Carex nudata Herbaceous Alliance
Torrent sedge patches
Torrent sedge patches
USDA Ecological Section Map
Summary Information
- Primary Life FormHerb
- Elevation0-1500 m
- State RarityS3
- Global RarityG3
- DistributionUSA: CA, OR, WA (TJM2)
- Endemic to CaliforniaNo
- Endemic to California Floristic Province and DesertsNo
- Date Added2009/09/01
Characteristic Species
Carex nudata is dominant in the herbaceous layer with Artemisia douglasiana, Artemisia ludoviciana, Carex praegracilis, Carex senta, Carex serratodens, Cyperus eragrostis, Darmera peltata, Datisca glomerata, Equisetum arvense, Equisetum hyemale, Mimulus guttatus, Paspalum dilatatum, Poa pratensis and Stachys stricta. Emergent riparian trees may be present at low cover, especially Alnus spp., Populus spp. or Salix spp.
Vegetation Layers
Herbs < 2 m; cover is open to continuous.
Membership Rules
- Carex nudata > 50% relative cover in the herbaceous layer; trees and shrubs < 10% cover (Potter 2005).
- Carex nudata > 50% relative cover with other herbs lower in cover including Equisetum spp. and Woodwardia fimbriata along rocky streams and streambanks (Buck-Diaz et al. 2021, Sikes et al. 2021, Sikes et al. 2023).
Habitats
Bouldery and rocky streams below the high-water mark. Soils are sandy alluvium. The USFWS Wetland Inventory (1996 national list) recognizes Carex nudata as a FACW plant.
Other Habitat, Alliance and Community Groupings
MCV (1995) | Sedge series |
NVCS (2009) | Not treated |
Calveg | Wet grasses and forbs |
Holland | White alder riparian forest |
Munz | Freshwater marsh |
WHR | Montane riparian, Valley foothill riparian |
CDFW CA Code | 45.182.00 |
National Vegetation Classification Hierarchy
Formation Class | Mesomorphic Shrub and Herb Vegetation (Shrubland and Grassland) |
Formation Subclass | Temperate and Boreal Shrubland and Grassland |
Formation | Temperate and Boreal Freshwater Marsh |
Division | Western North American Freshwater Marsh |
Macro Group | Western North America Wet Meadow and Low Shrub Carr |
Group | Californian warm temperate marsh/seep |
Remarks
Carex nudata is a robust, tufted sedge with culms to 40 cm. Spikelets vary from 2 to 6 cm in length, forming at or near the end of the culms; the tip usually has a dark-bracted staminate spikelet. Plants are typically clumped or isolated, not forming a sod. The habitat of this distinctive sedge is the bottoms and edges of cobbled and boulder-strewn streams.
The alliance occurs along perennially and seasonally flooded streams in California. Flooding from either winter or spring snowmelt creates regular mechanical impact to the boulder and cobble beds creating the characteristic substrate associated with this alliance. Highly scoured reaches of streams flowing through bedrock do not typically harbor the sedge. C. senta, another tufted streambed species, grows in similar situations. It might warrant inclusion in this alliance with further investigation. Stands are frequently associated with stands of the Alnus rhombifolia alliance and C. nudata may occur as an understory beneath open A. rhombifolia stands, depending upon flooding frequency and intensity.
The alliance occurs along perennially and seasonally flooded streams in California. Flooding from either winter or spring snowmelt creates regular mechanical impact to the boulder and cobble beds creating the characteristic substrate associated with this alliance. Highly scoured reaches of streams flowing through bedrock do not typically harbor the sedge. C. senta, another tufted streambed species, grows in similar situations. It might warrant inclusion in this alliance with further investigation. Stands are frequently associated with stands of the Alnus rhombifolia alliance and C. nudata may occur as an understory beneath open A. rhombifolia stands, depending upon flooding frequency and intensity.
Life History Traits of the Principal Species
Carex nudata | |
---|---|
Life forms | Polycarpic perennial; herb; non-rhizomatous |
Seed storage | Transient |
Seed longevity | Short |
Mode of dispersal | Gravity; water/hydrological |
Germination agents | Inundation |
Mode of sprouting | Underground structures (culms) |
Survivability after fire/disturbance | Fire-sensitive; no/low sprouter |
Disturbance-stimulated flowering | No |
Reproductive range | Life of plant |
Recruitment | High |
Regional variation | Low |
Fire Characteristics
Fluvial processes rather than fire primarily disturb the alliance. Fires in adjacent upland alliances may influence stands of Carex nudata, and off-site seed sources may establish stands after fire (Potter 2005).
Fire return interval | — |
Seasonality | — |
Size/extent | — |
Complexity | — |
Intensity | — |
Severity | — |
Type | — |
Regional knowledge | — |
Regional Status
The range of Carex nudata includes the Great Valley (262A).
- Central California Coast (261Af, Aj). Stands occur along La Honda, Pescadero, Waddell, and other larger creeks in the Santa Cruz Mountains. Stands also occur along the Big Sur River and along other streams in the Santa Lucia Mountains.
- Central California Coast Ranges (M262Ae). Stands exist along the upper Nacimiento and San Antonio rivers in the Santa Lucia Mountains.
- Klamath Mountains (M261Ac, Ai-j, Ar, Au). Stands occur along many major streams of the Klamath and Trinity rivers from low to mid elevations.
- Northern California Coast (263Af-g, Aj, Al-m). Stands exist along the Eel River, Russian River, and other major streams in the section.
- Northern California Coast Ranges (M261Ba-f). Stands occur intermittently along most of the larger, lower-order tributaries of the Eel, Mad, Russian, Van Duzen, and other rivers in the section. Stands in the Yolla Bolly Mountains occur on both sides of the Coast Range divide (Keeler-Wolf and Keeler-Wolf 1974).
- Sierra Nevada (M261Ef-g, Em, Ep). Stands occur generally in the section at lower montane elevations along many perennial streams of the western side (Potter 2005).
- Sierra Nevada Foothills (M261Fa-d). Stands along perennial streams and in wet seeps (Evens et al. 2004, Klein et al. 2007, Potter 2005) characterize the alliance.
- Southern Cascades (M261Dl). Stands at lower montane elevations contain many non-native species at low cover (S. Smith 1998b).
Management Considerations
Damming and regulation of stream flows alter the presence and distribution of this alliance throughout its range. Longer intervals between scour events may lead to the establishment of deciduous shrubs and trees, which may shade out Carex nudata stands. Extremely high and frequent flooding events eliminate the alliance from some stream reaches.
Associations
- Carex nudata [1], [2], [3], [4], [5], [6]
References
- [1] Evens, J.M.;San, S.;Taylor, J. 2004
- [2] Klein, A.;Crawford, J.;Evens, J.;Keeler-Wolf, T.;Hickson, D. 2007
- [3] Potter, D.A. 2005
- [4] Klein, A.;Keeler-Wolf, T.;Evens, J. 2015
- [5] Sikes, K.;Buck-Diaz, J.;Evens, J. 2021
- [6] Sikes, K.;Buck-Diaz, J.;Vu, S.:Evens, J. 2023
- Smith, S. 1998b