Habitats of North Carolina
Habitat Group:
Habitat Type:
Members of Marshes, Mires, and Shoreline Habitats:
« »
Marshes, Mires, and Shoreline Habitats
General Cattail and Tall Grass Marshes
General Description This habitat represents the classic freshwater marsh, composed of tall, emergent, narrow-bladed herbaceous species that are rooted in the mucky soils of seasonally to permanently flooded wetlands. This habitat was probably originally associated primarily with beaver ponds and would have been widespread, common, and with very extensive occurrences prior to the great extirpation of beavers that reached its peak 100 years ago. Following the demise of its natural wetlands, this habitat survived in farm ponds and other artificial wetlands; today, it is a common feature of stormwater detention ponds.

This habitat occurs across the state, with species that are more restricted included in regionally-specialized versions. Cattail and tall Grass Marshes co-occur with Willows and other woody species, but those are treated as a separate habitat, Shoreline Shrublands. Sedge meadows and other low-herbaceous mires are also treated separately as are Beaver Ponds themselves.

The Determining Species of this habitat are those that occur widely in freshwater marshes: those that found in at least two of the physiographic provinces of the state. This group includes all the species that occur in the Piedmont, but excludes species associated with freshwater marshes that are restricted to the Coastal Plain or the Mountains. In addition to wide-ranging marsh plants, the Determining Species include both specialist herbivores associated with those plants, as well as others, such as the bird species, that use these marshes for foraging, shelter, and nesting.

Abiotic Factors Geographic Regions: High Mountins to the Lower Coastal Plain. USDA Hardiness Zones: 6-8. Landform: floodplains and wet flats. Soil Moisture: wet to hydric. Soil Texture: alluvial to mucky. Soil pH: acidic to circumneutral. Soil Nutrients: poor to rich. Microclimate: warm to cool; generally humid. Flood Frequency: several times per year to permanent. Flood Duration: short term to permanent. Fire Frequency: uncommon. Insolation: full sun

Biotic Structure Vegetation Type: open herbland. Organic Shelter, Foraging, and Nesting Structures: the dense, tall vegetation of this habitat itself provides key shelter, foraging, and nesting sites for all of the animal species of this habitat.

Co-evolved Species Groups Phagic and Competitory Symbioses:
Typha species // Bellura obliqua-Capsula oblonga-Chionodes rabula-Dicymolomia julianalis-Limnaecia phragmitella
Erianthus gigantea // Meropleon cosmion

Determining Species
Ixobrychus exilisLeast BitternG5S2S3S2S30.01230
Rallus elegansKing RailG4S3S30.00407
Agelaius phoeniceusRed-winged BlackbirdG5S5S50.00000
Typha latifoliaBroad-leaf CattailG5S5S50.00000
Scirpus georgianusGeorgia BulrushG5S2S20.03699
Zizaniopsis miliaceaSouthern WildriceG5S3S30.00407
Erianthus giganteusSugarcane Plume Grass, Giant Plume GrassG5S4S40.00041
Scirpus cyperinusCottongrass BulrushG5S5S50.00000
Meropleon cosmionSeaside Goldenrod Borer MothG4S3S4S3S40.00132
Capsula oblongaOblong Sedge BorerG5S3S5S3S50.00041
Chionodes rabulaGNRS3S5S3S50.00041
Limnaecia phragmitellaShy Cosmet MothGNRS3S5S3S50.00041
Bellura obliquaCattail Borer MothG5S4S5S4S50.00010
Dicymolomia julianalisJulia's Dicymolomia MothGNRS4S5S4S50.00010
Nr = Number of Ranked Species = 14
Ner = Number of Extant, Ranked Species = 14
Nv = Number of Historic and Extirpated Species = 0
Nar = Number of Species at Risk of Extirpation (State rank > S5) = 11
Nss = Number of Secure Species (State Rank = S5) = 3
Pss = Proportion of Secure Species (Nss/Ner) = 0.21429
ENE = Expected Number of Extirpations (Sum of PE) = 0.06059
Average PE (ENE/Ner) = 0.00433
Habitat Risk Index = (Nar+Nv) x Average PE = 11 x 0.00433 = 0.04763

Estimated Risk to the Determining Species The Average Probability of Extirpation for the species belonging to this habitat is equivalent under our model to a state rank of S3. That indicates that this habitat meets the minimal requirement for conservation concern.

Estimated Risk to the Co-evolved Species Groups The Average Probability of Extirpation for the eight species involved in the co-evolved species groups is 0.000625, which under our model is equivalent to a state rank of S4. That is lower than for the habitat as a whole, which is due to the rarer species -- e.g., Least Bittern and Georgia Bulrush -- being left out of any identified co-evolved complex.

Estimated Security of the Habitat Three of the Determining Species are considered secure in the state: Broad-leaf Cattail, Cottongrass Bulrush, and Red-winged Blackbird. All three species are highly dispersive and can colonize even small areas of wetland habitats, for example storm-water detention ponds. Prior to the extirpation of beavers from most of their range, these habitats would have been found in nearly all watersheds within the state. Following that extirpation, however, these habitats would have become greatly reduced in size and highly fragmented. As with other species associated with beaver-created habitats, some of these species became quite rare and are now only beginning to reclaim their former range.

Index of Habitat Imperilment The fairly low Average PE and the relatively small number of Determining Species results in a relatively low Expected Number of Extirpations. Coupled with the moderately low value -- 21% -- for the Proportion of Secure Species, the HRI value is correspondingly low, falling within our Tier 4 of Conservation Concern (0.05 ≥ HRI > 0.005), reflecting a low priority for conservation efforts. With beaver now having spread across the state and forming extensive pond complexes in a number of watersheds, this is one of the few natural habitats in the state that is becoming more secure rather than less.

Identified Risks In the past, over-harvest of beaver for the fur trade led to the near-extinction of this species, along with many of the species associated with beaver-created habitats. While the demand for beaver pelts has greatly declined, the ponds created by beavers and their cutting of timber for food is not welcomed by many landowners, with the consequence that dams are destroyed in many areas and beaver killed as pests.

In addition to direct persecution by humans, runoff of pollutant- and sediment-laden waters from adjoining agricultural, silvicultural, or developed areas adversely affects the water quality in the wetlands occupied by this habitat. Spraying Glyphosates to maintain powerlines and other open rights-of-way may also be preventing the formation of cattail marshes in these areas: this herbicide is widely used to control cattail populations in residential lakes and ponds where they are considered aesthetically undesirable or impede fishing or other recreational activities (Sojda et al., 1993).

Observed Trends Beavers were extirpated from the state by 1920, leading to a vast reduction in natural marshland habitats, with only some replacement due to the creation of farm ponds. Following the re-introduction of beavers beginning in the late 1940s and 1950s, these habitats have expanded and are now found in most of the watersheds in the state. The construction of storm-water detention ponds -- mimics of natural beaver ponds -- have added still more areas that are now occupied by Cattails and other tall marsh graminoids.

Distribution Map
Distribution Cattail and bulrush marshes are found across the state, although they are most abundant in the wetlands of the Coastal Plain. Counties showing a high proportion of the Determining Species are those where moth sampling has been conducted in this habitat type.

Major Conservation Reserves
Priority Areas for Surveys and Conservation Protection
Stewardship and Management Recommendations
References Sojda, R.S. and Solberg, K.L. 1993. Management and Control of Cattails. In: USFWS. Waterfowl Management Handbook. Available online at: https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1032&context=icwdmwfm
Updated on 2023-01-24 21:38:29