Index of Species Information

SPECIES:  Eriophorum vaginatum


SPECIES: Eriophorum vaginatum
AUTHORSHIP AND CITATION : Howard, Janet L. 1993. Eriophorum vaginatum. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: [].

ABBREVIATION : ERIVAG SYNONYMS : Eriophorum spissum Fern. Eriophorum callitrix Cham. SCS PLANT CODE : ERVA4 COMMON NAMES : sheathed cottonsedge tussock cottongrass cottonsedge cottongrass hare's tail hare's-tail grass TAXONOMY : The currently accepted scientific name of sheathed cottonsedge is Eriophorum vaginatum L. (Cyperaceae). Recognized North American subspecies are as follows [2,25,19,40]: Eriophorum vaginatum L. ssp. vaginatum Eriophorum vaginatum L. ssp. spissum (Fern.) Hult. LIFE FORM : Graminoid FEDERAL LEGAL STATUS : No special status OTHER STATUS : NO-ENTRY


SPECIES: Eriophorum vaginatum
GENERAL DISTRIBUTION : Sheathed cottonsedge has a circumboreal distribution.  In North America, it is distributed from Alaska east to Labrador and south to Minnesota, Wisconsin, Indiana, and Pennsylvania.  Eriophorum vaginatum ssp. spissum occurs throughout this range.  The typical subspecies is primarily distributed in Eurasia but overlaps with E. v. ssp. spissum in Alaska and Alberta [2,19,25,40,47]. ECOSYSTEMS :    FRES10  White - red - jack pine    FRES11  Spruce - fir STATES :      CT  IN  ME  MA  MI  MS  NH  NJ  NY  OH      PA  RI  VT  WI  AB  BC  MB  NF  NT  NS      ON  PE  PQ  SK  YT BLM PHYSIOGRAPHIC REGIONS : NO-ENTRY KUCHLER PLANT ASSOCIATIONS :    K094  Conifer bog    K095  Great Lakes pine forest SAF COVER TYPES :     12  Black spruce     13  Black spruce - tamarack     21  Eastern white pine     38  Tamarack    204  Black spruce SRM (RANGELAND) COVER TYPES : NO-ENTRY HABITAT TYPES AND PLANT COMMUNITIES : Sheathed cottonsedge-dominated tussock tundra vegetation types are extensive in interior Alaska; they are the most widespread types north of the Brooks Range.  Sheathed cottonsedge vegetation types include sheathed cottonsedge-ericaceous shrub, sheathed cottonsedge-willow, and sheathed cottonsedge-mixed shrub [37,57].  Dryness and Grigal [9] list a black spruce (Picea mariana)/sheathed cottonsedge woodland type also occurring in interior Alaska.  Pure stands of sheathed cottonsedge are relatively rare, although a few exist on arctic slopes.  Sheathed cottonsedge is sometimes an understory species in Sitka alder (Alnus viridis ssp. sinuata) communities [37,57]. Sheathed cottonsedge tussock tundra occurs at high elevations in the Great Lakes and New England states.  Sheathed cottonsedge also grows in open conifer swamps dominated by black spruce and/or tamarack (Larix laricina) in the Lake States [33,60]. Publications listing sheathed cottonsedge as a dominant or indicator species are as follows: Vegetation types in northwestern Alaska and comparisons with    communities in other Arctic regions [21] Reconnaissance of vegetation and soils along the Dempster Highway,    Yukon Territory:  I. Vegetation types [50]. A preliminary classification system for vegetation of Alaska [57] The Alaska vegetation classification [58] Shrub associates of sheathed cottonsedge in interior Alaska include bog labrador tea (Ledum palustre), bog blueberry (Vaccinium uliginosum), dwarf arctic birch (Betula nana), cloudberry (Rubus chamaemorus), leatherleaf (Chamaedaphne calyculata), greyleaf willow (Salix glauca ssp. acutifolia), and diamondleaf willow (S. planifolia ssp. pulchra). Ground cover associates include Bigelow sedge (Carex bigelowii), Carex lugens, mosses (Polytrichum juniperinum and Aulacomnium turgidum), and lichens (Cetraria nivalis, C. cucullata, Cladonia gracilis, and C. mitis) [2]. Sheathed cottonsedge associates in the Lake States include leatherleaf, bog rosemary (Andromeda glaucophylla), bog birch (Betula pumila), bog laurel (Kalmia polifolia), few-seeded sedge (Carex oligosperma), and sphagnum mosses [60].


SPECIES: Eriophorum vaginatum
IMPORTANCE TO LIVESTOCK AND WILDLIFE : Sheathed cottonsedge is grazed by sheep, cattle, lemmings, ground squirrels, caribou, and geese [6,20,64].  Caribou graze it year-round; it may form a considerable portion of their diet in some areas [1]. Following a mid-summer fire, Klein [28,29] found that fall-migrating caribou of the Western Arctic Herd near Kotzebue Sound of Alaska preferentially grazed postfire growth of sheathed cottonsedge.  Its early spring growth makes it important early-season forage for caribou on calving grounds [65].  Willow ptarmigan eat sheathed cottonsedge flower buds [43]. Open muskeg-sheathed cottonsedge tussock areas in the Lake States are preferred habitat of sharp-tailed grouse.  Waterfowl use these areas as breeding grounds [60]. PALATABILITY : NO-ENTRY NUTRITIONAL VALUE : The nutritional value (dry-matter basis) of sheathed cottonsedge collected in August from the Reindeer Preserve near Inuvik, Northwest Territories, was 10.3 percent protein, 1.3 percent crude fat, and 33.8 percent fiber [48]. COVER VALUE : NO-ENTRY VALUE FOR REHABILITATION OF DISTURBED SITES : Sheathed cottonsedge has potential for restoration of disturbed sites because of its success as a colonizer [64].  It was one one the first species to colonize areas of the northeastern United States and southeastern Canada that were mined for peat [12].  It also colonized denuded areas of an oil well site in Oumalik, Alaska [10].  Seed collection, storage, and germination information is available [64]. Sheathed cottonsedge was top-killed by an experimental oil spill in the MacKenzie Delta of Alaska but grew back from rootstocks the following year [3]. OTHER USES AND VALUES : NO-ENTRY OTHER MANAGEMENT CONSIDERATIONS : Rangeland:  Sheathed cottonsedge recovers rapidly following occasional defoliation by herbivores.  Tieszen and Archer [54] found that new leaves of defoliated plants grew at faster rates than those of intact plants.  When defoliated plants were subjected to a second defoliation treatment, however, growth was markedly depressed from that of control plants.  Overstocked reindeer have greatly reduced sheathed cottonsedge in Canada's Reindeer Grazing Preserve [64]. Heavy sheep grazing on a sheathed cottonsedge-Scotch heather (Calluna vulgaris) bog in northern England resulted in complete dominance of the community by sheathed cottonsedge [23].  Continued heavy sheep grazing, however, has resulted in sheathed cottonsedge decline or death [64]. Soil:  The phosphatase activity of sheathed cottonsedge roots adds phosphorus to nutrient-poor arctic soils [39].


SPECIES: Eriophorum vaginatum
GENERAL BOTANICAL CHARACTERISTICS : Sheathed cottonsedge is a native, tussock-forming graminoid. Its culm varies from 8 to 28 inches (20-70 cm) in length and is sheathed to half its length.  The acaulescent leaves and scales are tightly compacted. Sheathed cottonsedge foliage dies back each winter, but basal portions of leaves and stems remain green [14].  The inflorescence is a densely tufted cyme composed of multiflowered spikelets.  The fruit is an achene [25,19].  Roots are densely fibrous and die back to rootstocks each winter [36,35,39].  The roots hydrolyze and absorb organic phosphorus compounds from the soil, providing up to 69 percent of the plant's phosphorus requirement [31,39].  Sheathed cottonsedge does not form mycorrhizal associations [6]. Sheathed cottonsedge tussocks are composed of 300 to 600 individual tillers [14].  They are elevated above ground level.  Tussocks near Toolik Lake, Alaska, averaged 8 inches (20 cm) in diameter.  Measuring from tiller bases, they also averaged 8 inches above ground.  Roots averaged 12 inches (30 cm) in length, extending 4 inches (10 cm) below ground until reaching the permafrost layer [39].  Individual tillers live less than 8 years; estimated age of mature tussocks ranges from 122 to 187 years [36]. RAUNKIAER LIFE FORM :       Chamaephyte REGENERATION PROCESSES : Sheathed cottonsedge reproduces sexually by seed and vegetatively by tillering [2,18].  Seeds are first produced at age 3 and are dispersed by wind [56].  Flower and seed production increase with disturbance [5]. Sheathed cottonsedge often dominates northern seedbanks:  97 percent of seed found at a site on Kuparuk Ridge of the Brooks Range was sheathed cottonsedge and Bigelow sedge [17].  Peat-buried sheathed cottonsedge seeds remain viable for long periods of time in cold arctic environments.  Longevity of seed collected from peatbeds near Eagle Creek, Alaska, was estimated to be at least 200 years [38].  Sheathed cottonsedge seeds readily germinate after overwintering when exposed to light and warm temperatures [18].  Live mosses or liverworts, dead leaves, and dead peat are favorable seedbeds.  Seedling establishment is best on disturbed sites; it is rare in mature tussock communities [37]. Seedling growth rate is largely controlled by nutrient availability and is most rapid after fire has released nutrients into the soil [7]. Tallis [53] found that tussocks increase in number during dry years, probably because of drought intolerance of Bigelow sedge seedlings. Sheathed cottonsedge produces tillers at the rate of one to three per year, with tillering increasing in response to disturbance.  Tillers die after flowering but decompose slowly due to compaction and low temperature [14,15]. SITE CHARACTERISTICS : Sheathed cottonsedge occurs in a continental climate with extreme seasonal variations in temperature [4].  It grows on plateaus and gently sloping foothills of interior Alaska and alpine areas of the northeastern United States [30].  It is found in tundra bogs, muskegs, and pockets of boreal forest [36,62].  In the Adirondack Mountains, it occurs at elevations of 500 to 1,500 feet (1,600-5,000 m) [33].  In Alaska, it occurs at 3,600 to 9,800 feet (1,100-3,000 m) [9]. Parent materials of sheathed cottonsedge-supporting soils include polymictic conglomerate, lithic wacke, siltstone, and shale overlain by frozen glacial till and sand or sandy loam.  Depth of thaw into mineral soil is 2 to 4 inches (5-10 cm).  Soils belong to the Inceptisol order. Mineral soil is usually covered by an up to 16-inch-thick (40 cm) horizon of poorly decomposed peat [2,17,26,59].  The superficial surface layer may be a hepatic, moss, or lichen mat [17].  Soils are well to poorly drained, low in nutrients, and acidic [2,39,56].  Soil pH ranges from 3.0 to 5.1 in Yukon Territory and the Northwest Territories [50]. SUCCESSIONAL STATUS : Obligate Initial Community Species Sheathed cottonsedge colonizes disturbed sites including burns, frost boils, and gravel pits [8,24,27,56].  It increased in importance wherever disturbance occurred in Yukon Territory [63].  Sheathed cottonsedge tussock communities are stable for many decades, but are eventually replaced in the absence of disturbance.  Sheathed cottonsedge is replaced by Carex species near Fairbanks, Alaska, and by Scotch heather on the Seward Peninsula [4,26].  It is sometimes replaced by black spruce below the northern tree limit [29].  In the Lake States, it is replaced by tamarack (Larix laricina) and red pine (Pinus resinosa) [60]. SEASONAL DEVELOPMENT : Sheathed cottonsedge flower buds are formed the year prior to flowering [8].  Sheathed cottonsedge begins growth earlier in spring than most tundra plant species [35].  Early growth is rapid, with new root tissue initiated first.  Kummero and others [34] reported that new root growth began prior to snowmelt (early June) in the northern foothills of the Brooks Range.  Sheathed cottonsedge phenological development near Fairbanks, Alaska, was reported as follows [41]: new leaves initiated:  June to early July flowers:  June to mid-July fruits:  July seeds dispersed:  late July to mid-August senescence:  late July to August Sheathed cottonsedge in the Adirondack Mountains fruits from June 9 to July 6, and seed is disseminated before late September [33].


SPECIES: Eriophorum vaginatum
FIRE ECOLOGY OR ADAPTATIONS : Fire-free intervals in sheathed cottonsedge tussock tundra are not well documented.  Fire on the Seward Peninsula appears to be frequent (11.9 lightning fires per 2,000 sq mi [5,000 sq km] per 23 yr).  Farther northeast in the Noatak River Valley, fire frequency appears to be 7.3 fires per 2,000 square miles per 23 years [45]. Fire is important in maintaining the long-term growth and survival of sheathed cottonsedge.  In the absence of fire, sheathed cottonsedge tussock-shrub tundra undergoes a series of autogenic successional changes.  These changes involve the accumulation of peat and burial or submergence of tussocks by dwarf shrubs, mosses, and lichens.  This results in raised permafrost levels, reduced frost action, and senescence of tussocks.  Frost action prevents such changes by churning soils, incorporating organics, and preventing the buildup of dwarf shrubs, mosses, and lichens.  Frost action is renewed when enough organics are burned so that thaw depth reaches into mineral soils [26,44,59]. Sheathed cottonsedge survives fire because its growing points are insulated by tightly bunched dead and live tillers, stem sheaths, and scales.  The elevated position of tussocks increases resistance to ground fire [62].  Fire provides an opportunity for seedling establishment.  Since sheathed cottonsedge has both shallowly and deeply buried seed, some viable seed is available regardless of depth of burn into the peat horizon [45,62].  Burned peat is an ideal seedbed.  In a comparison of sheathed cottonsedge seedling emergence on different substrates, burned peat showed highest rates of emergence.  The study also showed that sheathed cottonsedge seedling emergence is greater where fire has melted soil ice and deepened the active soil layer. Additionally, the study showed that fire releases nutrients and enriches tundra soils [62]. POSTFIRE REGENERATION STRATEGY :    Tussock graminoid    Ground residual colonizer (on-site, initial community)    Secondary colonizer - on-site seed


SPECIES: Eriophorum vaginatum
IMMEDIATE FIRE EFFECT ON PLANT : Light- to moderate-severity fire generally top-kills sheathed cottonsedge [29,61].  A survey of burns in the MacKenzie Delta of Alaska showed that tundra and tundra-forest wildfires burned aboveground portions of sheathed cottonsedge tussocks.  Protective sheaths and scales were charred but meristematic tissue was unharmed [3].  Severe fire may kill tussocks [45]. Vogl [59] reported that some sheathed cottonsedge tussocks were killed during prescribed burning in north-central Wisconsin. DISCUSSION AND QUALIFICATION OF FIRE EFFECT : NO-ENTRY PLANT RESPONSE TO FIRE : Sheathed cottonsedge sprouts from burned tillers and establishes from seed following fire [3].  Flower and tiller production increase after top-kill [2,37,45].  Near Mile 107, Elliot Highway, Alaska, tussock tillers sprouted from the rootstock during the first postfire growing season following a severe prescription fire.  Seedling density was 180 per square yard (198/sq m) at postfire year 1.  Sprouting tillers flowered at postfire year 2.  Flowering was significantly (p>0.01) greater in burned than in unburned tussocks [62].  Another study found that plants in northwestern Alaska maintained increased flower production for 9 years after wildfire [45]. Two years following prescribed burning in north-central Wisconsin, average frequency of sheathed cottonsedge was 27.5 percent in burned areas and 35.0 percent in adjacent unburned areas [59].  Aboveground average biomass of sheathed cottonsedge was 15 grams per square meter one year after wildfire near Fairbanks (average biomass of unburned areas was 17.8 g/sq m).  Biomass was 107 grams per square meter at postfire year 13 (average biomass of unburned areas was 5.5 g/sq m) [13]. DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : Response to wildfireThe Imurak Lake area is located in the central part of the Seward Peninsula of Alaska (65 deg 35 min N., 163 deg 20 min W.).  It is within the Bering Land Bridge National Monument and is administered by the National Park Service.  At the time of the fire, it was administered by the Bureau of Land Management.  Study sites were on the southwest slope of Nimrod Hill (Bendelben C-3 quadrangle on USGS topographical map) [44,45,66]. Sheathed cottonsedge tussocks dominated the footslope of Nimrod Hill. Sheathed cottonsedge frequency was 10 percent; density was 34 shoots per square meter.  Areas between tussocks were occupied by dwarf shrubs, mosses, and lichens.  Dwarf shrubs present were bog Labrador tea (Ledum palustre), cloudberry (Rubus chamaeorus), mountain cranberry (Vaccinium vitis-idaea), bog blueberry (V. uliginosum), crowberry (Empetrum nigrum), and dwarf arctic birch (Betula nana).  Mosses were Sphagnum spp., Dicranum elongatum, Hypnum pratense, and Aulocimium palustre. Also present were reindeer lichens (Cladonia gracilis, C. rangiferina), caribou lichens (Cetraria cuclata), and dogtooth lichen (Peltigera aphthosa).  Imurak Lake was downslope from this sheathed cottonsedge-ericaceous shrub community.  A dwarf arctic birch-ericaceous shrub community was upslope [44,45,66]. Imurak Lake Fire study sits were located along a topographic transect from the bottom to the top of Nimrod Hill.  Slope was gentle (1-9%) on the footslope where the sheathed cottonsedge-ericaceous shrub community occurred.  Footslope elevation was 1,100 to 1,350 feet (335-411 m). Soil was moist.  Texture of the soil mineral fraction was silty clay-loam.  Frost depth was 11.6 inches (29 cm).  The organic layer was 3.6 to 17.2 inches (19-43 cm) thick [44,45]. The Imurak Lake Fire was ignited by lightning.  Fire was moderate to severe in the dwarf arctic birch-ericaceous shrub community.  It moved downslope from that community into sheathed cottonsedge-ericaceous shrub, where it lowered to light and moderate severity [44,45]. Sheathed cottonsedge-ericaceous shrub tundra had the fastest postfire regeneration rates of all plant communities burned, with 15 to 20 percent cover at postfire year 1.  Sheathed cottonsedge cover averaged 17.4 percent; average density of mature plants was 3.5 shoots per square meter.  Tussocks on old frost scars apparently sprouted more vigorously than tussocks on other substrates and produced more flowers at postfire year 2.  Distinction between sheathed cottonsedge seedlings and Carex spp. seedlings was difficult at postfire year 1 because they were less than 0.4 inch (1 cm) tall.  Total sedge seedling density, however, was greater than 100 per square meter.  After 7 postfire years, evidence of fire was difficult to detect, except for the change in species composition.  Sheathed cottonsedge increased in importance as a result of fire [44]. Postfire peat thickness was 9.6 to 12 inches (24-30 cm), a reduction of 2 to 6 inches (5-15 cm) from prefire thickness.  Depth of thaw increased 12 to 14 inches (30-35 cm).  Postfire frost action created new frost scars and renewed old ones [44]. The Imurak Lake Fire demonstrates how fire benefits sheathed cottonsedge.  The fire renewed growth of senescent tussocks.  Increased depth of active soil layer and availability of fresh frost scars created opportunity for seedling establishment.  Increased soil nutrients allowed for vigorous growth of seedlings and sprouting tillers [44]. Heavy equipment was driven across the Imurak Lake Burn the spring following the fire.  It left deep tracks and ruts (up to 10 inches [25 cm] deep) and exposed mineral soil.  Racine [44] recommended that because burned tundra is particularly susceptible to disturbance, off-road vehicle traffic be prohibited except in winter when soils are frozen [44,45,66]. FIRE MANAGEMENT CONSIDERATIONS : A standing crop biomass of 400 grams per square meter or more was reported for a sheathed cottonsedge-dwarf shrub heath in interior Alaska [2]. The wind adjustment factor for predicting fire behavior in sheathed cottonsedge tussock tundra in interior Alaska is 0.75.  This is substantially higher than wind adjustment factors of other vegetation types.  If a fire moves from black spruce forest onto tussock tundra, a very rapid increase in rate of spread should be anticipated [42]. The relative fuel potentials of 12 tundra-forest ground species of the MacKenzie Delta were evaluated from measured fuel characteristics by simulating a test fire with the Rothermal fire behavior model. Sheathed cottonsedge received the lowest flammability rating of all species tested.  Other data regarding fuel characteristics of sheathed cottonsedge were listed [52]. Some Scotch heather-sheathed cottonsedge bogs in northern England are burned every 10 years in order to maximize the amount of sheathed cottonsedge available as sheep forage [22,23]. The nutritional value of sheathed cottonsedge foliage increases for the first 1 to 2 years after fire [29].

References for species: Eriophorum vaginatum

1. Ahti, T. 1959. Studies on the caribou lichen stands of Newfoundland. Annals of the Botanical Society. Vanamo. 30(4): 1-44. [18901]
2. Bliss, L. C. 1988. Arctic tundra and polar desert biome. In: Barbour, Michael G.; Billings, William Dwight, eds. North American terrestrial vegetation. Cambridge; New York: Cambridge University Press: 1-32. [13877]
3. Bliss, L. C.; Wein, R. W. 1972. Plant community responses to disturbances in the western Canadian Arctic. Canadian Journal of Botany. 50: 1097-1109. [14877]
4. Calmes, Mary A. 1976. Vegetation pattern of bottomland bogs in the Fairbanks area, Alaska. Fairbanks, AK: University of Alaska. 104 p. Thesis. [14785]
5. Chapin, F. S., III; McGraw, J. B.; Shaver, G. R. 1989. Competition causes regular spacing of alder in Alaskan shrub tundra. Oecologia. 79: 412-416. [8736]
6. Chapin, F. Stuart, III; Slack, Mari. 1979. Effect of defoliation upon root growth, phosphate absorption and respiration in nutrient-limited tundra graminoids. Oecologia. 42: 67-79. [21029]
7. Chapin, F. S., III; Shaver, G. R.; Kedrowski, R. A. 1986. Environmental controls over carbon, nitrogen and phosphorus fractions in Eriophorum vaginatum in Alaskan tussock tundra. Journal of Ecology. 4: 167-195. [21028]
8. Chester, Ann L.; Shaver, G. R. 1982. Reproductive effort in cotton grass tussock tundra. Holarctic Ecology. 5: 200-206. [21043]
9. Dyrness, C. T.; Grigal, D. F. 1979. Vegetation-soil relationships along a spruce forest transect in interior Alaska. Canadian Journal of Botany. 57: 2644-2656. [12488]
10. Ebersole, James J. 1987. Short-term vegetation recovery at an Alaskan arctic coastal plain site. Arctic and Alpine Research. 19(4): 442-450. [9476]
11. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905]
12. Famous, Norman C.; Spencer, M. 1989. Revegetation patterns in mined peatlands in central and eastern North America studied. Restoration and Management Notes. 7(2): 95-96. [10171]
13. Fetcher, Ned; Beatty, Thomas F.; Mullinax, Ben; Winkler, Daniel S. 1984. Changes in arctic tussock tundra thirteen years after fire. Ecology. 65(4): 1332-1333. [7234]
14. Fetcher, Ned; Shaver, Gaius R. 1982. Growth and tillering patterns within tussocks of Eriophorum vaginatum. Holarctic Ecology. 5: 180-186. [21042]
15. Fetcher, Ned; Shaver, G. R. 1983. Life histories of tillers of Eriophorum vaginatum in relation to tundra disturbance. Journal of Ecology. 71: 131-147. [17741]
16. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others]. 1977. Vegetation and environmental features of forest and range ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of Agriculture, Forest Service. 68 p. [998]
17. Gartner, Barbara L.; Chapin, F. Stuart, III; Shaver, Gaius R. 1983. Demographic patterns of seedling establishment and growth of native graminoids in an Alaskan tundra disturbance. Journal of Applied Ecology. 20: 965-980. [18037]
18. Gartner, B. L.; Chapin, F. S., III; Shaver, G. R. 1986. Reproduction of Eriophorum vaginatum by seed in Alaskan tussock tundra. Journal of Ecology. 74: 1-18. [21027]
19. Gleason, Henry A.; Cronquist, Arthur. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. 2nd ed. New York: New York Botanical Garden. 910 p. [20329]
20. Grant, S. A.; Torvell, L.; Smith, H. K.; [and others]. 1987. Comparative studies of diet selection by sheep and cattle: blanket bog and heather moor. Journal of Ecology. 75: 947-960. [21037]
21. Hanson, Herbert C. 1953. Vegetation types in northwestern Alaska and comparisons with communities in other arctic regions. Ecology. 34(1): 111-140. [9781]
22. Hobbs, R. J. 1984. Length of burning rotation and community composition in high-level Calluna-Eriophorum bog in northern England. Vegetatio. 57: 129-136. [19864]
23. Hobbs, R. J.; Gimingham, C. H. 1980. Some effects of fire and grazing on heath vegetation. Bulletin D' Ecologie. 11(3): 709-715. [19855]
24. Hopkins, D. M.; Sigafoos, R. S. 1950. Frost action and vegetation patterns on Seward Peninsula, Alaska. U.S. Geological Survey Bulletin. 974-C: 51-101. [20983]
25. Hulten, Eric. 1968. Flora of Alaska and neighboring territories. Stanford, CA: Stanford University Press. 1008 p. [13403]
26. Keatinge, T. H. 1975. Plant community dynamics in wet heathland. Journal of Ecology. 63: 163-172. [21122]
27. Kelso, Sylvia. 1989. Vascular flora and phytogeography of Cape Prince of Wales, Seward Peninsula, Alaska. Canadian Journal of Botany. 67: 3248-3259. [9906]
28. Klein, David. 1979. Wildfire, lichens and caribou. In: Hoefs, M.; Russell, D., eds. Wildlife and wildfire: Proceedings of workshop; 1979 November 27-28; Whitehorse, YT. Whitehorse, YT: Yukon Wildlife Branch: 37-65. [14074]
29. Klein, David R. 1982. Fire, lichens, and caribou. Journal of Range Management. 35(3): 390-395. [10898]
30. Koch, George W.; Bloom, Arnold J.; Chapin, F. Stuart, III. 1991. Ammonium and nitrate as nitrogen sources in two Eriophorum species. Oecologia. 88: 570-573. [21030]
31. Kroehler, C. J.; Linkins, A. E. 1991. The absorption of inorganic phosphate from P-labeled inositol hexaphosphate by Eriophorum vaginatum. Oecologia. 85: 424-428. [21026]
32. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation of the conterminous United States. Special Publication No. 36. New York: American Geographical Society. 77 p. [1384]
33. Kudish, Michael. 1992. Adirondack upland flora: an ecological perspective. Saranac, NY: The Chauncy Press. 320 p. [19377]
34. Kummerow, Jochen; Mills, James N.; Ellis, Barbara A.; Kummerow, Andre. 1988. Growth dynamics of cotton-grass (Eriophorum vaginatum). Canadian Journal of Botany. 66: 253-256. [21033]
35. Mark, A. F.; Chapin, F. S., III. 1989. Seasonal control over allocation to reproduction in a tussock-forming and a rhizomatous species of Eriophorum in central Alaska. Oecologia. 78: 27-34. [21031]
36. Mark, A. F.; Fetcher, Ned; Shaver, G. R.; Chapin, F. S., III. 1985. Estimated ages of mature tussocks of Eriophorum vaginatum along a latitudinal gradient in central Alaska, U.S.A. Arctic and Alpine Research. 17(1): 1-5. [21025]
37. McGraw, J. B.; Shaver, G. R. 1982. Seedling density and seedling survival in Alaskan cotton grass tussock tundra. Holarctic Ecology. 5: 212-217. [21041]
38. McGraw, J. B.; Vavrek, M. C.; Bennington, C. C. 1991. Ecological genetic variation in seed banks. I. Establishment of a time transect. Journal of Ecology. 79(3): 617-625. [20205]
39. Moorhead, Daryl L.; Kroehler, Carolyn J.; Linkins, A. E.; Reynolds, James F. 1993. Extracellular acid phosphatase activities in Eriophorum vaginatum tussocks: a modeling synthesis. Arctic and Alpine Research. 25(1): 50-55. [21194]
40. Moss, E. H. 1959. Flora of Alberta. Toronto: University of Toronto Press. 546 p. [8948]
41. Murray, Carole; Miller, Philip C. 1982. Phenological observations of major plant growth forms and species in montane and Eriophorum vaginatum tussock tundra in central Alaska. Holarctic Ecology. 5: 109-116. [21044]
42. Norum, Rodney A. 1983. Wind adjustment factors for predicting fire behavior in three fuel types in Alaska. Res. Pap. PNW-309. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 5 p. [14618]
43. Pulliainen, Erkki; Tunkkari, Paavo S. 1991. Responses by the capercaillie Tetrao urogallus, and the willow grouse Lagopus lagopus, to the green matter available in early spring. Holarctic Ecology. 14: 156-160. [21038]
44. Racine, Charles H. 1979. The 1977 tundra fires in the Seward Peninsula, Alaska: effects and initial revegetation. BLM-Alaska Technical Report 4. U.S. Department of the Interior, Bureau of Land Management, Alaska State Office. 51 p. [8330]
45. Racine, Charles H.; Johnson, Lawrence A.; Viereck, Leslie A. 1987. Patterns of vegetation recovery after tundra fires in northwestern Alaska, U.S.A. Arctic and Alpine Research. 19(4): 461-469. [6114]
46. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. [2843]
47. Roland, A. E.; Smith, E. C. 1969. The flora of Nova Scotia. Halifax, NS: Nova Scotia Museum. 746 p. [13158]
48. Scotter, George W. 1972. Chemical composition of forage plants from the Reindeer Preserve, Northwest Territories. Arctic. 25(1): 21-27. [16563]
49. Seymour, Frank Conkling. 1982. The flora of New England. 2d ed. Phytologia Memoirs 5. Plainfield, NJ: Harold N. Moldenke and Alma L. Moldenke. 611 p. [7604]
50. Stanek, W.; Alexander, K.; Simmons, C. S. 1981. Reconnaissance of vegetation and soils along the Dempster Highway, Yukon Territory: I. Vegetation types. BC-X-217. Victoria, BC: Environment Canada, Canadian Forestry Service, Pacific Forest Research Centre. 32 p. [16526]
51. Stickney, Peter F. 1989. Seral origin of species originating in northern Rocky Mountain forests. Unpublished draft on file at: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Laboratory, Missoula, MT; RWU 4403 files. 10 p. [20090]
52. Sylvester, T. W.; Wein, Ross W. 1981. Fuel characteristics of arctic plant species and simulated plant community flammability by Rothermel's model. Canadian Journal of Botany. 59: 898-907. [17685]
53. Tallis, J. H. 1964. Studies on southern Pennine peats. I. The general pollen record. Journal of Ecology. 52: 323-331. [21133]
54. Tieszen, Larry L.; Archer, Steve. 1979. Physiological responses of plants in tundra grazing systems. In: Johnson, D. A., ed. Special management needs of alpine ecosystems. Range Science Series No. 5. Denver, CO: The Society for Range Management: 22-42. [21124]
55. U.S. Department of Agriculture, Soil Conservation Service. 1982. National list of scientific plant names. Vol. 1. List of plant names. SCS-TP-159. Washington, DC. 416 p. [11573]
56. Salonen, Veikko; Penttinen, Antti; Sarkka, Aila. 1992. Plant colonization of a bare peat surface: population changes and spatial patterns. [Journal name unknown]. ?: 113-118. [21040]
57. Viereck, L. A.; Dyrness, C. T.; Batten, A. R.; Wenzlick, K. J. 1992. The Alaska vegetation classification. Gen. Tech. Rep. PNW-GTR-286. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 278 p. [2431]
58. Viereck, L. A.; Dyrness, C. T.; Batten, A. R.; Wenzlick, K. J. 1992. The Alaska vegetation classification. Gen. Tech. Rep. PNW-GTR-286. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 278 p. [2431]
59. Vogl, Richard J. 1964. The effects of fire on a muskeg in northern Wisconsin. Journal of Wildlife Management. 28(2): 317-329. [12170]
60. Vogl, Richard J. 1967. Controlled burning for wildlife in Wisconsin. In: Proceedings, 6th annual Tall Timbers Fire Ecology Conference; 1967 March 6-7; Tallahassee, FL. No. 6. Tallahassee, FL: Tall Timbers Research Station: 47-96. [18726]
61. Wein, R. W. 1974. Recovery of vegetation in arctic regions after burning. Rep. 74-6. Ottawa, ON: Canadian Task Force on Northern Oil Development. 41 p. [13001]
62. Wein, Ross W.; Bliss, L. C. 1973. Changes in Arctic Eriophorum tussock communities following fire. Ecology. 54(4): 845-852. [9827]
63. Wein, Ross W.; Bliss, L. C. 1974. Primary production in arctic cottongrass tussock tundra communities. Arctic and Alpine Research. 6(3): 261-274. [21035]
64. Wein, Ross W.; MacLean, D. A. 1973. Cotton grass (Eriophorum vaginatum) germination requirements and colonizing potential in the Arctic. Canadian Journal of Botany. 51: 2509-2513. [21036]
65. Archer, S.; Tieszen, L. L. 1983. Effects of simulated grazing on foliage and root production and biomass allocation in an arctic tundra sedge (Eriophorum vaginatum). Oecologia. 58(1): 92-102. [21125]
66. Racine, Charles H. 1981. Tundra fire effects on soils and three plant communities along a hill-slope gradient in the Seward Peninsula, Alaska. Arctic. 34(1): 71-84. [7233]