Habitats of North Carolina
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Lotic Habitats
Piedmont and General Rocky Rivers
General Description This habitat is defined by aquatic to semi-aquatic species that are associated with rivers that possess extensive areas of riffles: there must be at least a moderate current and plentiful rocks present. All species in this habitat must be able to cope with the scouring action of the rivers.

The Odonates included in this habitat perch as adults on exposed rocks located well out in the water. Foraging and mating take place in the vicinity of the riffles. Nymphs of Neurocordulia are rock-clingers (also clinging to roots and woody debris) (Tennessen, 2018) and may therefore also stick close to the riffles. So may the nymphs of the two damselflies, who live within aquatic vegetation (Schwiebert, 2007). The nymphs of the Gomphurus species, on the other hand, may reside in substrates located away from the rocks. Gomphurus nymphs are burrowers who live in substrates -- sometimes buried quite deeply -- ranging from sand, silt, gravel, and mud (Tennessen, 2018). All of these species generally require the well-oxygenated waters associated with riffle habitats and are usually found only in unpolluted rivers.

Virtually all examples of this habitat occur west of the Fall-line and include species that occur in both the Piedmont and Mountains or in the Piedmont alone. Species restricted to the cooler rivers of the mountains are treated in the Montane Rocky Rivers habitat.

Abiotic Factors
Biotic Structure
Co-evolved Species Groups
Determining Species
sciNamecomNameg_ranks_rankmod_s_rankprob_of_extirpation
FORBS
Harperella nodosa HarperellaG2S1S10.33330
Justicia americanaCommon Water-willowG5S4S5S4S50.00010
Podostemum ceratophyllumThreadfootG5S5S50.00000
GRAMINOIDS
Carex tortaTwisted SedgeG5S3S30.00407
ODONATES
Gomphurus fraternusMidland ClubtailG5S1S10.33330
Neurocordulia virginiensisCinnamon ShadowdragonG4S1S10.33330
Gomphurus lineatifronsSplendid ClubtailG4S2S20.03699
Gomphurus septimaSeptima's ClubtailG3S3S30.00407
Calopteryx angustipennisAppalachian JewelwingG4S3S4S3S40.00132
Gomphurus vastusCobra ClubtailG5S3S4S3S40.00132
Hylogomphus abbreviatusSpine-crowned ClubtailG4S3S4S3S40.00132
Hetaerina americanaAmerican RubyspotG5S5S50.00000
SNAKES
Regina septemvittataQueen SnakeG5S4S40.00041
SPIDERS
Dolomedes scriptusStriped Fishing SpiderG5S3S4S3S40.00132
TURTLES
Pseudemys concinna concinnaEastern River CooterS50.00000
Nr = Number of Ranked Species = 15
Ner = Number of Extant, Ranked Species = 15
Nv = Number of Historic and Extirpated Species = 0
Nar = Number of Species at Risk of Extirpation (State rank > S5) = 12
Nss = Number of Secure Species (State Rank = S5) = 3
Pss = Proportion of Secure Species (Nss/Ner) = 0.20000
ENE = Expected Number of Extirpations (Sum of PE) = 1.05082
Average PE (ENE/Ner) = 0.07005
Habitat Risk Index = (Nar+Nv) x Average PE = 12 x 0.07005 = 0.8406

Estimated Risk to the Determining Species
Estimated Risk to the Co-evolved Species Groups
Estimated Security of the Habitat
Index of Habitat Imperilment
Identified Risks
Observed Trends
Distribution Map
Distribution
Major Conservation Reserves
Priority Areas for Surveys and Conservation Protection
Stewardship and Management Recommendations
References Schwiebert, E., 2007. Nymphs, Stoneflies, Caddisflies, and Other Important Insects: Including The Lesser Mayflies (Vol. 2). Rowman & Littlefield.

Tennessen, K.J., 2018. Dragonfly Nymphs of North America: An Identification Guide. Springer.
Updated on 2019-09-08 18:48:50