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Carex inops

• INTRODUCTORY
• DISTRIBUTION AND OCCURRENCE
• BOTANICAL AND ECOLOGICAL CHARACTERISTICS
• FIRE EFFECTS AND MANAGEMENT
• MANAGEMENT CONSIDERATIONS
• APPENDIX: FIRE REGIME TABLE
• REFERENCES

INTRODUCTORY

AUTHORSHIP AND CITATION FEIS ABBREVIATION NRCS PLANT CODE COMMON NAMES TAXONOMY SYNONYMS LIFE FORM FEDERAL LEGAL STATUS OTHER STATUS
	Typical subspecies on a disturbed Siskiyou County, CA, site. Photo by Dr. Dean Wm. Taylor, Jepson Herbarium.

Carex inops subsp. heliophila, sun sedge [37,63]
Carex inops subsp. inops (Mackenzie) Crins, typical subspecies of long-stolon sedge [54]

These subspecies are poorly differentiated, both morphologically and taxonomically [26,37] (see General Botanical Characteristics). In this review, the subspecies are referred to as "sun sedge" and the "typical subspecies". "Long-stolon sedge" refers to the species as whole. As of 2009, most literature pertained only to sun sedge.

In the broad sense, long-stolon sedge is a member of the Pennsylvania sedge (C. pennsylvanica) complex [26,93], a group of closely related taxa characterized by rhizomes or long stolons [16,26].

DISTRIBUTION AND OCCURRENCE

• GENERAL DISTRIBUTION
• HABITAT TYPES AND PLANT COMMUNITIES

Subspecies:
Sun sedge occurs from north-central British Columbia east to southeastern Ontario and south to southern New Mexico and northwestern Indiana. It is most common east of the Rocky Mountains.

The typical subspecies occurs on the West Coast. It is patchily distributed from south-central British Columbia to north-central California [26,37,104,108].

• Sun sedge
• Typical subspecies

Sun sedge is occasional [60] to dominant [22] in mid- to high-elevation (>5,000 feet (2,000 m)) mountain meadows [22,60] and shrublands of the northern Rocky Mountains. It showed high constancy (75%) but not dominance in Rocky Mountain juniper/bluebunch wheatgrass (Juniperus scopulorum/Pseudoroegneria spicata) draws in the Dakotas regions of the Missouri Plateau [50] and had minor coverage in Wyoming big sagebrush/Idaho fescue (Artemisia tridentata subsp. wyomingensis/Festuca idahoensis) habitat types of north-central Colorado [111].

Vegetation classifications describing plant communities where sun sedge is a dominant or indicator species are listed below by state and province.

• codominant to dominant in mid- to high-elevation (>5,000 feet (2,000 m)), wet to dry sedge (Carex sp.) mountain meadows [22]
• dominant in mixed-grassland xerophytic associations on mesas, foothills, and in montane zones [89,90]
• interior ponderosa pine/sun sedge community types in the Black Forest; these community types are extensions of Rocky Mountain interior ponderosa pine types that finger into the Great Plains [71]
• interior ponderosa pine/sun sedge and interior ponderosa pine-Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca)/sun sedge communities of the Front Range [64]
• Parry's oatgrass (Danthonia parryi)/sun sedge habitat type; this type forms park openings in interior ponderosa pine forests on the northern Front Range [111]
• blue grama-sun sedge and western wheatgrass-sun sedge shortgrass prairie communities of northeastern Colorado [80]

• interior ponderosa pine/sun sedge woodland; ranked rare and local (G3) by The Nature Conservancy [97]
• interior ponderosa pine-Rocky Mountain juniper/sun sedge plant association of the Charles M. Russell National Wildlife Refuge [20]
• interior ponderosa pine/sun sedge forest habitat type of the Custer National Forest [49]
• needle-and-thread grass-sun sedge, Idaho fescue-sun sedge, prairie sandreed-sun sedge, and bluebunch wheatgrass-sun sedge steppe habitat types of the Custer National Forest [49]
• creeping juniper (Juniperus horizontalis)/sun sedge shrub-steppe habitat type of the Custer National Forest [49]
• silver sagebrush (Artemisia cana)/sun sedge, sand big bluestem-sun sedge, prairie sandreed-sun sedge, little bluestem-sun sedge, and Idaho fescue-sun sedge alliances; all ranked G3 by The Nature Conservancy [97]
• prairie sandreed-needle-and-thread grass-sun sedge associations on sandy rangelands [94]

• interior ponderosa pine/blue grama-sun sedge woodlands on Pine Ridge escarpments of Sioux, Dawes, and Sheridan counties [107]
• ponderosa pine/blue grama-sun sedge woodlands of the Niobrara Valley Preserve [53]

• rough fescue-sun sedge association of north-central North Dakota [21]
• blue grama-needle-and-thread grass-sun sedge habitat type of the Sheyenne National Grassland [77]
• blue grama-needle-and-thread grass-sun sedge and blue grama-sun sedge-little bluestem communities of the Central Grasslands Research Station; the former is the most common community type in the area [73,75]
• sand big bluestem-sun sedge alliance; ranked G3 by The Nature Conservancy [97]

• interior ponderosa pine/bur oak (Quercus macrocarpa)/sun sedge and interior ponderosa pine/sun sedge habitat types of the Black Hills [56]

• needle-and-thread grass/sun sedge and Idaho fescue/sun sedge habitat types on the Custer National Forest; these form a mosaic with interior ponderosa pine parklands [48,49]
• interior ponderosa pine/sun sedge woodland; ranked G3 by The Nature Conservancy [97]
• interior ponderosa pine/sun sedge habitat type of the Black Hills and Bearlodge Mountains of eastern Wyoming [1]
• codominant to dominant in mid- to high-elevation (>5,000 feet (2,000 m)) wet to dry sedge (Carex sp.) mountain meadows [22]

• indicator species of the shortbristle needle-and-thread (Hesperostipa curtiseta) plains grassland vegetation type [72]
• prairie sandreed-sun sedge alliance; ranked G3 by The Nature Conservancy [97]
• creeping juniper/sun sedge and sun sedge blowout (wind-eroded) duneland communities in the southern part of the province [58]

BOTANICAL AND ECOLOGICAL CHARACTERISTICS

GENERAL BOTANICAL CHARACTERISTICS SEASONAL DEVELOPMENT REGENERATION PROCESSES SITE CHARACTERISTICS SUCCESSIONAL STATUS   GENERAL BOTANICAL CHARACTERISTICS: Botanical description Raunkiaer life form
	Long-stolon sedge flowerhead. © 2008 Keir Morse.

Aboveground: Long-stolon sedge is a loosely caespitose, perennial graminoid [37,52]. It is low to medium statured compared to other Carex [17,60]. Culms are 4 to 20 inches (10-50 cm) long [37,54]. Leaves are slender, stiff, and wiry [103]. Old, dead leaves are persistent [37,44], often forming fibrous tufts at the stem base [37,44,103]. Inflorescences are terminal staminate and pistillate spikes [37,44,46]. Male spikes may be pediceled above female spikes. The fruit is a hairy [103] achene [26,37,44,46] ranging from 1.6 to 2.5 mm long [26]. Seedheads bear 5 to 15 fruits each [103].

Belowground: Long-stolon sedge typically has well-developed rhizomes [37,68]. Its common name is a misnomer; only one flora describes long-stolon sedge as stoloniferous [44]. Sun sedge's rhizomes are slender [52,60] and coarse [60], varying in length from "short" [46] to "long" [44,46]. The California flora describes the typical variety as "long-rhizomed" [54]. Depth of long-stolon sedge rhizomes was not documented in the literature as of 2009.

Long-stolon sedge has fibrous roots. Sun sedge has shallow [112,113], coarse, primary and secondary fibrous roots [60]. Using a model, Peters and Herrick [87] predicted sun sedge's depth of maximum root biomass in desert grasslands as 12 inches (30 cm) [45].

Life span: A model predicted sun sedge's maximum life span in desert grasslands at 25 years [45].

The typical variety of long-stolon sedge fruits from late April to late July across its distribution [37].

• Vegetative regeneration
• Pollination
• Seed production, dispersal, banking, and germination
• Seedling establishment and plant growth

Vegetative regeneration: Sun sedge sprouts from the rhizomes after top-kill [18,20]. Top-killed plants likely also sprout from their root crowns.

Pollination: Long-stolon sedge is wind pollinated [104].

Seed production, dispersal, banking, and germination: No information was available on these topics.

Seedling establishment and plant growth: Little is known of either sun sedge's ability to establish from seed or its growth rate.

Heavy grazing usually limits sun sedge's growth. In a blue grama-buffalo grass mixed grassland of Wind Cave National Park, South Dakota, sun sedge reached greatest average height (3 inches (8 cm)) on ungrazed plots. Mean height decreased with increasing levels of black-tailed prairie dog grazing. Lowest mean height (2 inches (4 cm)) occurred on 4- to 6-year-old prairie dog towns, which were the oldest prairie dog towns surveyed [5]. See Other Management Considerations for further information on grazing impacts.

Sun sedge's predicted maximum growth rate in desert grasslands is probably slow relative to that of associated species. A model predicted a maximum biomass of 0.2 ounce (7.2 g)/plant [45].

• Sun sedge
• Typical subspecies

Preferred sun sedge soils are mesic and well drained, although sun sedge grows on dry sites in the Intermountain West. Sun sedge is more common on mesic than droughty soils on the Great Plains [59]. In blue grama-buffalo grass associations of Alberta and Saskatchewan, sun sedge is most abundant on "favored", mesic sites such as sandy swales [25]. On the Custer National Forest, the needle-and-thread grass/sun sedge habitat type occurs on soils that are typically wetter than soils of the needle-and-thread grass/threadleaf sedge (Carex filifolia) habitat type [49]. Sun sedge grows in dry forest habitats. On the Charles M. Russell National Wildlife Refuge, it is an associated species in the interior ponderosa pine/bluebunch wheatgrass type, which occurs on south-facing slopes with dry, coarse soils [20].

Topography: Sun sedge may be more abundant on sheltered than exposed sites. On the Charles M. Russell National Wildlife Refuge, interior ponderosa pine-Rocky Mountain juniper/sun sedge communities generally occur on mesic, north- or east-facing slopes [20]. Sun sedge and Schweinitz's flatsedge (Cyperus schwenitzii) were the most frequent of 21 associated taxa in sand big bluestem rolling prairies of eastern Nebraska. The sedges were common on all aspects but were most frequent between dunes [96]:

On the Konza Prairie Natural Research Area of Kansas, sun sedge was more common on upland than lowland big bluestem communities [41].

Elevation: Few elevational ranges were reported for sun sedge as of 2009. It occurs from 5,000 to 9,000 feet (2,000-3,000 m) in Colorado [52,71]. It was collected from 4,501 to 5,171 (1,372-1,576 m) in the Black Hills and Bear Lodge Mountains of Wyoming [56].

Climate: Sun sedge may not tolerate extended drought. Sarvis [95] reported that in the Northern Great Plains, the "Dust Bowl" drought of 1934 to 1936 reduced sun sedge from predrought dominance to "near elimination", with sun sedge confined to depressions and ravines in 1938 surveys.

Typical subspecies:
Soils: The typical subspecies grows on well-drained, sandy and loamy soils on open slopes [26,37]. It occurs on dry, rocky soils in California [54].

Elevation: Across its distribution, the typical subspecies occurs from 330 to 7,000 feet (100-2,000 m) [37,54]. It is reported from 3,000 to 7,000 feet (1,000-2,000 m) in California [54] and from 4,902 to 5,121 (1,494-1,561 m) on the slopes of Mt Hood [105].

• Sun sedge
• Typical subspecies

Short- and mixed-grass prairies: Sun sedge is a common species in seral plains grassland communities. In a 1919 Colorado survey, sun sedge dominated early-seral, mixed-grass prairies on dry mesas and foothills [89]. In mixed-grass dunelands of southern Saskatchewan, sun sedge is codominant to dominant on blowout depressions; blowout communities are typically a midsuccessional stage of duneland succession. Needle-and-thread grass-fringed sagebrush (Artemisia frigida) communities are the final stage of duneland stabilization; sun sedge is typically important but no longer dominant in stabilized duneland communities [58].

Animal disturbance: Sun sedge occurs on both grazed and ungrazed grasslands across its range [37]. Sun sedge was most frequent in new black-tailed prairie dog colonies in mixed-grass prairie habitats of Wind Cave National Park [4,5]. Sun sedge cover (and frequency) averaged 0% (0%) on uncolonized plots; 5% (71%) on plots colonized 2 to 3 years; and 2% (58%) on plots colonized 4 to 6 years [5]. In a blue grama shortgrass prairie on the Central Plains Experimental Range, Colorado, sun sedge was significantly denser and had more cover on western harvester ant mounds than sites without ant disturbance (P<0.05) [16].

Heavy livestock grazing usually lowers sun sedge abundance. See Other Management Considerations for further information.

Although common in seral plains grasslands, sun sedge typically persists and may be important to dominant in late-seral plains grasslands. In a chronosequence study of old fields on the Pawnee National Grassland and the Central Plains Experimental Range of Colorado, sun sedge was codominant on 25- to 50-year-old fields. By then, the fields had converted to blue grama-buffalo grass shortgrass communities [18]. On the Custer National Forest, the needle-and-thread grass/sun sedge and Idaho fescue/sun sedge habitat types are climax stages of shortgrass prairie steppe vegetation. With disturbance, sagebrush (Artemisia spp.) and nonnative grasses, especially Kentucky bluegrass (Poa pratensis) and Japanese brome (Bromus japonicus), become more important in the needle-and-thread/sun sedge type. The Idaho fescue/sun sedge type is drier, and nonnatives are less likely to invade on disturbed Idaho fescue/sun sedge sites, although sagebrush may be invasive [49].

Tallgrass prairies: Sun sedge is generally more abundant in early- than late-successional tallgrass prairies. For example, it was more important in seral than climax sand bluestem-prairie sandreed (Calamovilfa longifolia)-little bluestem prairies of the Nebraska sandhills [24]. Ina 1938 survey of sandhill vegetation in Cherry County, Nebraska, sun sedge was an important groundlayer component of blowout grass (Redfieldia flexuosa) communities, the earliest successional phase in development of sand bluestem prairies [106]. In big bluestem-sideoats grama-little bluestem prairie of Nebraska, sun sedge was more common on open sites than beneath eastern redcedar (Juniperus virginiana) canopies [100].

Woodland and forest succession: Sun sedge is most common on open sites in woody plant communities, although it may grow in shade on harsh sites. In Rocky Mountain National Park, Colorado, sun sedge frequency was significantly higher on trail edges than in interior coniferous forests (P=0.238) [11]. In a chronosequence study of old fields in the Black Forest of eastern Colorado, sun sedge was an important understory species of 22-year-old fields. Interior ponderosa pine saplings dominated the old field overstory. Blue grama dominated the understory, with sun sedge the eventual groundlayer dominant (see Colorado plant communities). Interior ponderosa pine seedlings and invasive nonnatives such as sixweeks grass (Vulpia octoflora) dominated younger old fields [71]. In ponderosa pine woodlands of the Niobrara Valley Preserve, sun sedge increased in importance with increasing stand density [53]. Sun sedge may benefit from shade protection on these xeric sites (see Site Characteristics).

Mycorrhizal associations may favor other herbs over sun sedge on some sites. On the Colorado State Forest, sun sedge dominated the ground layer beneath mountain pine beetle-killed interior ponderosa pines (7.3% cover) but not beneath live interior ponderosa pines (1.5% cover). Laboratory examinations for vesicular-arbuscular mycorrhizae in groundlayer plant species found no evidence of mycorrhizal infection in sun sedge. The authors speculated that under live trees—where infected groundlayer species dominated—groundlayer species with vesicular-arbuscular mycorrhizae associations outcompeted sun sedge for water, phosphorus, and/or micronutrients [65].

FIRE EFFECTS AND MANAGEMENT

• FIRE EFFECTS
• FUELS AND FIRE REGIMES
• FIRE MANAGEMENT CONSIDERATIONS

• Immediate fire effect on plant
• Postfire regeneration strategy
• Fire adaptations and plant response to fire

Severe fire can kill sun sedge on some sites. On the Charles M. Russell National Wildlife Refuge, a mixed-severity wildfire burned through an interior ponderosa pine-Rocky Mountain juniper/sun sedge woodland and a Rocky Mountain juniper shrubland. An unpublished report documented that fire severity was generally lower in the ponderosa pine woodland than in the shrubland. In the woodland, sun sedge mortality was "highly variable", ranging from 0% to 100% based on comparison of sun sedge cover on burned and unburned plots in postfire year 4. Sun sedge was present on some severely burned patches in the ponderosa pine woodland at postfire year 4, suggesting top-kill, but did not occur on severely burned shrubland sites. The authors speculated that the high prevalence of low-growing Rocky Mountain junipers in the shrubland resulted in a greater downward heat pulse when the shrubland burned than occurred when the ponderosa pine woodland burned [20]. Hotter soil temperatures on the shrubland sites might have killed sun sedge rhizomes.

Information on the fire ecology of the typical subspecies was lacking as of 2009, and research is needed in this area. Given the subspecies' morphological and taxonomic similarities, fire effects and plant responses to fire are probably similar for sun sedge and the typical subspecies.

Fire adaptations and plant response to fire:
Fire adaptations: Soil protects sun sedge's rhizomes from fire on many sites [17,20]. Establishment from dispersed or soil-stored seed may be important after severe fires and on sites where sun sedge was absent before fire; however, information on sun sedge's ability to establish from seed after fire was lacking as of 2009.

Plant response to fire: Sun sedge sprouts from the rhizomes after top-kill by fire [17,20]. Sprouting from the root crown is also likely, although this was not documented in the literature. Sun sedge responses after tallgrass prairie, shrubland, and woodland fires are detailed below. Its rate of recovery after short- and mixed-grass prairie fires was not available as of 2009.

Prescribed fires favored sun sedge in a plains rough fescue prairie near Saskatoon, Saskatchewan. Fires were set in spring (6 May 1998), summer (26 June 1998), and fall (8 October 1998). In the 2nd postfire growing season, sun sedge cover was greater on all burned plots than on an adjacent unburned plot, with greatest cover on fall-burned plots [6].

See the Research Project Summary of this study for information on the fire prescription, fire behavior, and postfire responses of 33 other plant species in the plains rough fescue community.

On a quaking aspen-rough fescue parkland in east-central Alberta, annual burning may have favored sun sedge by creating drier site conditions than are typical for these parklands. Anderson and Bailey [2,3] reported a "major increase" in sun sedge cover and frequency after 25 years of repeated annual April burning. At that time, cover and frequency of sun sedge were significantly greater (P<0.005) on burned plots than on unburned plots [2,3]. Overall, annual spring burning decreased plant productivity [3] but favored graminoids and forbs over woody species [2,3].

Shrubland and woodland communities: In the short term, sun sedge grew slowly after the stand-replacement Chapin 5 Wildfire in Mesa Verde National Park, Colorado. Prefire frequency of sun sedge was not known, but sun sedge was not present on study plots at the end of the 1st postfire growing season [39]. At the end of the 2nd postfire growing season, sun sedge had similar frequency in Colorado pinyon-Utah juniper (Pinus edulis-Juniperus osteosperma) woodland (0.06%), shrubland dominated by bitterbrush (Purshia tridentata) and/or Gambel oak (Quercus gambelii) (0.07%), and Colorado pinyon-Utah juniper/shrubland (0.05%) communities [38,39].

After wildfire on the Charles M. Russell National Wildlife Refuge (see Immediate fire effect on plant), sun sedge cover in interior ponderosa pine woodland ranged from 0% to 30%. Sun sedge recovery was apparently inversely related to postfire cover of Japanese brome. In the shrubland, sun sedge postfire cover on moderately-burned sites ranged from 4% to 20% in postfire year 4 [20].

• Fuels
• Fire regimes

Fire regimes: Historically, the grassland and woodland communities in which sun sedge is common had fire-return intervals of 20 years or less. Across the Great Plains, grassland fires may have occurred as frequently as every 1 to 6 years [66]. Frequent fires in tallgrass prairies helped maintain these grasslands [29]. Interior ponderosa pine/sun sedge woodlands experienced mostly frequent, low-severity understory fires with occasional stand-replacing fires [20]. See the Fire Regime Table for further information on fire regimes of vegetation communities in which sun sedge and the typical subspecies may occur. 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".

Sun sedge is an important forage plant (see Importance to Wildlife and Livestock), and fire-grazing interactions probably influence sun sedge's ability to recover from fire. No research was available on the interactive effects of grazing and fire on sun sedge as of 2009. Since sun sedge cannot tolerate heavy grazing even without fire, heavy postfire utilization of sun sedge would probably result in sun sedge decline.

MANAGEMENT CONSIDERATIONS

• IMPORTANCE TO WILDLIFE AND LIVESTOCK
• VALUE FOR REHABILITATION OF DISTURBED SITES
• OTHER USES
• OTHER MANAGEMENT CONSIDERATIONS

Sun sedge is considered "excellent feed" for cattle and other livestock. Early spring green-up provides important early forage [59,95,103], and cattle usually graze sun sedge heavily in early spring [22,95]. Livestock utilization may extend through the growing season [95]. On the Manitou Experimental Forest, Colorado, cattle grazed sun sedge lightly in all months except November, when utilization increased to 1.4% of the diet. Mule deer also grazed sun sedge year-round, with use peaking in May (7.6% of diet). The rangeland was an interior ponderosa pine/sleepygrass (Achnatherum robustum) type [27].

Palatability and/or nutritional value:
Mammals: Sun sedge is moderately to highly palatable to cattle [31,62,110] and highly palatable to horses [31]. It is rated fairly palatable to domestic sheep, pronghorn, and mule deer and unpalatable to white-tailed deer [31]. Surveys on the Northern Great Plains showed a mean overall grazing utilization of 80% [95]. On an interior ponderosa pine/Arizona fescue rangeland [61] and an interior ponderosa pine/little bluestem-Arizona fescue rangeland on the Manitou Experimental Forest, Colorado, cattle grazed sun sedge more than expected based on its availability. On the Manitou Experimental Forest, sun sedge usage increased greatly and cover slightly with level of grazing intensity, with 12% use and 2% cover on lightly grazed and 42% use and 6% cover on heavily grazed plots [99]. Higher use under heavy grazing suggests that other, more palatable graminoids were depleted first.

For most mammalian grazers, palatability of sun sedge likely decreases through the grazing season. On sand big bluestem-little bluestem sandhills prairie of Nebraska, cattle utilization of sedges (Carex, with sun sedge most common) was greatest in May (22%), when sun sedge production peaked at 96 kg/ha [61]. On plains grasslands of North Dakota, palatability of sun sedge for cattle was high early in the growing season and low late in the growing season [57]. In blue grama-cheatgrass and western wheatgrass-Japanese brome grasslands of north-central Colorado, desert cottontails grazed sun sedge heavily in spring (49% frequency) and lightly in summer (3% frequency) [30].

Insects: Conflicting field and laboratory results leave sun sedge's relative palatability for grasshoppers undetermined to date (2009). In a blue grama-prairie sandreed community of northeastern Colorado, 5 species of grasshopper preferred bunchgrasses to sun sedge; sun sedge use was light (<3%) [51]. In the laboratory, high levels of phenolics were detected in sun sedge relative to associated grasses, and grasshoppers (Ageneotettix decorum and Phoetaliotes nebracensis) preferred grasses over sun sedge. Plant materials and grasshoppers were collected in a big bluestem-little bluestem-western wheatgrass sandhills prairie community on the Arapaho Prairie, Nebraska [83]. However, in a sand bluestem-little bluestem-sun sedge community on the Arapaho Prairie, sun sedge had lower levels of phenolics than sand bluestem and little bluestem, suggesting it was more palatable than those grasses. Differences were significant for plant species and across years within species (P=0.001). Within years, sun sedge's phenolic content increased from late May to September [82].

On the Central Grasslands Research Station in south-central North Dakota, preference of scarab beetle (Phyllophaga anxia) grubs for needleleaf sedge (Carex duriuscula) and western wheatgrass over sun sedge and blue grama increased the relative densities of sun sedge and blue grama in a mixed-grass prairie infested with grubs [74].

Nutritional value: See Hopper and Nesbitt [57] for a nutritional analysis of sun sedge in the seed stage.

Cover value: Sun sedge may provide important habitat and cover for greater prairie-chickens. Of 11 habitat types on the Sheyenne National Grasslands of North Dakota, blue grama-needle-and-thread grass-sun sedge hummocky sandhills were the most important nesting and brooding habitats of greater prairie-chickens. The blue grama-needle-and-thread grass-sun sedge habitat type was also important for roosting. Most greater prairie-chicken night roosts—primarily willows (Salix sp.) and cottonwoods (Populus sp.)—were located within the habitat type [77].

Sun sedge "stood up well" under grazing and clipping treatments in the Northern Great Plains [95]. Moir and Trlica [80] concluded that 30 years of moderate cattle grazing on blue grama-western wheatgrass-sun sedge communities of southeastern Colorado had little effect on plant species composition, including sun sedge abundance, and that "this is not unexpected, since shortgrass prairies of North America have a long history of coevolution with grazing animals". Sun sedge showed no significant change in biomass 4 years after cessation of cattle grazing on a hairy grama-prairie sandreed-big bluestem community of the Arapaho Prairie [88], suggesting tolerance of prior grazing. On the Sheyenne National Grasslands, there was no significant difference in sun sedge basal cover among ungrazed, season-long, and grazing-deferred plots. Stocking rates were provided [77].

Grazing may favor sun sedge on some sites. On western wheatgrass-prairie Junegrass-needle-and-thread grass rangeland in North Dakota, sun sedge cover increased progressively on ungrazed (19%), season-long grazed (20%), and rotation-grazed (24%) plots. Stocking rate was 10 cow-calf pairs/32 ha [12]. In Wind Cave National Park, sun sedge cover increased in black-tailed prairie dogs towns under heavy grazing pressure for at least 3 years after black-tailed prairie dog colonization, while cover of associated—and likely more palatable—Kentucky bluegrass and needle-and-thread grass decreased [4].

A few studies found sun sedge decline with heavy use. In a blue grama-needle-and-thread-threadleaf sedge (Carex filifolia) mixed grassland in North Dakota, sun sedge was more common on exclosures than on sites with cattle grazing (0.5% vs. 0.1%, respectively). Total graminoid utilization was approximately 40% on grazed sites [13]. In the Little Missouri Badlands of North Dakota, overall sun sedge cover was lower on grazed than ungrazed plots but differed among sites. The blue grama-needle-and-thread grass-threadleaf sedge community showed greatest differences in sun sedge production between ungrazed and grazed plots [14]:

APPENDIX: FIRE REGIME TABLE

• Sun sedge
• Typical subspecies

Carex inops: REFERENCES

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2. Anderson, Howard A. 1978. Annual burning and vegetation in the aspen parkland of east central Alberta. In: Dube, D. E., compiler. Fire ecology in resource management: Workshop proceedings; 1977 December 6-7; [Edmonton, AB]. Information Report NOR-X-210. Edmonton, AB: Environment Canada, Canadian Forestry Service, Northern Forest Research Centre: 2-3. Abstract. [317]

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4. Archer, Steve; Garrett, M. G.; Detling, James K. 1987. Rates of vegetation change associated with prairie dog (Cynomys ludovicianus) grazing in North American mixed-grass prairie. Vegetatio. 72: 159-166. [2864]

5. Archer, Steven R. 1983. Plant community structure, competitive interactions and water relations as influenced by herbivores. Fort Collins, CO: Colorado State University. 114 p. Dissertation. [338]

6. Archibold, O. W.; Ripley, E. A.; Delanoy, L. 2003. Effects of season of burning on the microenvironment of fescue prairie in central Saskatchewan. Canadian Field Naturalist. 117(2): 257-266. [48371]

7. Barbour, Michael G.; Billings, William Dwight, eds. 1988. North American terrestrial vegetation. Cambridge; New York: Cambridge University Press. 434 p. [13876]

8. Barker, William T.; Whitman, Warren C. 1994. SRM 606: Wheatgrass - bluestem - needlegrass. In: Shiflet, Thomas N., ed. Rangeland cover types of the United States. Denver, CO: Society for Range Management: 75. [67061]

9. Barker, William T.; Whitman, Warren C. 1994. SRM 607: Wheatgrass - needlegrass. In: Shiflet, Thomas N., ed. Rangeland cover types of the United States. Denver, CO: Society for Range Management: 76-77. [67062]

10. Becker, Donald A.; Bragg, Thomas B.; Sutherland, David M. 1986. Vegetation survey and prairie management plan for Pipestone National Monument. Report prepared for U.S. Department of the Interior, National Park Service, Pipestone National Monument; Contract No. CX-6000-2-0076. Elkhorn, NE: Ecosystems Management. 126 p. [60514]

11. Benninger-Truax, Mary; Vankat, John L.; Schaefer, Robert L. 1992. Trail corridors as habitat and conduits for movement of plant species in Rocky Mountain National Park, Colorado, USA. Landscape Ecology. 6(4): 269-278. [22175]

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13. Brand, Michael D. 1980. Secondary succession in the mixed grass prairie of southwestern North Dakota. Fargo, ND: North Dakota State University. 77 p. Dissertation. [14147]

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