Habitats of North Carolina
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Marshes, Mires, and Shoreline Habitats
General Sedge, Grass, and Rush Mires
General Description This habitat consists of shallow, wetlands dominated by graminoids. Ooften called beaver meadows in the past, rhey were once major features of stream and river valleys, forming hummocks and larger wet meadows as beaver ponds gradually filled in with sediments. With the near extinction of beavers across North America at the beginning of the 20th Century, these habitats became greatly reduced and fragmented. Many of their distinctive species -- most prominently, Mitchell's Satyr -- were left as rare relicts, scattered across their once vast geographic range.

The plants in this habitat grow in wet, mucky soils and experience frequent, shallow flooding. Some species, such as Carex stricta, form hummocks that rise up to a foot above the surface of the waters. Most grow in full sun but are capable of surviving in narrow galleries along streams as shrub and tree cover develop due to succession. Some are even capable of persisting for at least a while under full shade. In some areas along the lower Roanoke and other brownwater river floodplains, extensive meadows of Carex occur under a closed hardwood canopy.

The Lepidoptera belonging to this habitat all occur in association with wetland graminoids, with many known to have larvae that are obligate feeders on Carex or the other species of graminoids. The Orthoptera probably feed more generally on both sedges and wetland grasses. The one predatory member of this habitat, Libellula flavida, is associated with sedgy bogs, seeps, and beaver sedge meadows. Adults perch in open, sunny areas; larvae have also been found with the same, shallow, graminoid-choked waters.

Unlike bogs, fens, hillside seepage bogs, and sandhill seeps, all of which have significant amounts of sphagnum and thick deposits of peat, this habitat is more marsh-like in character, lacking these deposits. The openness characteristic of this habitat is maintained by frequent flooding and -- at least historically -- beaver activity, rather than occasional fire or the build up of peat too deep to allow tree growth.

Abiotic Factors Geographic Regions: High Mountins to the Lower Coastal Plain. USDA Hardiness Zones: 6-8. Landform: restricted to floodplains and wet flats. Soil Moisture: hydric. Soil Texture: mucky. Soil pH: usually acidic due to the build-up of humic acids. Soil Nutrients: generally poor with nutrient-rich examples found only in a few fens. Mucky soils are also typically anoxic. Microclimate: warm to cool, humid. Flood Frequency: several times per year to permanent. Flood Duration: weeks to months or permanent. Presence of Pools: common; both permanent and ephemeral ponds and pools may imbedded withing this habitat. Fire Frequency: uncommon in bottomlands but frequent when adjoining fire-maintained habitats. Drought Frequency: rare. Insolation: partial to full sun.

Biotic Structure Key Species species of graminoids are the dominant plant species in this habitat. Vegetation Type: herbland. Strata: canopy, subcanopy, and shrub layers are absent, although individual trees or small shrubs may be present. Organic Shelter, Foraging, and Nesting Structures: woody debris can be essentially absent; the thick growth of graminoids provides the main shelter, foraging and mating sites in this habitat; in some cases, the dead leaves of the graminoids accumulate to form hummocks that are well-elevated above the normal water levels, providing additional shelter and nesting sites.

Co-evolved Species Groups Phagic and Competitory Symbioses:
Sedge species // Amolita fessa-Amolita obliqua-Amplicephalus osborni-Cosmopterix clemensella-Deltote bellicula-Euphyes dion-Meropleon diversicolor
Carex species // Lethe appalachia-Neonympha mitchellii


Determining Species
sciNamecomNameg_ranks_rankmod_s_rankprob_of_extirpation
BUTTERFLIES
Euphyes dionDion SkipperG5S4S40.00041
Lethe appalachiaAppalachian BrownG4S4S40.00041
Ancyloxypha numitorLeast SkipperG5S5S50.00000
GRAMINOIDS
Carex lupuliformisHop-like SedgeG4S1S10.33330
Carex aureolensisGoldenfruit SedgeGNRS2S20.03699
Carex bromoidesBrome-like SedgeG5S2S20.03699
Carex canescens var. disjunctaG5T5S2S20.03699
Carex mitchellianaMitchell's SedgeG4S2S20.03699
Eleocharis quadrangulataSquarestem SpikerushG4S2S20.03699
Carex alataBroadwing SedgeG5S3S30.00407
Carex allegheniensis Allegheny SedgeGNRS3S30.00407
Carex collinsiiCollins's SedgeG4S3S30.00407
Carex festucaceaFescue SedgeG5S3S30.00407
Carex jooriiCypress-swamp SedgeG4G5S3S30.00407
Carex normalisa sedgeG5S3S30.00407
Carex prasinaDrooping SedgeG4S3S30.00407
Carex stipata var. maximaStalk-grain SedgeG5T5S3S30.00407
Carex strictaTussock SedgeG5S3S30.00407
Cladium mariscoidesTwig-rushG5S3S30.00407
Juncus canadensisCanada RushG5S3S30.00407
Juncus pylaeia rushG5S3S30.00407
Carex stipataStalk-grain SedgeG5S3S4S3S40.00132
Carex albolutescensGreenish-white SedgeG5S4S40.00041
Carex laevivaginataSmooth-sheath SedgeG5S4S40.00041
Carex scoparia Pointed Broom SedgeG5S4S40.00041
Carex stipata var. stipataStalk-grain SedgeG5T5S4S40.00041
Carex styloflexaBent SedgeG4G5S4S40.00041
Coleataenia stipitataTall Flat Panic GrassG5S4S40.00041
Schoenoplectiella purshianaWeakstalk BulrushG4G5S4S40.00041
Schoenoplectus tabernaemontaniSoftstem Bulrush, Great BulrushG5S4S40.00041
Dichanthelium lucidumBog Witch GrassG4G5S4S5S4S50.00010
Carex crinitaFringed SedgeG5S5S50.00000
Carex intumescens Bladder SedgeG5S5S50.00000
Carex longiiGreenish-white SedgeG5S5S50.00000
Carex lupulinaHop SedgeG5S5S50.00000
Carex luridaShallow SedgeG5S5S50.00000
Dulichium arundinaceumThree-way SedgeG5S5S50.00000
Glyceria striataFowl Manna-grassG5S5S50.00000
Juncus coriaceusLeathery RushG5S5S50.00000
Juncus effususCommon Rush, Soft RushG5S5S50.00000
Leersia oryzoidesRice CutgrassG5S5S50.00000
HEMIPTERAN HOPPERS
Amplicephalus osborniSNR
MOTHS
Cosmopterix clemensellaClemens' Cosmopterix MothGNRSUS2S30.01230
Bactra verutanaJavelin MothGNRSUS3S40.00132
Meropleon diversicolora noctuid mothG5S3S4S3S40.00132
Mesapamea fractilineaBroken-lined Brocade MothG5S3S4S3S40.00132
Deltote belliculaBog Lithacodia MothG5S4S40.00041
Macrochilo hypocritalisTwin-dotted Small Macrochilo MothG4S4S40.00041
Amolita obliquaOblique Grass MothG5S4S5S4S50.00010
Hypenodes fractilineaBroken-line HypenodesG4S4S5S4S50.00010
Macrochilo litophoraBrown-lined Owlet MothGNRS4S5S4S50.00010
Macrochilo orciferalisBronzy MacrochiloG5S4S5S4S50.00010
Renia sobrialisSober ReniaG5S4S5S4S50.00010
Amolita fessaFeeble Grass MothG5S5S50.00000
Rivula propinqualisSpotted Grass Moth, Yellow Snout-mothG5S5S50.00000
Bactra furfuranaGNRSUSU0.00202
ODONATES
Libellula flavidaYellow-sided SkimmerG5S4S5S4S50.00010
ORTHOPTERANS
Paroxya atlanticaAtlantic GrasshopperGUS3S4S3S40.00132
Paroxya clavuligeraOlive-green Swamp GrasshopperG5S3S4S3S40.00132
Anaxipha vernalisSpring TrigGNRS4S40.00041
Leptysma marginicollisCattail Toothpick GrasshopperG5S5S50.00000
Metaleptea brevicornisClipped-wing GrasshopperG5S5S50.00000
Nr = Number of Ranked Species = 61
Ner = Number of Extant, Ranked Species = 61
Nv = Number of Historic and Extirpated Species = 0
Nar = Number of Species at Risk of Extirpation (State rank > S5) = 46
Nss = Number of Secure Species (State Rank = S5) = 15
Pss = Proportion of Secure Species (Nss/Ner) = 0.24590
ENE = Expected Number of Extirpations (Sum of PE) = 0.59536
Average PE (ENE/Ner) = 0.00976
Habitat Risk Index = (Nar+Nv) x Average PE = 46 x 0.00976 = 0.44896

Estimated Risk to the Determining Species One sedge species in this habitat is ranked as S1 and five others are ranked as S2. The Average PE is equivalent to a State Rank of S3, indicating a moderate level of conservation concern.

Estimated Risk to the Co-evolved Species Groups
Estimated Security of the Habitat Fifteen species in this habitat are considered secure in North Carolina. The Proportion of Secure Species, however, is moderately low at 25%.

Index of Habitat Imperilment The combination of a moderately high value of ENE, a moderately low value of PSS, and no identified SH or SX species results in a moderately high value of HRI. Although not given much attention for conservation in the past, this habitat merits at least a stronger monitoring effort to determine whether it is declining or actually increasing.



Identified Risks
Observed Trends Sedge and wetland graminoid meadows may actually be increasing due the restoration of beavers to the North Carolina landscape and also to the impacts of deer grazing in the bottomlands, which may be opening up more areas for this habitat type at the expense of the thick shrub layers that once existed in our forested floodplains. In many bottomlands, now, the understory is very open and very expansive graminoid meadows are now prominent features.

Distribution Map
Distribution
Major Conservation Reserves
Priority Areas for Surveys and Conservation Protection
Stewardship and Management Recommendations
References
Updated on 2022-06-05 17:33:07