Habitats of North Carolina
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General Hardwood Forests
General Elm Forests
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General Description The key environmental factor for this habitat is the presence of Elm (Ulmus) species. Forests containing one of our three Elms -- American, Slippery, and Winged -- range the from bottomlands where American Elms occur, to rich, mesic slopes, where Slippery Elms are found, to dry to wet forests where Winged Elms range.

Of our three species of Elms, only Winged Elm spans the entire range of habitats occupied by this genus in North Carolina and is considered a Determining Species of this habitat; American and Slippery Elms are included instead as Determining Species in their more specialized habitats. Other Species that are placed in this habitat appear to use all species of Elms and occur over the entire range of habitats spanned by the Elm species.

Abiotic Factors Geographic Regions: Lower Coastal Plain to the Low Mountains. USDA Hardiness Zones: 6-8. Landform: ridges, slopes, bottomlands, wet flats, and swamps. Slope Aspect: north, east, south, and west, also flat. Soil Moisture: Dry to hydric. Soil texture: loamy, silty,or mucky. Soil pH: acdic to circumneutral. Soil Nutrient Content: rich for most terrestrial sites to poor in blackwater swamps. Microclimate: cool to warm; dry to humid. Hydrological Features: streamheads on ridges and slopes, swamps in Outer Coastal Plain. Flood Frequency: essentially never flooded on ridges to permanently flooded in swamps. Flood Duration: nonexistent to permanent. Fire Frequency: uncommon on ridges, rare in swamps. Drought Frequency: uncommon in uplands, rare in swamp forests. Ice Storm Damage: high in the mountains, low in the Outer Coastal Plain. Wind Storm Damage: moderate. Insolation: canopies are well insolated, lower strata are deeply shaded.

Biotic Structure Key Species: Elms must be present.Vegetation Type: Closed-canopy forests composed of broadleaf, deciduous trees; Winged Elm also occurs in young successional stands of hardwoods Strata Subcanopy, shrub, and herb-layers well-developed and often lush. Organic Shelter, Foraging, and Nesting Structures: woody debris and leaf litter are plentiful except in flood channels or other areas frequently scoured by floods.

Co-evolved Species Groups Phagic and Competitory Symbioses:
Ulmus species // Cameraria ulmella-Ectoedemia ulmella-Phyllonorycter argentinotella-Phyllonorycter occitanica-Stigmella apicialbella-Colopha ulmicola

Determining Species
Colopha ulmicolaElm Cockscomb AphidSNR
Saperda tridentataElm BorerS3S40.00132
Ulmus alataWinged ElmG5S5S50.00000
Agromyza aristataElm Agromyzid LeafminerS3S40.00132
Aceria campestricolaa mite
Phyllonorycter occitanicaGNRS3S5S3S50.00041
Cameraria ulmellaGNRSUSU0.00202
Ectoedemia ulmellaGNRSUSU0.00202
Phyllonorycter argentinotellaGNRSUSU0.00202
Stigmella apicialbellaGNRSUSU0.00202
Nr = Number of Ranked Species = 8
Ner = Number of Extant, Ranked Species = 8
Nv = Number of Historic and Extirpated Species = 0
Nar = Number of Species at Risk of Extirpation (State rank > S5) = 7
Nss = Number of Secure Species (State Rank = S5) = 1
Pss = Proportion of Secure Species (Nss/Ner) = 0.12500
ENE = Expected Number of Extirpations (Sum of PE) = 0.01113
Average PE (ENE/Ner) = 0.00139
Habitat Risk Index = (Nar+Nv) x Average PE = 7 x 0.00139 = 0.00973

Estimated Risk to the Determining Species The Average PE is equivalent to a State Rank of S3 but many of the species in this habitat are still unranked. Generally, the association with most of these species with Winged Elm, a common, widespread, euryoecious species, gives this habitat a relatively high degree of security.
Estimated Risk to the Co-evolved Species Groups
Estimated Security of the Habitat Winged Elm is considered secure in the state and most of the species associated with it will probably be eventually determined to be nearly as common.

Index of Habitat Imperilment The combination of a low value of both ENE and PSS and a lack of historic/extirpated species produces a low value of HRI, falling within our Tier 4 (0.05 ≥ HRI > 0.005) Level of Conservation Concern, indicating a low priority for conservation actions.

Identified Risks
Observed Trends
Distribution Map
Distribution The distribution of this habitat, as mapped above, largely reflects the records for Winged Elm, the only well-surveyed species in this habitat. The concentration in Wake and Durham Counties is due to a concentration of survey efforts in those counties for the leaf-mining species that make up the majority of species in this habitat.

Major Conservation Reserves
Priority Areas for Surveys and Conservation Protection
Stewardship and Management Recommendations
Updated on 2022-07-12 21:04:00