Habitats of North Carolina
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Members of General Shrublands:
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General Shrublands
General Viburnum Thickets
General Description The key factor for this habitat is the presence of Viburnum species, usually in the form of thickets but occasionally as isolated shrubs. Given the wide range of moisture, soil chemistry, elevation and temperature collectively covered by members of this genus, the Determining Species also have a wide range of environmental tolerances.

Viburnum prunifolium is the only member of its genus that is included in this habitat, since it occurs across most of the habitats occupied the other species, being rare to absent only in drier uplands. Other species of Viburnum are placed in habitats that are more specialized in terms of moisture availability and/or soil type.

Determining animal members of this habitat are mainly stenophagous herbivores of Viburnums, feeding on a number of different species within that genus and consequently occurring over a wide range of habitat types and in two or more of the state's physiographic regions. Birds and other species that make use of shrub thickets for shelter, foraging, and nesting are included in the General Shrublands and Thickets habitat.

Abiotic Factors Geographic Regions: Lower Coastal Plain to High Mountains. USDA Hardiness Zones: 6-8. Landform: ridges, slopes, bottomlands, and wet flats. Slope Aspect: occurs on all slopes aspects as well as on ridges and flats. Soil Moisture: Dry to hydric. Soil texture: sandy to loamy to alluvial. Soil pH: circumneutral to acidic. Soil Nutrient Content: rich to poor. Microclimate: Warm to cool; humid to dry. Hydrological Features: surface waters are common to scarce. Flood Frequency: permanently to never flooded. Flood Duration: nonexistent to permanent. Fire Frequency: common to rare. Drought Frequency: frequent to rare. Insolation: shaded to partially shaded; most of our native species of Viburnum occur under some form of forest or woodland

Biotic Structure Key Species species of Viburnum must be present Vegetation Type: closed-canopy forests to open woodlands. Organic Shelter, Foraging, and Nesting Structures: Viburnum thickets provide shelter, foraging, and nesting sites for many species of forest understory birds; loss of Viburnum thickets due to over-browsing by deer has tied to the loss of populations of Kentucky Warblers and Hooded Warblers in several otherwise protected natural areas.

Co-evolved Species Groups Phagic and Competitory Symbioses:
Viburnum species // Acronicta fallax-Anacampsis rhoifructella-Calledapteryx dryopterata-Glyptocera consobrinella-Metaxaglaea inulta-Schizura badia-Synanthedon fatifera-Zale horrida

Determining Species
Anacampsis consonella
Marmara viburnellaS1S30.03699
Synanthedon fatiferaLesser Viburnum Clearwing MothGNRS1S3S1S30.03699
Glyptocera consobrinellaa pyralid mothGNRS2S3S2S30.01230
Schizura badiaChestnut SchizuraG5S2S4S2S40.00407
Acleris viburnanaViburnum AclerisS3S40.00132
Anacampsis rhoifructellaGNRS3S4S3S40.00132
Acronicta fallaxGreen Marvel MothG5S4S40.00041
Calledapteryx dryopterataBrown ScoopwingG4S4S40.00041
Metaxaglaea inultaUnsated SallowGNRS4S40.00041
Zale horridaHorrid ZaleG5S4S40.00041
Viburnum prunifoliumSmooth Black-hawG5S5S50.00000
Nr = Number of Ranked Species = 11
Ner = Number of Extant, Ranked Species = 11
Nv = Number of Historic and Extirpated Species = 0
Nar = Number of Species at Risk of Extirpation (State rank > S5) = 10
Nss = Number of Secure Species (State Rank = S5) = 1
Pss = Proportion of Secure Species (Nss/Ner) = 0.09091
ENE = Expected Number of Extirpations (Sum of PE) = 0.09463
Average PE (ENE/Ner) = 0.00860
Habitat Risk Index = (Nar+Nv) x Average PE = 10 x 0.0086 = 0.086

Estimated Risk to the Determining Species Only two species in this group are ranked higher than S3 and the Average PE is equivalent to a State Rank of S3. These values indicated that this habitat has a moderate degree of conservation concern.

Estimated Risk to the Co-evolved Species Groups
Estimated Security of the Habitat Only one species in this habitat is considered secure in North Carolina and the Proportion of Secure species, at 10%, is quite low. This indicates that this habitat has become increasingly fragmented, with few, if any, large expanses or well-connected blocks of habitat.

Index of Habitat Imperilment With no Secure or Historic/Extirpated Species, the HRI value is the same as the ENE. The Average PE indicates a moderate level of conservation concern, and the relatively small number of species in this habitat produces an HRI of just 0.06, which currently (2022) falls within Tier 4 of conservation concern, i.e., again indicating a moderate priority for conservation efforts.

Identified Risks
Observed Trends
Distribution Map
Distribution Viburnum-containing habitats are found across the state; the lack of records in some counties is due to the fact that only one species of Viburnum -- V. prunifolium -- is represented on this map. The majority of the Determining Species of this habitat are insects and the highly incomplete survey coverage for that taxon explains the low number of counties showing a high percentage of representation.

Major Conservation Reserves
Priority Areas for Surveys and Conservation Protection
Stewardship and Management Recommendations
Updated on 2022-06-14 14:47:23