Habitats of North Carolina
Habitat Group:
Habitat Type:
   
Members of General Shrublands:
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General Shrublands
General Greenbrier Tangles
General Description The presence of Greenbriers (Smilax species) is the key factor for this habitat. Most members of this genus are found in forests and woodlands, ranging from moist to dry, but several also occur out in open shrublands, including maritime scrub on the Barrier Islands. Although this habitat matches a number of the same factors as the General Forests and Shrublands habitat, it is unclear how closely it matches the extent occupied by the various types of shrublands across the state. Greenbrier tangles are also very distinctive and have a set of specialized herbivores that help set them apart. For the time being, we treat them as a separate habitat but one that closely intersects the General Forests and Shrublands.

The Determining Species of this habitat include insect herbivores that are stenophagous on Greenbriers and generally occur wherever members of that genus are found in the state. Saw Greenbrier (Smilax bona-nox) is also included since its range encompasses most of the range of the entire genus. Other species of Greenbrier, however, are more restricted in their distributions and are placed in other habitats.

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: all types from 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: varies from permanently flooded to never flooded. Flood Duration: nonexistent to permanent. Fire Frequency: common to rare. Drought Frequency: frequent to rare. Ice Storm Damage: low to severe. Wind Storm Damage: low. Insolation: full sun to full shade

Biotic Structure Key Species: species of Smilax must be present.Vegetation Type: closed-canopy forest to shrublands that completely lack a forest canopy. Strata: shrub layers are often well developed, providing a substrate for the growth of Greenbrier vines. Shelter: Woody debris and leaf litter are plentiful to sparse

Co-evolved Species Groups Phagic and Competitory Symbioses:
Smilax species // Acrolepiopsis heppneri-Acrolepiopsis incertella-Marmara smilacisella-Phosphila miselioides-Phosphila turbulenta-Phyprosopus callitrichoides-Proleucoptera smilaciella-Pseudogalleria inimicella

Host // Commensal Symbioses:
Mimicry Complexes:

The larvae of Phyprosopus callitrichoides are excellent mimics of their host plants, bearing filaments that closely resemble the tendrils used by Smilax to climb up shrubs and trees
(host-specific lichens and bryophytes)
(host specific decomposers)

Mutualist // Mutualist Symbioses:
(mycorrhizal assocations)
(Pollinator Associations)
(Host/Disperser Associations)

Competitor Guilds:

Determining Species
sciNamecomNameg_ranks_rankmod_s_rankprob_of_extirpation
MOTHS
Acrolepiopsis heppneriGNRS2S3S2S30.01230
Acrolepiopsis incertellaCarrionflower MothGNRS2S3S2S30.01230
Proleucoptera smilaciellaa mothGNRS3S4S3S40.00132
Pseudogalleria inimicellaInimical Borer MothGNRS3S4S3S40.00132
Marmara smilacisellaa leaf blotch miner mothGNRSUS4S50.00010
Phosphila miselioidesSpotted PhosphilaG5S5S50.00000
Phosphila turbulentaTurbulent PhosphilaG5S5S50.00000
Phyprosopus callitrichoidesCurved-Lined OwletG5S5S50.00000
VINES
Smilax bona-noxSaw GreenbrierG5S5S50.00000
Nr = Number of Ranked Species = 9
Ner = Number of Extant, Ranked Species = 9
Nv = Number of Historic and Extirpated Species = 0
Nar = Number of Species at Risk of Extirpation (State rank > S5) = 5
Nss = Number of Secure Species (State Rank = S5) = 4
Pss = Proportion of Secure Species (Nss/Ner) = 0.44444
ENE = Expected Number of Extirpations (Sum of PE) = 0.02734
Average PE (ENE/Ner) = 0.00304
Habitat Risk Index = (Nar+Nv) x Average PE = 5 x 0.00304 = 0.0152

Estimated Risk to the Determining Species None of the species of this habitat are ranked as S1 or S2. The Average PE is equivalent to a State Rank of S3, indicating only a moderate level of conservation concern.
Estimated Risk to the Co-evolved Species Groups
Estimated Security of the Habitat Four species are considered secure in North Carolina and the Proportion of Secure Species is 44%, a moderately high value. This habitat is still widespread and occurs either in large or in well-connected blocks of habitat.

Index of Habitat Imperilment The combination of a low value of ENE, a high value of PSS, and no identified Historic or Extirpated Species, makes the value of HRI quite low. This habitat, consequently, is not a high conservation priority.

Identified Risks
Observed Trends
Distribution Map
Distribution
Major Conservation Reserves
Priority Areas for Surveys and Conservation Protection
Stewardship and Management Recommendations
References
Updated on 2022-06-04 19:16:47