Carex subnigricans Herbaceous Alliance
Dark alpine sedge turf
Dark alpine sedge turf
USDA Ecological Section Map
Summary Information
- Primary Life FormHerb
- Elevation900-3200 m
- State RarityS3
- Global RarityG4
- DistributionUSA: CA, ID, NV, OR, UT, WY (USDA Plants)
- Endemic to CaliforniaNo
- Endemic to California Floristic Province and DesertsNo
- Date Added2009/09/01
Characteristic Species
Carex subnigricans is dominant or co-dominant in the herbaceous layer with Antennaria media, Calamagrostis muiriana, Calamagrostis purpurascens, Carex phaeocephala, Carex vernacula, Castilleja lemmonii, Dodecatheon alpinum, Dodecatheon redolens, Draba breweri, Draba stenoloba, Festuca brachyphylla, Gentianopsis holopetala, Luzula orestera, Luzula spicata, Mimulus primuloides, Muhlenbergia filiformis, Oreostemma alpigenum, Poa glauca ssp. rupicola, Rumex paucifolius and Sibbaldia procumbens. Emergent shrubs may be present at low cover, including Kalmia microphylla or Salix spp.
Vegetation Layers
Herbs < 30 cm; cover is continuous.
Membership Rules
- Carex subnigricans > 5% absolute cover in the herbaceous layer (Potter 2005) and usually > 50% relative cover.
Habitats
Seasonally saturated meadows, seeps and stream banks. Soils are high in organic material and may be hummocky with water tables near the surface. The USFWS Wetland Inventory (1996 national list) recognizes Carex subnigricans as a FAC plant.
Other Habitat, Alliance and Community Groupings
MCV (1995) | Sedge series |
NVCS (2009) | Not treated |
Calveg | Wet grasses and forbs, Perennial grasses and forbs |
Holland | Wet subalpine or alpine meadow, Sierra Nevada fell-field |
Munz | Alpine fell-fields |
WHR | Alpine dwarf-shrub, Wet meadow |
CDFW CA Code | 45.186.00 |
National Vegetation Classification Hierarchy
Formation Class | Mesomorphic Shrub and Herb Vegetation (Shrubland and Grassland) |
Formation Subclass | Temperate and Boreal Shrubland and Grassland |
Formation | Temperate Grassland, Meadow, and Shrubland |
Division | Vancouverian and Rocky Mountain Grassland and Shrubland |
Macro Group | Western Cordilleran montane-boreal wet meadow |
Group | Western cordilleran montane-boreal mesic wet meadow |
Remarks
Carex subnigricans is a loosely caespitose to tufted sedge with culms to 20 cm tall. It has quill-like leaves, and its flowering spike is usually one bisexual spikelet. The species ranges from California east to the Rocky Mountains.
The alliance is currently only known from subalpine and alpine elevations in California. Small stands are associated with shallow depressions in meadow systems, which tend to have higher soil moisture than sites of surrounding stands of Calamagrostis muiriana or Carex filifolia alliances. Stands of C. subnigricans often occur adjacent to wetter, summer-saturated stands of Carex (utriculata, vesicaria) and Eleocharis quinqueflora alliances, and stands may intermix with stands of Danthonia intermedia or Ptilagrostis kingii alliances in slightly drier, more elevated sections of hummocky meadows. Although some sites are permanently saturated, most are seasonally saturated.
The alliance is currently only known from subalpine and alpine elevations in California. Small stands are associated with shallow depressions in meadow systems, which tend to have higher soil moisture than sites of surrounding stands of Calamagrostis muiriana or Carex filifolia alliances. Stands of C. subnigricans often occur adjacent to wetter, summer-saturated stands of Carex (utriculata, vesicaria) and Eleocharis quinqueflora alliances, and stands may intermix with stands of Danthonia intermedia or Ptilagrostis kingii alliances in slightly drier, more elevated sections of hummocky meadows. Although some sites are permanently saturated, most are seasonally saturated.
Life History Traits of the Principal Species
Carex subnigricans | |
---|---|
Life forms | Polycarpic perennial; herb; rhizomatous |
Seed storage | Transient |
Seed longevity | Short |
Mode of dispersal | Gravity; water/hydrological |
Germination agents | Stratification—winter |
Mode of sprouting | Underground structures |
Survivability after fire/disturbance | Fire-hardy; high sprouter |
Disturbance-stimulated flowering | No |
Reproductive range | Long-lived |
Recruitment | Low; episodic |
Regional variation | Low |
Fire Characteristics
Fluvial processes rather than fire primarily disturb the alliance. Carex subnigricans sprouts after disturbance.
Fire return interval | — |
Seasonality | — |
Size/extent | — |
Complexity | — |
Intensity | — |
Severity | — |
Type | — |
Regional knowledge | — |
Regional Status
- Mono (341Dd, Dj). Stands with Carex subnigricans dominant exist at alpine elevations in the Sweetwater and White mountains (Hunter and Johnson 1983, Major and Taylor 1977).
- Sierra Nevada (M261Eh, Ej-k, En-o, Et). Stands at Harvey Monroe Hall RNA (Taylor 1984, see Cheng 2004), in Yosemite National Park (Keeler-Wolf et al. 2003b), and generally in the section (Potter 2005) occur at meadow edges and in talus that holds snow well into the summer (Potter 2005).
Management Considerations
Carex subnigricans is considered late seral with welldeveloped rhizomatous root systems according to Potter (2005). The sedge may tolerate some trampling and grazing; however, non-native plants such as Taraxacum officinale can invade stands especially with disturbance.
Associations
- Carex subnigricans - Antennaria media [1]
- Carex subnigricans - Deschampsia cespitosa [1]
- Carex subnigricans - Dodecatheon alpinum [3]
- Carex subnigricans - Oreostemma alpigenum [2]
- Carex subnigricans - Pedicularis attollens [1]
- Carex vernacula - Antennaria media [1], [3]
References
- [1] Major, J.;Taylor, D.W. 1977
- [2] Potter, D.A. 2005
- [3] Taylor, D.W. 1984
- Hunter-Bell, K.B.;Johnson, R.E. 1983