrow Mountain State Parks, Occoneechee Mountain State Natural Area; wilderness and designated natural areas in the Uwharrie National Forest; 28 state game lands; and several privately owned preserves. In the Coastal Plain: steep coastal bluffs in the Croatan National Forest and Camp Lejuene Marine Corps Base.

Priority Areas for Surveys and Conservation Protection
Stewardship and Management Recommendations Magee and Van Clef, 2016
References Cooley, J.H. and Sambeek, J.W.V. 1990. Ulmus rubra Muhl. Slippery Elm. In: R. Burns and B. Honkala (Technical coordinators). Silvics of North America, 2. Available online at: https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_2/silvics_v2.pdf

Graney, D.L. 1990. Carya ovata (Mill.) K. Koch. Shagbark Hickory. In: R. Burns and B. Honkala (Technical coordinators). Silvics of North America, 2. Available online at: https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_2/silvics_v2.pdf

Jones, E.R. Acer barbatum Michx. Florida Maple. In: R. Burns and B. Honkala (Technical coordinators). Silvics of North America, 2. Available online at: https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_2/silvics_v2.pdf

Kennedy, H.E. 1990. Celtis laevigata Willd. Sugarberry. In: R. Burns and B. Honkala (Technical coordinators). Silvics of North America, 2. Available online at: https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_2/silvics_v2.pdf

Magee, C.S. and Van Clef, M., 2016. Plant structure of hooded and Kentucky warbler breeding sites in New Jersey. Cassinia, 76, pp.30-35. Available online at:https://dvoc.org/wp/wp-content/uploads/2018/01/Cassinia76_30_35_MageeVanClef.pdf

Smith, H.C. 1990. Carya cordiformis (Wangenh.) K. Koch. Bitternut Hickory. In: R. Burns and B. Honkala (Technical coordinators). Silvics of North America, 2. Available online at: https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_2/silvics_v2.pdf

Tymkiw, E.L., Bowman, J.L. and Shriver, W.G., 2013. The effect of white‐tailed deer density on breeding songbirds in Delaware. Wildlife Society Bulletin, 37(4), pp.714-724.

Williams, R.D. 1990. Juglans nigra L. Black Walnut. In: R. Burns and B. Honkala (Technical coordinators). Silvics of North America, 2. Available online at: https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_2/silvics_v2.pdf

Updated on 2021-12-13 11:30:36