Elk sedge has poor cover value for wild ungulates, poor to fair cover value for upland game birds, poor to good cover value for non-game upland birds, and fair to good cover value for small mammals [39]. Vegetation types with elk sedge dominating the understory often have low structural diversity and species diversity. For example, fire-maintained open ponderosa pine forests with pinegrass and elk sedge understory provide less value for pileated woodpeckers than forests developing under fire suppression because of the lack of snags housing carpenter ants for food and understory trees providing cover in the fire-maintained forests [60].
In a study of avian communities in riparian zones in Idaho, cover of elk sedge was significantly higher (p = 0.01 or p= 0.05) in plots where certain bird species were observed, including mountain chickadee, ruby-crowned kinglet, yellow-rumped warbler, western tanager, pine siskin, and dark-eyed junco [40]. In this case the bird observations may be indicating an environmental gradient, rather than preference for elk sedge, as elk sedge was less common in plots where more water-dependent bird species were observed.
Elk sedge is a native upland sedge that grows 6 to12 inches (15-50 cm) tall [69]. Elk sedge grows from branched underground rhizomes and produces an extensive network of fine roots [89,125]. A single elk sedge plant may have a root system 4.5 feet (1.4 m) wide and 6 feet (1.8 m) deep [129]. Elk sedge rhizomes grow at a depth of 0.6 to 2 inches (1.5 to 5 cm) [52,73]. Leaves and stems grow in bunch form or are more loosely clustered [45,89,130]. Leaves grow 2 or 3 to a culm [141] and are 0.04 - 0.14 inch (1-3.5 mm) wide, flat or nearly so, leathery, and evergreen [89,146].
Elk sedge is easily recognized by its few-flowered, solitary spikes. The spike has a slender staminate part bearing male flowers above the 1-3 pistillate (female) flowers, which are distinctly separate and bear scales with a short awn at the tip [89]. Each spike bears 1-3 wingless perigynia. The fruit is an achene bearing large seeds [64,69,89,141,146].
Elk sedge shoots, rhizomes, and roots. Photo ©Sierra Pacific Industires, used with permission.Fire adaptations: Elk sedge is often one of the 1st species to recolonize or grow back after a fire [23,78,119,134] because it is able to resprout from underground rhizomes [23,130] or recolonize from seeds stored in soil [124]. Elk sedge is generally slower to recover after severe burns than after lower intensity fires [13,41,139]. Fire Effects contains more detailed information about the response of elk sedge to fire.
FIRE REGIMES: Elk sedge occurs in vegetation types with a variety of FIRE REGIMES. Heyerdahl and others [67] assigned habitat types to Heinselman FIRE REGIMES in a multiscale study in the interior western United States. The habitat types or community types in which elk sedge is a codominant occur mainly within Heinselman FIRE REGIMES 2 (frequent light surface fires with 1-25 year return interval) and 3 (infrequent, severe surface fires with a greater than 25 year return interval). Elk sedge is also an important component of several types that occur within fire regime 1 (infrequent light surface fires with a greater than 25 year return interval) and 4 (short interval return crown fires with 25-100 year return intervals).
Habitat types, community types, and phases are grouped into "fire groups" for given geographic areas, based on their presettlement fire regimes, response of dominant tree species to fire, and successional patterns. The fire group assigned to a given type may vary among geographic areas because of floristic, climatic, and ecological differences among areas. The fire groups are ordered in a gradient of conditions from warmest, driest habitat types at low elevations, through cold habitat types at high elevations, to warm, moist habitat types of montane and lower elevations [124].
Elk sedge occurs as an understory dominant in warm, dry to moderate Douglas-fir forests. Generally the fire regime for these forests was characterized by frequent, nonlethal surface fire in presettlement times with relatively few stand-replacing fires [123]. Elk sedge is also listed as a component of the vegetation in types within higher elevation fire groups, including persistent lodgepole pine with a history of frequent, widespread stand-replacing fires; dry lower subalpine forests, which are characterized by a history of stand-replacing fires occurring at intervals of 52 to 200 years or more; moist lower subalpine forests that developed under less frequent and less uniform fires; and upper subalpine types with a history of mixed-severity fires with return intervals of 60 to 300 years [124]. In eastern Idaho and western Wyoming, elk sedge is a dominant species in the understory of forests developed under a wider variety of fire regimes. These forest types include certain moist Douglas-fir types with fire return intervals of 15 to 100 years and low-severity fires to severe stand replacing fires; persistent lodgepole pine community types with low-intensity ground fires or stand-replacing fires; mid- and lower elevation subalpine forests with fire return intervals of 50 to 350 years but generally greater than 100 years; and cold, upper subalpine and timberline habitat types where fires are infrequent (50-300 year return intervals) and stand-replacing fires are rare [22]. In Utah elk sedge occurs in warm, dry ponderosa pine habitat types with a history of frequent fires (less than 50 year return interval), drier Douglas-fir habitat types with a variety of FIRE REGIMES, quaking aspen habitat and community types established after fire, and habitat types with persistent lodgepole pine stands that are perpetuated or maintained by fire occurring at intervals of 22 to over 300 years [23].
Several references [1,13,59,60,126] have described elk sedge as a prominent understory component in areas with low-intensity, frequent burns. In some areas fire suppression has allowed tree canopy to increase, which has resulted in a decrease in elk sedge cover. One of the best-known examples of this phenomenon is in forests of the Blue Mountains in northeastern Oregon. These dry Douglas-fir and grand fir forests with undergrowth dominated by pinegrass and elk sedge apparently developed with a history of frequent (10-15 year return interval), low-intensity fires [1,60,126]. The open canopy and grassy understory of elk sedge and pinegrass in mixed-conifer forests of the Blue Mountains in northeastern Oregon were maintained by frequent, low-intensity fires prior to European settlement [2]. Fire suppression has led to greater canopy cover, resulting in lower understory cover, of which elk sedge is a major component [1,60]. Elk sedge is also a component of the herbaceous understory in Douglas-fir/western larch forests in the northern Rocky Mountains, which historically experienced frequent fires, and in subalpine fir forest, with long (100-300 yr) fire intervals [57]. Elk sedge also occurs in the Engelmann spruce/subalpine fir/elk sedge habitat type, in which high intensity, stand-replacing fires are common [147].
FIRE REGIMES for elk sedge sites are generally related to the dominant tree or shrub species occurring with elk sedge. The following table summarizes information about fire return intervals for the dominant species and communities with which elk sedge is found. Find further fire regime information for the plant communities in which this species may occur by entering the species name in the FEIS home page under "Find FIRE REGIMES".
Community or Ecosystem Dominant Species Fire Return Interval Range (years) grand fir Abies grandis 35-200 [11] basin big sagebrush Artemisia tridentata var. tridentata 12-43 [117] mountain big sagebrush Artemisia tridentata var. vaseyana 15-40 [12,25,100] Rocky Mountain juniper Juniperus scopulorum 106] Engelmann spruce-subalpine fir Picea engelmannii-Abies lasiocarpa 35 to > 200 [11] pinyon-juniper Pinus-Juniperus spp. 106] whitebark pine* Pinus albicaulis 50-200 [11] Rocky Mountain lodgepole pine* Pinus contorta var. latifolia 25-300+ [9,11,116] Colorado pinyon Pinus edulis 10-49 [106] Pacific ponderosa pine* Pinus ponderosa var. ponderosa 1-47 [11] interior ponderosa pine* Pinus ponderosa var. scopulorum 2-30 [11,15,91] Arizona pine Pinus ponderosa var. arizonica 2-10 [11] quaking aspen (west of the Great Plains) Populus tremuloides 7-120 [11,55,99] mountain grasslands Pseudoroegneria spicata 3-40 (10**) [9,11] Rocky Mountain Douglas-fir* Pseudotsuga menziesii var. glauca 25-100 [11] *fire return interval varies widely; trends in variation are noted in the species summaryElk sedge is common at moderate to high elevations from foothills to timberline. It occurs in dry montane forests and woodland sites, on open slopes, in drier mountain meadows and grasslands [69,74,89], and less frequently in sagebrush [76,103,149] and Gambel oak shrublands [87,150]. It grows more commonly on exposed hillsides or in open grasslands and woodlands than on more densely forested sites [93,141,148]. Elk sedge occurs primarily on well-drained sandy, gravelly, or rocky soils [141] derived from a variety of parent materials.
The following table provides a summary of the elevational ranges in which elk sedge occurs:
CO 6,000-11,000 feet [24,39,64,145] ID 1,500-9,500 feet [27,127] MT 3,400-7,900 feet [39] OR, WA 1,700-8,200 feet [58] UT 6,000-10,800 feet WY 6,800-10,000 feet [39]Elk sedge requires from 12 to 20 inches (305-508 mm) of yearly precipitation and tolerates temperatures down to -28 degrees Fahrenheit (-33 °C) [142]. However, it has been on sites with average precipitation up to 30 inches (750 mm) in Washington [20] and up to 45 inches (1,145 mm) in Oregon [32]. Heyerdahl and others [67] list elk sedge as a component of the understory in forest stands generally growing on low slope, south-west aspect sites with well-drained soils. This probably describes the majority of sites on which elk sedge grows, but site conditions vary even within the same ecosystems among different geographical areas. It may, therefore, be most helpful to describe site characteristics within the various ecosystems and areas in which elk sedge occurs.
Northern Rocky Mountain forested sites: Elk sedge is a component of the understory in several forest types of the northern Rocky Mountains. The following table provides examples of the wide variety of conditions at forested sites on which elk sedge may be found. The dominant tree species with which elk sedge grows are listed in Habitat Types And Plant Communities.
State Habitat types (HT) or dominant species Soils Parent material Aspect and other site characteristics References MT subalpine fir/elk sedge HT; Douglas-fir/elk sedge HT; whitebark pine forests; conifer/pinegrass types acidic to slightly alkaline, nongravelly loams and gravelly sandy loams to silts variety of parent materials, including calcareous sedimentary and metamorphic drier sites, south-facing and ridge top sites, mid- and upper slopes [108,132] ID Douglas-fir/elk sedge/snowberry (Symphoricarpos albus) HT; subalpine fir/elk sedge HT; whitebark pine forests; quaking aspen woods; Douglas-fir/ninebark (Physocarpus malvaceus) HT; Douglas-fir-pinegrass HT poorly-developed to deep, moderately well-drained soils; very gravelly loam soils; sandy loam soils; moraine soils wide variety of parent materials including sedimentary, granitic, metamorphic, and depositional, such as loess and volcanic ash dry, low to moderately steep slopes; drier sites in cirque basins; all aspects, depending on soils and elevation [27,34,119,127] CO montane and subalpine coniferous forest, including spruce-fir and subalpine lodgepole pine forests; lodgepole pine/elk sedge HT; quaking aspen/elk sedge HT shallow to deep soils; calcareous to otherwise basic to moderately acidic; sandy loam, loam and gravelly loam wide variety of parent materials including sedimentary, granitic, metamorphic drier south-facing slopes and open slopes; long, cool winters and cool summers [36,45,65,66,71] UT Douglas-fir/ninebark HT; white fir/ninebark HT; ponderosa pine/Gambel oak HT; quaking aspen/chokecherry (Prunus virginiana)/elk sedge type; subalpine fir/elk sedge HT; Engelmann spruce and lodgepole pine forests loamy sand and silty or sandy loam; noncalcareous soils sandstone and metamorphic parent material; Andesitic (igneous) parent material north-west to south-east facing sites; mesic, gentle slopes and benches [93,98,104,146,150] WY ponderosa pine/elk sedge HT; quaking aspen/elk sedge HT; subalpine fir/elk sedge HT; lodgepole pine/elk sedge HT moderately deep to deep moderately well-drained soils variety of parent materials relatively warm, dry, forested sites up to subalpine; variety of slopes and aspects [3,5,21,111]Intermountain forested sites: Elk sedge is an important herbaceous understory species in relatively open forested sites of the Blue Mountains of northeastern Oregon and southeastern Washington [58]. In this area, elk sedge is found on sites receiving from 8 to 45 inches (200-1,145 mm) precipitation [32]. Throughout its range, elk sedge generally grows on relatively dry sites on sandy to loamy textured well-drained soils, often derived from basalt or granite, sometimes with an ash component. At higher elevations it grows on sandy to loamy textured soils derived from basalt, granite, and tuff (compacted volcanic ash) [58]. Soils at its lower elevation range in this area are loams and silty loams derived from ash, loess, and basalt. Topik [136] lists elk sedge as an indicator of "harsh" conditions or site types on the eastern slope of the Cascade Mountains in Washington. Elk sedge was generally found in this area on fairly flat ground (2-34% slope) at 2,750 to 4,000 feet (838-1,219 m) elevation, and was associated with grand fir and pinegrass. Sites supporting the grand fir/elk sedge association were hot and dry, with cold winters and relatively short growing seasons. Elk sedge was also found in the Palouse region of southeastern Washington, predominantly on north-east-facing slopes [6]. Elk sedge may form a dense sod layer on previously-logged sites on the eastern slopes of the Cascade Mountains in west-central Washington, where precipitation averages approximately 30 inches (750 mm) per year [20].
Shrub-dominated sites: Elk sedge is less common in shrub-dominated habitat types than in forested types, but occurs over a range of conditions within shrub types. Elk sedge is a minor component of shrub-steppe habitat types in north-central Colorado. Average precipitation on these shrub-steppe sites is 14 to 15.6 inches (350-390 mm) per year, distributed fairly evenly throughout year, half occurring as snow [135]. Elk sedge occurs but is rare on dry slopes in sagebrush scrub and open woodlands in California [103]. It also occurs in sagebrush communities on south slopes in the Sawtooth Mountains of central Idaho [140] and in mountain big sagebrush (A. t. ssp. vaseyana) communities above 7,000 feet (2,130 m) on steep southeasterly slopes in the Hells Canyon National Recreation Area on the Oregon-Idaho border [76]. Elk sedge is a component of the shrub-dominated ninebark/snowberry/elk sedge community type in Umatilla River Drainage in the Blue Mountains of northeast Oregon [18]. Elk sedge has also been documented in Gambel oak shrubland in Colorado on sites with gentle (0-30%) slopes on both north and south exposures, with approximately 22 inches (560 cm) precipitation [87].
Grassland and alpine sites: Elk sedge occurs in mountain grasslands interspersed among timber stands in the Rocky Mountains. These areas are characterized by long, cold winters and relatively cool summers. Precipitation ranges from 20 to 40 inches (510-1020 mm) and occurs mostly as snow, which may cover the ground from October to May [138]. These areas have soils resembling prairie soils, with a thick A horizon rich in organic matter. Elk sedge is codominant with Idaho fescue (Festuca idahoensis) in very productive grass-sedge communities at about 7,000 feet (2,130 m) in the Seven Devils Mountains in northeast Oregon and western Idaho [76]. These grass-sedge communities occur primarily among scree slopes on the steep mountainsides. Elk sedge has also been documented on dry alpine sites in the Beartooth Mountains of south-central Montana [143].
Riparian areas: Elk sedge is an upland plant but was reported as a component of riparian vegetation at drier sites studied in the Centennial Mountains of Idaho [40].
Sources do not all agree on the value of elk sedge for livestock and wildlife forage. The forage value of elk sedge varies with conditions, but often has more to do with its availability than its palatability. Elk sedge provides valuable spring forage because it is one of the earliest forage species available on the lower ranges [141] and in dry forested sites in early spring when other palatable graminoid species and forbs are dormant [136].
The following table summarizes information presented in the literature about forage value of elk sedge for livestock and wildlife species.
Livestock or wildlife species Reported forage value and/or season of use State/vegetation types References livestock, not specified reported as relatively low OR in grand fir zone [136] livestock, not specified important, especially in spring ponderosa pine forests [43,141] cattle moderate to high, especially in spring and fall ID, OR, UT, northern Rocky Mountain States [39,72,93,109,122,129] horses good northern Rocky Mountain States [39] domestic sheep moderate general [109] bighorn sheep preferred in winter MT [115] black bears important in early spring ID [129] grizzly bears known food item general [37] deer (species not noted) low general [109] deer (species not noted) winter MT [80] mule deer important in early spring subalpine fir/beargrass habitat type [121] elk high all year general [86,109] elk important in early spring ID [92,121,129] elk heavily used early summer to fall MT [97] elk "substantial" use in winter OR [31] mountain goats spring/summer MT [118] Columbia ground squirrels eat flower parts ID, subalpine forest [90]Use of habitat types with elk sedge: Some habitat types in which elk sedge is codominant provide good forage for livestock and wildlife. The aspen/elk sedge habitat type in Colorado, the undergrowth of which is strongly dominated by elk sedge, provides fair summer-fall range for large ungulate wildlife species and cattle. Forage production in this type varies from 400 to 800 pounds per acre (450-900 kg/ha) [71]. Stands in the subalpine fir/elk sedge habitat type in Montana are used moderately by deer and elk in summer [108]. Livestock forage value in these stands is low. The Douglas-fir/elk sedge habitat type has moderate potential for forage production for livestock, and moderate to high potential for forage for wildlife where it occurs near or on winter range [83].
Use in relation to fire: There is little information available about forage use specifically of elk sedge on burned sites. According to one study conducted in the Caribou National Forest in Wyoming, elk sedge was used by elk primarily on burned sites [26]. Fire suppression has reduced the habitat suitability and use by livestock and wildlife of forest types in the Blue Mountains of eastern Oregon with elk sedge as a major understory component. For example, fire-maintained ponderosa pine/pinegrass stands produce 500 to 600 pounds per acre (540-650 kg/ha) of forage in elk sedge and pinegrass under 50% tree canopy cover. Where fire suppression has allowed fir to replace pine and the canopy cover to increase to 80%, forage production has decreased to 50 to 100 pounds per acre (55-110 kg/ha) [59].
Elk sedge is very drought-resistant [141,142] and can out-compete tree
seedlings partially through low moisture requirements [142] and early use of plant available water in soil. Elk sedge competes strongly with tree seedlings and other plants due
to its extensive rhizome and root system [128,129]. On dry forest sites elk sedge and other graminoids may
inhibit tree and shrub regeneration by depleting soil moisture before seedlings
are established [129]. On sites where elk sedge
forms a dense sod layer, elk sedge can prohibit natural
regeneration or seedling growth of conifers unless sites are scarified [20,150].
Elk sedge in ponderosa pine forest range lands is highly susceptible to
logging disturbance, such as that resulting from skidder use, because its
rhizomes are easily displaced [52]. Grass cover, of which elk sedge was a major
component, was drastically lower 1 year after logging than before logging in ponderosa
pine forests of eastern Oregon and Washington, but was restored nearly
to original levels by 7 years after logging [49]. In contrast to these reports, cover of elk sedge was lower on untreated
plots than on plots that had undergone various silvicultural treatments in the Swan Valley of
Montana [47].
The response of elk sedge to chemical site preparation treatments varies with
the compound used. Cover of elk sedge was higher in stands treated with slashing, spraying with
glyphosate, and spraying with triclopyr ester as site preparation and
conifer treatments, compared to untreated plots. The stand treated
with both glyphosate and 2,4-D had a lower canopy cover of elk sedge than the
untreated plot, but had no plant kill of elk sedge [63]. Cover of elk sedge did
not show any significant change after application of Tordon and Transline [112].
Riegel and others found that growth of elk sedge in ponderosa pine forests is
limited by nitrogen and water [113] and is controlled largely
by competition for nutrients and water by tree roots [114].
In a separate study, elk sedge growth increased after nitrogen and potassium fertilization, up to
a treatment level of 200 pounds per acre (220 kg/ha) [81].
Utilization considerations: Studies do not all agree on the effect of grazing on elk sedge forage
production. In Douglas-fir/ninebark, elk sedge cover was essentially the
same in grazed and ungrazed plots, but production in grazed plots was twice
that in ungrazed plots [152]. In contrast, elk sedge under heavy
stocking produced 74% less plant material than it did when it was protected from
grazing [50].
Overgrazing over several decades has caused understory community composition to
shift in many western forests, including a decrease in elk sedge cover as it is
replaced with more grazing-tolerant grasses. Elk sedge withstands grazing well
because it reproduces from underground rhizomes and
forms dense tufts or sod; however, continued heavy use can eventually
lower elk sedge cover [141]. Driscoll [42] found elk sedge vigor, as indicated by flowering stalk
production, was significantly lower on plants with 40% and 60% of their
herbage removed, compared to plants with 20% removed.
Because significant changes in vigor were noticeable in just 3 years, he indicated that heavy grazing over several years is
likely to reduce cover of elk sedge. Elk sedge
may be replaced by forbs and pasture grasses in some areas in the intermountain
West that have
been heavily grazed by domestic sheep in the past, and in some cases may be absent
from the understory altogether [119]. Because it often decreases under
heavy grazing pressure, elk sedge is an indicator of good range condition where it is dominant in the
understory below ponderosa pine and Douglas-fir in the Blue Mountains of
northeastern Oregon and southeastern Washington [58]. Under heavy grazing
pressure elk sedge is often replaced by pasture grasses in the Douglas-fir/ninebark
habitat type of the northern Rocky Mountains [27,28] and in quaking aspen/elk sedge sites [102].
In some cases elk sedge may respond favorably to grazing. Powell [109] stated that heavy grazing
by domestic sheep would cause an
increase in cover of elk sedge relative to the variety of palatable forbs
present in the understory of the quaking aspen/Fendler meadowrue (Thalictrum
fendleri) community type in Colorado. Zimmerman [153] found that livestock grazing had no adverse
influences on the reproduction of elk sedge, and that cover of elk sedge was the
same in grazed and ungrazed stands in the Douglas-fir/ninebark habitat type in
Idaho. However, frequency of elk sedge was slightly higher
in grazed stands.
In general, elk sedge has fair nutritional
value expressed as energy and protein.
Elk sedge
provides good food value for elk, fair food value for mule deer, fair food value
for whitetail deer, poor food value for birds, and fair to good food value for
small mammals [39]. Skovlin
[122] rated elk sedge highest for sustained nutrient supply of the forage plants
analyzed in that study.
Seasonal variation: The nutritional value of elk sedge fluctuates
seasonally, but fluctuations are less severe in elk sedge than in many other
species due to its evergreen nature. The protein content in elk sedge is
highest in spring [104,144] and declines by September. Phosphorus levels by late September were only minimally adequate
for livestock nutrition requirements, but calcium was still adequate [104]. Skovlin [122] reported that crude protein levels declined
less in elk sedge than in other species, and phosphorus and calcium levels remained fair to
good. Kreuger and Bedunah [84] found lower carbohydrate levels
in elk sedge roots in early spring than in the fall, indicating that elk sedge uses these carbohydrate reserves for respiration in
winter.
Management effects on Nutritional value of elk
sedge may be affected by grazing, silvicultural practices, and fire. In a study of
domestic sheep grazing effects on understory
species in northeastern Oregon, in vitro dry matter digestibility was higher in ungrazed
plots than on plots grazed by sheep. Light spring grazing resulted in higher crude protein content in elk sedge the
following winter [31]. According to this same study, elk sedge under a conifer
overstory had higher crude protein levels than plants of the same species
occurring in openings. Krueger and Bedunah [84] reported that total nonstructural
carbohydrate levels in elk sedge roots were higher in forested sites than in
adjacent clearcuts. Crude protein levels in elk sedge were similar between burned vs.
unburned plots in aspen stands in Wyoming [26].
Sources vary regarding the palatability of elk sedge to livestock and
wildlife. The USDA Plants Database indicates elk sedge has low palatability for browse
and forage [142]. Other sources list elk sedge as highly palatable to livestock and
moderately-highly palatable to sheep in summer [129]. The palatability rating for
elk sedge in the interior northwest is from poor to fair for sheep and from fair
to fairly good for horses and cattle, primarily due to its early sprouting in
the spring, its abundance, and its ability to remain green throughout the season. In Pacific
Northwest sites where it occurs in greater abundance,
elk sedge has a palatability rating of fair to good for sheep and from fairly
good to very good for cattle and horses [141].
Elk sedge is highly palatable to elk
[14,129] but less palatable to deer [129,141]. Austin and others [14] reported that elk sedge was highly rejected by deer. In
the Flathead National Forest of Montana, elk sedge was
highly palatable to elk relative to other species in the plant associations in
which it occurred [48]. In this case, palatability was defined by the
proportion of available forage used. Black bear
find elk sedge highly palatable in spring; palatability then declines
throughout the year [129].
Elk sedge often increases or invades after a fire [23,124,141], sometimes flowering and producing seed the year after a fire [134]. However, the ability of elk sedge to recolonize or regrow after a fire seems to depend largely on severity of the fire. Elk sedge sprouted more heavily in light surface burn areas than in severe surface burns or areas burned by crown fires in Yellowstone National Park in Wyoming [139]. According to another study in Wyoming, elk sedge cover was higher in plots after moderate burns than on unburned and severely burned plots. However, elk sedge was one of the most important postfire species in the severe burn, as well as one of the most abundant species in the moderate burn sites [41]. In central Idaho, Geier-Hayes [53] found that elk sedge cover was lower on plots clearcut and broadcast burned than on unburned clearcut plots. This effect was greatest at the highest elevation site, which also was subjected to the highest intensity burn. The ability of elk sedge to recolonize from seeds in the soil at burned sites may also be affected by fire severity. Seeds collected from burned sites in Yellowstone National Park and subjected to heat treatments survived temperatures of 212 degrees Fahrenheit (100º C) for many sites, but never survived a treatment of 302 degrees Fahrenheit (150º C). The number of seeds per area for elk sedge was generally higher in unburned vs. burn sites; survival in burned areas varied among habitat types [30].
Response of elk sedge after fire in different habitat types is dependent largely on fire severity. On a site in the dry phase of the Douglas-fir/ninebark type in western Montana, elk sedge decreased in cover 5 years after stand-replacing wildfires and clearcuts with broadcast burning. In other habitats and phases it generally increased in cover after low severity broadcast burning, clearcutting, or scarification [13]. In Douglas-fir forest in south-central Idaho, elk sedge decreased after a severe prescribed burn [96]. Elk sedge was absent from the plots 1 year after the fire, and after 7 years had grown in to roughly half its preburn cover. Elk sedge recovered quickly on recently burned areas in the Douglas-fir/elk sedge/mountain snowberry (Symphoricarpos oreophilus) type in Idaho but decreased in higher elevation sites after a severe burn [119]. Elk sedge cover and frequency decreased in burned stands in the Douglas-fir/ninebark habitat type in northern Idaho [27]. In warm, dry grand fir sites in northeastern Oregon, per cent cover of elk sedge increased within 5 years after moderate and severe burns [77]. Elk sedge cover decreased after severe burns on Douglas-fir sites in the same area, but increased after low severity burns. Arno [10] found that elk sedge cover often decreased with increasing intensity of burn in plots within shelterwood cuts in ponderosa pine forests with no-burn, low-consumption, and high consumption treatments.
Frequency of occurrence and canopy cover of elk sedge were similar on all plots in a study that compared vegetation among plots not recently burned, burned in 1932, and moderately and severely burned in 1974 in Grand Teton National Park in Wyoming [17]. In Yellowstone National Park, density of elk sedge shoots following fire was affected by patch size of burns, but this effect could be related to fire severity, as larger burned areas are more likely to have burned with more intensity [139].
Response of elk sedge to fire may be affected by competing understory species. Bunchgrasses resprouted more successfully than elk sedge when sampled 1 year after a burn in Mesa Verde National Park in Colorado [46]. Canon [26] reported that relative cover of elk sedge compared to forbs was lower on burned vs. unburned plots in aspen stands. In contrast, Johnston and Hendzel [78] found that elk sedge was able to recover quickly after fire in conifer/aspen stands in Colorado, and dominated the understory in several plots.
On ponderosa pine and Douglas-fir communities in the Blue Mountains of northeastern Oregon, elk sedge cover and frequency were higher on unburned control sites than on prescribed burned, thinned, or thinned-and-burned sites. Elk sedge was determined to be an indicator species for unburned sites (P≤0.05). For further information on the effects of thinning and burning treatments on elk sedge and 48 other species, see the Research Project Summary of Youngblood and others' [151] study.
Elk sedge regenerates primarily asexually by spreading from underground rhizomes, but also reproduces by seed [131].
Breeding system: Monoecious
Pollination: No information
Seed production: Elk sedge produces few seeds [81,142], generally 1 per flowering spike, and those produced have low viability [81,131]. Seed production often increases following disturbance [95].
Seed dispersal: Elk sedge has no apparent means for seed dispersal [129], but relies on seed stored in soil and asexual reproduction.
Seed banking: Elk sedge seeds are stored in soil [73,128]. Steele and Geyer-Hayes rated viability at 56% [128], although viability probably varies with conditions.
Germination: Seed stored in soil germinates well following clearcutting and scarification, and can also germinate on mineral soil after burning [128,129]. Seeds may not be able to germinate after being exposed to very high temperatures. In a study in Yellowstone National Park, seeds of elk sedge were collected from soil and subjected to 1-hour heat treatments of 122, 212, or 302 degrees Fahrenheit (50, 100, or 150 °C). Seeds germinated after treatments of 122 and 212 degrees Fahrenheit (50 and 100 °C) but did not germinate at 302 degrees Fahrenheit (150 °C) [30].
Seedling establishment/growth: No information
Asexual regeneration: Elk sedge spreads by short, creeping rhizomes [129,141]. Plugs have been used to propagate elk sedge where seed could not be germinated successfully [81].
Elk sedge is relatively shade-tolerant [108] compared to other upland sedges, and in some cases seems to grow more vigorously with a light canopy cover. In a study conducted in the Blue Mountains of Oregon, elk sedge growing in open areas was more stressed, with shorter, lighter green leaves drying at the tips, than plants growing under a mixed conifer overstory [31]. Other studies in the Blue Mountains reported that cover of elk sedge declines with increased tree canopy cover and poorer range condition [59,61]. Disturbance is part of the equation as well. Cholewa [27] reported that cover and frequency of elk sedge was lower in logged and grazed plots than in undisturbed climax plots. Response of elk sedge to grazing pressure is also discussed in Other Management Considerations.
The presence of elk sedge as a dominant species often indicates a late successional stage. Aspen/elk sedge and conifer/elk sedge types are generally considered stable climax types in the northern Rocky Mountains and Intermountain region of the United States [5,71,83,98,101,102,129]. For example, elk sedge is considered a late-seral to climax species in Douglas-fir habitat types of central Idaho [129]. Elk sedge also occurs as an understory codominant with pinegrass in mature stands of the Douglas-fir/ninebark/pinegrass community type, which is a theoretical climax forest in conditions of fire suppression [13]. In the Palouse region of southeastern Washington and adjacent areas of Idaho, stands dominated by elk sedge represent a topo-edaphic climax association [6]. Elk sedge is listed as an important species in climax subalpine fir and spruce eastside forests in Oregon and Washington [75].
In some site types elk sedge is considered mid-seral. For example, the presence of an elk sedge layer indicates mid-seral conditions in the subalpine fir/beargrass (Xerophyllum tenax) habitat type in northern Idaho and northwestern Montana [121]. The aspen/chokecherry/elk sedge type in Utah can be climax, or may be seral to the subalpine fir/Oregon grape (Mahonia repens) type in northern Utah or the subalpine fir/elk sedge type in southern and central Utah [104]. The aspen-lodgepole pine/elk sedge type in Idaho is seral to the lodgepole pine/pinegrass type [101].
In habitat types where elk sedge is the dominant herbaceous species, it is often 1st to sprout following fire [119]. It is also dominant in early successional stages following fire in spruce-fir forests of Colorado [29]. Elk sedge may depend on fire to lower competition from other plants. Hall [59] cited prevention of understory burning as the cause of decreased elk forage provided by pinegrass and elk sedge in mixed conifer/pinegrass communities in northeastern Oregon. Further information about the response of elk sedge to fire can be found in Plant Response To Fire.
Elk sedge has an extensive system of fine roots, making it effective at stabilizing soil [81,125,128]. However, elk sedge rhizomes may be damaged easily in scarification [73]. Elk sedge is valuable for rehabilitating disturbed sites because it can tolerate high soil moisture stress and high soil temperature [81].
Elk sedge often increases in cover after disturbance [136,153] by resprouting from rhizomes and seeding [95]. Elk sedge is highly resistant to trampling [109] and is able to increase in cover within a few years after disturbance from trampling [33]. See Fire Effects for information about the response of elk sedge after fire.
