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Salix geyeriana/Carex utriculata

Geyer's willow/bladder sedge

Vegetation Composition: Salix geyeriana dominates the open overstory and characteristically appears in large, often widely-spaced clumps. Salix geyeriana can be as much as 3 m tall. A diversity of other shrubs may be present, but usually in low amounts. Some of these subordinate shrubs include Betula glandulosa, Salix boothii, Salix drummondiana, Ribes inerme, Lonicera involucrata, Potentilla fruticosa, and Alnus incana. The lower shrubs of this group often occur at the base of S. geyeriana. Carex utriculata clearly dominates the understory. Other sedges and grasses, such as Carex aquatilis, Carex interior, and Calamagrostis canadensis, may be present, but they have low cover. Forb species are sparse, but Geum macrophyllum appears to be the most constant species across the range of this type.

Classification Comments: This association has been quantitatively defined and described by at least 12 studies throughout the Intermountain region and Rocky Mountains. All these classifications have used the old name, Carex rostrata, which is now known to be strictly boreal. This name is now superseded by C. utriculata (Reznicek 1987). Because of the wide geographic distribution, different studies have taken different approaches to its classification, with some taking rather narrow approach and others taking a much broader view of this type. Most of the variability revolves around the treatment of Salix boothii, Salix drummondiana, and Carex aquatilis. Salix geyeriana and S. boothii have been treated differently in different classifications. For example, Hansen et al. (1995) in Montana include in their Salix geyeriana types those stands with all combinations of S. geyeriana and S. boothii, citing similarities between the two species in the environments they occupy and in management issues. On the other hand, Padgett et al. (1989) place stands with at least 25% cover of S. boothii into their S. boothii associations, even if the stands have greater cover of the taller S. geyeriana, arguing that that much S. boothii cover significantly alters the structure of the vegetation. Some studies have taken an even broader approach by lumping stands dominated by Salix geyeriana and S. drummondiana, as well as S. boothii, S. lemmonii, S. bebbiana, S. wolfii and/or Betula glandulosa, into a generic Salix/Carex utriculata type (e.g., Tuhy and Jensen 1982; Kovalchik 1987; Crowe and Clausnitzer 1997). Studies have also taken varying approaches to the amount of Carex aquatilis in this association. Some studies (e.g., Youngblood et al. 1985; Mutz and Queiroz 1983; Hall and Hansen 1997) take the broad view by defining a S. geyeriana/Carex utriculata type with either C. utriculata or C. aquatilis as the herbaceous dominant. A narrower approach has been taken by others (e.g., Padgett et al. 1989; Kittel et al. 1999; Walford et al. 1997), where C. utriculata is the sole herbaceous dominant and C. aquatilis-dominated sites would be a different association. The association described here is a narrow one, that is Salix boothii-dominated sites are treated as different associations (sensu Padgett et al. 1989; Walford et al. 1997; and others) and Carex aquatilis-dominated understory similarly defines a separate type (sensu Padgett et al. 1989 and others).

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Environment: Throughout its distribution, this association occurs in mountains and high valleys at elevations ranging from 4,300 to 9,000 feet. This type is most common on broad, level floodplains, but does occur in narrow bands along smaller streams in open, U-shaped valleys. Valley bottom gradients are usually low. Surface microtopography is often hummocky as a result of the irregular buildup of organic material. Hydrology of these sites is usually maintained through subirrigation and soil moisture is maintained at or near the surface in most cases. These sites may or may not be annually flooded during high water in the spring and early summer.

Soils: This association occurs on a range of soil types that are typically wet, cold, and organic or have organic surface horizons. They are generally classified as Mollisols and Histisols. Organic surface horizons, often extending to a depth of 18 inches or more, are riddled with fibrous root and plant material. Soil textures are categorized as fine, generally silts and clays. Deeper alluvial mineral deposits are comprised of coarse and fine sands and gravels. The soils are usually mottled (Hall and Hansen 1997).

Management Considerations: The wet organic soils can be strongly impacted by livestock and heavy machinery, but the dense roots and rhizomes of Carex utriculata bind the soils and stabilize the site. Loss of the shallow water table, through soil damage and/or stream incision will initially shift undergrowth composition towards drier graminoids and forbs. Willow regeneration will be limited and the mature individuals will eventually become decadent. Carex utriculata provides a very high level of streambank stabilization.

Successional Dynamics: The Salix geyeriana/Carex utriculata association is the wettest of all S. geyeriana types. Prolonged, intense utilization by livestock and wild ungulates may shift the site potential to a drier grazing disclimax, characterized by more open stands with exotic grasses, such as Poa pratensis and Agrostis stolonifera, dominating the understory. Beavers may exert a significant influence on sites as well. Active dams maintain high water tables needed to support this type. However, sustained removal of willows by beavers may reduce the site to a Carex utriculata association. When beaver abandon a site, the dams eventually deteriorate and the water table may drop, shifting the site potential to the S. geyeriana/Calamagrostis canadensis type (Hall and Hansen 1997).

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Wildlife Functions: A number of wildlife species, ranging from small mammals to rodents and songbirds, use this type for food, cover and nesting. Moose and beaver, in particular, are important in this association. Beaver may provide a vital role in the maintenance of this association in many places by maintaining high water tables (Hall and Hansen 1997).

Distribution: This is a common and widespread type in the Intermountain and Rocky Mountain areas. It is distributed from the eastern Sierra Nevada (Manning and Padgett 1995) and central Oregon (Kovalchick 1987) on the west, across northeastern Oregon (Crowe and Clausnitzer 1997), Idaho (Tuhy 1981; Tuhy and Jensen 1982; Mutz and Queiroz 1983; Youngblood et al. 1985; Jankovsky-Jones 1996; Hall and Hansen 1997), Nevada (Manning and Padgett 1995), and northern Utah (Padgett et al. 1989) to Colorado (Kittel et al. 1999), Wyoming (Norton et al. 1981; Chadde et al. 1988; Walford et al. 1997) and Montana (Hansen et al. 1995).

References:

Chadde, S. W., P. L. Hansen, and R. D. Pfister. 1988. Wetland plant communities of the northern range, Yellowstone National Park. University of Montana, School of Forestry, Missoula. 77 pp.

Crowe, E. A., and R. R. Clausnitzer. 1997. Mid-montane wetlands classification of the Malheur, Umatilla, and Wallowa-Whitman National Forests. USDA Forest Service R6-NR-ECOL-TP-22-97. Pacific Northwest Region, Portland, OR. 299 pp.

Hall, J. B. and P. L. Hansen. 1997. A preliminary riparian habitat type classification system for the Bureau of Land Management Districts in Southern and Eastern Idaho. Bureau of Land Management Technical Bulletin No. 97-11. 381 pp.

Hansen, P.L., R.D. Pfister, K. Boggs, B.J. Cook, J. Joy, and D.K. Hinckley. 1995. Classification and Management of Montana's Riparian and Wetland Sites. Montana Forest and Conservation Experiment Station, School of Forestry, Missoula, MT. 646 pp.

Jankovsky-Jones, M. 1996. Conservation strategy for Henrys Fork Basin wetlands. Conservation Data Center, Idaho Department of Fish and Game. 30 pp. plus appendices.

Kittel, G., E. VanWie, M. Damm, R. Rondeau, S. Kettler, A. McMullen, and J. Sanderson. 1999. A classification of riparian wetland plant associations of Colorado: A users guide to the classification project. Colorado Natural Heritage Program, Colorado State University, Fort Collins. 71 pp plus appendices.

Kovalchik, B. L. 1987. Riparian Zone Associations: Deschutes, Ochoco, Fremont, and Winema National Forests. USDA Forest Service, Region 6 Ecology Technical Paper 279-87. Pacific Northwest Region, Portland, OR. 171 pp.

Manning, M. E., and W. G. Padgett. 1995. Riparian community type classification for the Humboldt and Toiyabe National Forests, Nevada and eastern California. USDA Forest Service R4-ECOL-96-01. Intermountain Region, Ogden, UT. 274 pp.

Mutz, K. M., and J. Queiroz. 1983. Riparian community classification for the Centennial Mountains and South Fork Salmon River, Idaho. Meiiji Resource Consultants, Layton, UT. 170 pp.

Norton, B. E., J. Tuhy, and S. Jensen. 1981. Riparian community classification for the Greys River, Wyoming. Department of Range Science, Utah State University, Logan. 190 pp.

Padgett, W. G., A. P. Youngblood, and A. H. Winward. 1989. Riparian community type classification of Utah and southeastern Idaho. USDA Forest Service R4-ECOL-89-01. Intermountain Region, Ogden, UT. 191 pp.

Reznicek, A. A. 1987. Key to Carex rostrata complex in North America. Unpublished key. 3 pp.

Tuhy, J. S. 1981. Stream bottom community classification for the Sawtooth Valley, Idaho. Unpublished thesis, University of Idaho, Moscow. 230 pp.

Tuhy, J. S., and S. Jensen. 1982. Riparian classification for the Upper Salmon/Middle Fork Salmon River drainages, Idaho. White Horse Associates, Smithfield, UT. 183 pp.

Youngblood, A. P., and R. L. Mauk. 1985. Coniferous forest habitat types of central and southern Utah. USDA Forest Service GTR-INT-187. Intermountain Research Station, Ogden, UT. 89 pp.

Walford, G., G. Jones, W. Fertig, and K. Houston. 1997. Riparian and wetland plant community types of the Shoshone National Forest. Unpublished draft report prepared by Wyoming Natural Diversity Database, The Nature Conservancy, and the USDA Forest Service. 120 pp.

Author/Date(Update): R. K. Moseley/1998-12-04()