Carex helleri Herbaceous Alliance
Heller’s sedge fell-fields
Heller’s sedge fell-fields
USDA Ecological Section Map
Summary Information
- Primary Life FormHerb
- Elevation2400-4100 m
- State RarityS2
- Global RarityG4
- DistributionUSA: CA (NatureServe), NV? (TJM2)
- Endemic to CaliforniaNo
- Endemic to California Floristic Province and DesertsNo
- Date Added2009/09/01
Characteristic Species
Carex helleri is co-dominant or characteristically present in the herbaceous layer with Achnatherum occidentale, Agoseris glauca, Antennaria media, Arabis platysperma, Carex breweri, Carex subnigricans, Castilleja nana, Cistanthe monosperma, Draba densifolia, Elymus elymoides, Eriogonum incanum, Lupinus confertus, Luzula divaricata, Penstemon heterodoxus, Poa suksdorfii, Raillardella argentea, Saxifraga tolmiei, Silene sargentii and Trisetum spicatum.
Vegetation Layers
Herbs < 50 cm; cover is open to intermittent.
Membership Rules
- Carex helleri > 30% relative cover or conspicuous (at least 1% absolute cover) in the herbaceous layer (Keeler-Wolf et al. 2003b).
Habitats
Exposed upper slopes, ridges, snow beds. Soils are well drained gravely or sandy loams.
Other Habitat, Alliance and Community Groupings
MCV (1995) | Alpine habitat |
NVCS (2009) | Carex helleri herbaceous alliance |
Calveg | Alpine grasses and forbs, Perennial grasses and forbs |
Holland | Klamath-Cascade fell-field, Sierra Nevada fell-field, Alpine talus and scree slope |
Munz | Alpine fell-fields |
WHR | Alpine dwarf-shrub, Wet meadow |
CDFW CA Code | 45.145.00 |
National Vegetation Classification Hierarchy
Formation Class | Cryomorphic Shrub and Herb Vegetation (Polar and High Montane Vegetation) |
Formation Subclass | Temperate and Boreal Alpine Vegetation |
Formation | Alpine Scrub, Forb Meadow, and Grassland |
Division | Western North America Alpine Scrub, Forb Meadow, and Grassland |
Macro Group | Vancouverian Alpine Scrub, Forb Meadow, and Grassland |
Group | Vancouverian snowbank turf |
Remarks
Carex helleri is a densely caespitose sedge with short rhizomes and fibrous roots. Leaves are bright green and borne on the lower half of the culm, but they are not crowded toward the base. The several flower spikes are sessile and closely aggregated (Hurd et al. 1998).
Stands consist of scattered tufts of individuals in well-drained talus of cobbles and gravels. In some associations, cover in the stands is generally sparse and includes scattered individuals of other cushion plants adapted to these xeric alpine conditions. Other associations occupy snow beds in high-elevation hollows (Sawyer and Keeler-Wolf 2007).
Stands consist of scattered tufts of individuals in well-drained talus of cobbles and gravels. In some associations, cover in the stands is generally sparse and includes scattered individuals of other cushion plants adapted to these xeric alpine conditions. Other associations occupy snow beds in high-elevation hollows (Sawyer and Keeler-Wolf 2007).
Life History Traits of the Principal Species
Carex helleri | |
---|---|
Life forms | Polycarpic perennial; herb; rhizomatous |
Seed storage | Transient |
Seed longevity | Short |
Mode of dispersal | Gravity; wind |
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
Fire typically does not affect the ecology of this alliance. Probably the most important disturbance factors are freeze-thaw and drought cycles within the alpine and subalpine zones.
Fire return interval | — |
Seasonality | — |
Size/extent | — |
Complexity | — |
Intensity | — |
Severity | — |
Type | — |
Regional knowledge | — |
Regional Status
The range of Carex helleri includes the Inyo Mountains (324Fb), and Sweetwater and White mountains (341Dj, Dd).
- Sierra Nevada (M261Ek, Eo, Eq, Et). Stands from Harvey Monroe Hall RNA (Taylor 1984, see Cheng 204), Yosemite National Park (Keeler-Wolf et al. 2003b), and several locations in the section (Pemble 1970) characterize the alliance in California.
- Southern Cascades (M261Df, Dm). Stands occur on both Mount Lassen and Mount Shasta above or at timberline.
Management Considerations
Remote alpine locations generally protect Carex helleri stands from most direct human impacts. However, the stands are likely sensitive to climatic shifts, and due to their localized high-elevation, sites are likely candidates for monitoring the effects of climate change.
Associations
- Carex helleri - Arabis platysperma - Penstemon heterodoxus [2]
- Carex helleri - Eriogonum incanum - Raillardella argentea [1], [3]
- Carex helleri - Poa suksdorfii [2]
- Carex helleri - Saxifraga tolmiei - Luzula divaricata [1], [3]
References
- [1] Keeler-Wolf, T.;Schindel, M.;San, S.;Moore, P.;Hickson, D. 2003b
- [2] Pemble, R.H. 1970
- [3] Taylor, D.W. 1984
- Rundel, P.W.;Gibson, A.C.;Sharifi, M.R. 2005
- Sawyer, J.O.;Keeler-Wolf, T. 2007