Habitats of North Carolina
Habitat Group:
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Members of Upland Hardwood Forests:
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Upland Hardwood Forests
General Dry-Xeric Hardwood Forests
General Description This habitat consists of dry upland forests composed mainly of oaks, hickories, and other plant species that are tolerant of dry-to-xeric conditions, rocky or sandy soils, and occasional fires. In the Piedmont, this habitat is associated with monadnocks and other steep, and rocky ridges. In the Coastal Plain, it includes xerophytic hardwoods and shrubs found on sand ridges. In the Mountains, this habitat is widespread on south- and west-facing slopes and along rocky ridge crests.

This habitat intersects with several other much more restricted types but its Determining Species occur in at least two of the state's physiographic provinces, with some occurring in both Maritime Forests on the Barrier Islands and on well-insolated slopes in the Blue Ridge. Species of xerophytic pines and heaths have similar distributions but we include those in separate habitats.

Determining Species include the most wide-ranging, xerophytic hardwood trees in the state, as well as a few shrub and herb species that have a similar distribution. Animal species included herbivores that are specialists on the particular plant members of this habitat, as well as a few species, such as Eastern Fox Squirrel and Boll's Locust that are found primarily in dry, open hardwoods.

Abiotic Factors Geographic Regions: Lower Coastal Plain to High Mountains. USDA Hardiness Zones: 6-8. Landform: ridges and slopes. Slope Aspect: occurs primarily on south- and west-facing slopes aspects as well as on ridges. Soil Moisture: Dry to xeric. Soil texture: rocky, loamy, or sandy. Soil pH: acidic. Soil Nutrient Content: relatively poor.Microclimate: Warm to cool; dry to xeric. Hydrological Features: springs, seeps, and streams are scarce to absent. Flood Frequency: the ridges and upper slopes occupied by this habitat never flood. Fire Frequency: frequent in the sandhills, occasional in the Piedmont and Mountains. Drought Frequency: regular to occasional. Ice Storm Damage: moderate in the mountains, low elsewhere. Wind Storm Damage: moderate. Insolation: this habitat occurs primarily on very well insolated slopes and ridge tops; the canopy is typically open, allowing insolation of the lower strata

Biotic Structure Vegetation Type: open woodlands. Strata: shrub thickets may be present but herbaceous species are usually sparse. Shelter: woody debris and leaf litter are generally plentiful except where fire frequency is high

Co-evolved Species Groups Phagic and Competitory Symbioses:
Carya pallida and other xeropytic hickories // Catocala consors
Carya tomentosa // Catocala ulalume
Castanea pumila // Alebra castaneae
Robinia nana-Robinia hispida // Heliomata infulata
Quercus ilicifolia // Catocala herodias
Xerophytic Oak species // Acronicta albarufa-Cicinnus melsheimeri-Hemileuca maia-Hyparpax aurora-Hyperstrotia flaviguttata-Psaphida styracis-Erynnis brizo-Satyrium edwardsii-Satyrium favonius-Cyrtolobus inermis-Cyrtolobus ovatus-Smilia camelus

Mutualistic Symbioses:
Satyrium edwardsii // Formica integra // Smilia camelus
This group represents a multiple-symbiotic complex. Edwards Hairstreak is associated with xeric oaks that are its larval food plants, but it also requires the presence of certain species of Formica ants that tend the larvae of this butterfly in return for their production of honeydew. These same ants are often involved in a similar mutualistic relationship with the nymphs of Membracid treehoppers, particularly Smilia camelus (Weber and Nielson, 1984).

Determining Species
Ancylocera bicolorGNRS3S4S3S40.00132
Satyrium edwardsiiEdwards' HairstreakG4S2S20.03699
Satyrium favoniusOak HairstreakG4G5S3S30.00407
Satyrium calanusBanded HairstreakG5S4S5S4S50.00010
Erynnis brizoSleepy DuskywingG5S5S50.00000
Eupatorium godfreyanumGodfrey's ThoroughwortG4S3S30.00407
Hieracium venosumRattlesnake HawkweedG5S5S50.00000
Quercus prinoidesDwarf Chinquapin OakG5S1S10.33330
Quercus ilicifoliaBear OakG5S2S20.03699
Carya pallidaSand HickoryG5S4S40.00041
Castanea pumilaAllegheny ChinquapinG5S4S40.00041
Quercus coccineaScarlet OakG5S5S50.00000
Quercus marilandicaBlackjack OakG5S5S50.00000
Quercus montanaChestnut Oak, Rock Chestnut OakG5S5S50.00000
Quercus stellataPost OakG5S5S50.00000
Quercus velutinaBlack OakG5S5S50.00000
Alebra castaneaeG2G3SUS1S30.03699
Cyrtolobus inermisS3S40.00132
Cyrtolobus ovatusS3S40.00132
Smilia camelusS4S50.00010
Sciurus nigerEastern Fox SquirrelG5S3S30.00407
Catocala consorsan underwing mothG4S1S10.33330
Catocala herodiasHerodias UnderwingG3S1S10.33330
Acronicta albarufaBarrens DaggermothG3G4S1S2S1S20.11107
Stenoporpia polygrammariaFaded Gray GeometerGUS1S2S1S20.11107
Antaeotricha decorosellaGNRS2S3S2S30.01230
Heliomata infulataRare Spring MothG3G4S2S3S2S30.01230
Lytrosis permagnariaG3G4S2S3S2S30.01230
Cameraria conglomeratellaa leaf blotch miner mothGNRSUS2S40.00407
Cicinnus melsheimeriMelsheimer's Sack-bearerG4S3S30.00407
Nemoria bifilataWhite-barred Emerald MothG4S3S30.00407
Antaeotricha albulellaGNRS3S4S3S40.00132
Catocala ulalumean underwing mothG4S3S4S3S40.00132
Menesta melanellaa mothGNRS3S4S3S40.00132
Morrisonia mucensGray WoodgrainG4G5S3S4S3S40.00132
Ulolonche modestaModest Quaker MothG5S3S4S3S40.00132
Zale calycanthataDouble-banded ZaleG5S3S4S3S40.00132
Acronicta lithospilaStreaked Dagger MothG5S4S40.00041
Catocala similisSimilar UnderwingG5S4S40.00041
Hemileuca maiaBuck MothG5S4S40.00041
Hyparpax auroraPink ProminentG5S4S40.00041
Hyperstrotia flaviguttataYellow-spotted Graylet MothG4S4S40.00041
Psaphida styracisFawn SallowG5S4S40.00041
Renia fraternalisFraternal ReniaG4S4S5S4S50.00010
Melanoplus nigrescensBlack-sided Spur-throat GrasshopperGUS3S30.00407
Spharagemon bolliBoll's GrasshopperG5S4S5S4S50.00010
Robinia hispidaBristly LocustG5S4S40.00041
Robinia nanaLittle LocustG4S4S40.00041
Hypericum hypericoidesSt. Andrew's CrossG5S5S50.00000
Toxicodendron pubescensPoison Oak
Nr = Number of Ranked Species = 49
Ner = Number of Extant, Ranked Species = 49
Nv = Number of Historic and Extirpated Species = 0
Nar = Number of Species at Risk of Extirpation (State rank > S5) = 41
Nss = Number of Secure Species (State Rank = S5) = 8
Pss = Proportion of Secure Species (Nss/Ner) = 0.16327
ENE = Expected Number of Extirpations (Sum of PE) = 1.41478
Average PE (ENE/Ner) = 0.02887
Habitat Risk Index = (Nar+Nv) x Average PE = 41 x 0.02887 = 1.18367

Estimated Risk to the Determining Species This habitat has sixteen species that are ranked as S3 or higher. The Average Probability of Extirpation is equivalent to a state rank of S2 under our model.

Estimated Risk to the Co-evolved Species Groups
Estimated Security of the Habitat Eight species are considered Secure. This produces a Proportion of Secure Species of 16%, a moderately low value. Although this habitat was once widespread across the state, it was probably typically patchy outside of the Fall-line Sandhills, where large expanses of this habitat still occur. With the vast development of upland forests for human uses, however, occurrences of this habitat are now often separated from one another by miles of unsuitable habitat.

For the plant species, which include all but one of the secure species in this habitat, populations are able to persist for long periods even in fairly small, isolated patches of habitat. This is far less true for the animal species, which have only a single species in this group that is currently considered secure.

Index of Habitat Imperilment This habitat has a fairly high number -- forty -- of species at risk, which, along with a high Average Probability of Extirpation produces a correspondingly high Expected Number of Extirpations. With only a moderate number of Secure Species, the HRI value is fairly high for a habitat that is otherwise considered to be fairly common in the state. It falls within our Tier 2 (5 ≥ HRI > 0.5) level of Conservation Concern, meriting a high priority for conservation efforts.

Identified Risks As dry, upland habitats, loss and fragmentation of habitat due to development is a major threat. Suppression of wildfires in this naturally fire-prone habitat also leads to habitat loss and fragmentation. Although the hardwood trees associated with dry, rocky ridges and summits were once considered low quality in terms of their use for lumber, the development of wood-chipping as a major forest-products industry is now making increased use of these stands.

Observed Trends
Distribution Map
Distribution This habitat is widespread but the low number of counties showing appreciable concentrations of the Determining Species is characteristic of those that were naturally patchy in distribution and that have been subsequently affected by severe fragmentation due to human activities. Once these species have become extirpated from a given site, it is becoming increasingly difficult for any recovery to take place via dispersal from the next nearest sources.

Major Conservation Reserves
Priority Areas for Surveys and Conservation Protection
Stewardship and Management Recommendations
References Webster, R.P. and Nielsen, M.C., 1984. Myrmecophily in the Edward's hairstreak butterfly Satyrium edwardsii (Lycaenidae). Journal of the Lepidopterists Society, 38(2):124-133. Accessible online at: http://images.peabody.yale.edu/lepsoc/jls/1980s/1984/1984-38(2)124-Webster.pdf

Updated on 2022-06-27 23:55:55