Index of Species Information

SPECIES:  Agrostis exarata


SPECIES: Agrostis exarata
AUTHORSHIP AND CITATION : Esser, Lora L. 1994. Agrostis exarata. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: [].

ABBREVIATION : AGREXA SYNONYMS : SCS PLANT CODE : AGEX COMMON NAMES : spike bentgrass spike redtop spike bent western bentgrass TAXONOMY : The currently accepted scientific name of spike bentgrass is Agrostis exarata Trin. [1,9,11,20,27]. It is a member of the Poaceae family. There are three recognized varieties: A. e. var. exarata A. e. var. pacifica Vasey [14,20] A. e. var. monolepis (Torrey) Hitchc. [11,20,27] Spike bentgrass apparently hybridizes with ticklegrass (A. scabra) and bentgrass (A. stolonifera) [27]. LIFE FORM : Graminoid FEDERAL LEGAL STATUS : No special status OTHER STATUS : NO-ENTRY


SPECIES: Agrostis exarata
GENERAL DISTRIBUTION : Spike bentgrass is mostly a western grass. It occurs from Manitoba, South Dakota, Nebraska, Texas, and Mexico west to the Pacific states and provinces, including Alaska [8,12,18]. Spike bentgrass is widely distributed in the mountains of northern California and occurs on Santa Cruz Island, off the coast of southern California [5]. Zifka [30] discovered an adventive colony of spike bentgrass (Agrostis exarta var. monolepis) in Rutland County, Vermont, in 1982. ECOSYSTEMS : FRES20 Douglas-fir FRES21 Ponderosa pine FRES23 Fir - spruce FRES26 Lodgepole pine FRES28 Western hardwoods FRES29 Sagebrush FRES34 Chaparral - mountain shrub FRES35 Pinyon - juniper FRES36 Mountain grasslands FRES37 Mountain meadows FRES38 Plains grasslands FRES41 Wet grasslands FRES44 Alpine STATES : AK AZ CA CO ID HI MT NE NV NM OK OR SD TX UT VT WA WY AB BC MB SK MEXICO BLM PHYSIOGRAPHIC REGIONS : 1 Northern Pacific Border 2 Cascade Mountains 3 Southern Pacific Border 4 Sierra Mountains 5 Columbia Plateau 6 Upper Basin and Range 7 Lower Basin and Range 8 Northern Rocky Mountains 9 Middle Rocky Mountains 10 Wyoming Basin 11 Southern Rocky Mountains 12 Colorado Plateau 13 Rocky Mountain Piedmont 14 Great Plains 15 Black Hills Uplift 16 Upper Missouri Basin and Broken Lands KUCHLER PLANT ASSOCIATIONS : K002 Cedar - hemlock - Douglas-fir forest K005 Mixed conifer forest K008 Lodgepole pine - subalpine forest K010 Ponderosa shrub forest K011 Western ponderosa forest K012 Douglas-fir forest K015 Western spruce - fir forest K016 Eastern ponderosa forest K017 Black Hills pine forest K018 Pine - Douglas-fir forest K020 Spruce - fir - Douglas-fir forest K022 Great Basin pine forest K023 Juniper - pinyon woodland K024 Juniper steppe woodland K026 Oregon oakwoods K030 California oakwoods K033 Chaparral K035 Coastal sagebrush K047 Fescue - oatgrass K049 Tule marshes K051 Wheatgrass - bluegrass K052 Alpine meadows and barren K055 Sagebrush steppe K056 Wheatgrass - needlegrass shrubsteppe K063 Foothills prairie K064 Grama - needlegrass - wheatgrass K065 Grama - buffalograss K066 Wheatgrass - needlegrass K068 Wheatgrass - grama - buffalograss SAF COVER TYPES : 42 Bur oak 201 White spruce 203 Balsam poplar 206 Engelmann spruce - subalpine fir 209 Bristlecone pine 210 Interior Douglas-fir 216 Blue spruce 217 Aspen 218 Lodgepole pine 219 Limber pine 222 Black cottonwood - willow 233 Oregon white oak 235 Cottonwood - willow 237 Interior ponderosa pine 238 Western juniper 239 Pinyon - juniper 250 Blue oak - Digger pine 252 Paper birch 256 California mixed subalpine SRM (RANGELAND) COVER TYPES : NO-ENTRY HABITAT TYPES AND PLANT COMMUNITIES : Spike bentgrass occurs in a wide variety of habitat types including pinyon-juniper (Pinus-Juniperus spp.), aspen (Populus spp.), fir-spruce (Abies-Picea spp.), ponderosa pine (Pinus ponderosa), lodgepole pine (P. contorta), subalpine forest, coastal sage scrub, meadow, alpine, and tundra [3,5,19,27,28]. In Utah, spike bentgrass is a common grass in wet meadows and parklands in mountain grassland communities and moist, semishaded sites in aspen communities. It is also is found in sagebrush (Artemisia spp.) communities [29]. In the Black Hills of western South Dakota, spike bentgrass is a common understory species in quaking aspen (Populus tremuloides) communities [32]. In northwestern Oregon, spike bentgrass is a component of the Douglas-fir (Pseudotsuga menziesii) forest [17]. Along montane forest river valleys in Colorado, spike bentgrass occurs in cottonwood-willow (Populus-Salix spp.) and red-osier dogwood (Cornus sericea) associations [2]. Spike bentgrass is a member of the pink mountain heather-white mountain heather (Phyllodoce empetriformis-Cassiope mertensiana) meadow community in northwestern Washington [3]. In the annual grasslands of California, spike bentgrass is a member of the fescue-oatgrass (Festuca-Danthonia) community [10]. In southern California, it is also a member of coastal sage scrub, particularly the purple sage (Salvia leucophylla) association [28]. Spike bentgrass occurs in tundra on the northeastern arctic slope of Alaska [19]. The following publication lists spike bentgrass as a community dominant: The chaparral vegetation of Santa Cruz Island, California [5] Species not previously mentioned but commonly associated with spike bentgrass in the Rocky Mountain states include American hazel (Corylus americana), thinleaf alder (Alnus incana ssp. tenuifolia), Rocky Mountain maple (Acer glabrum), common chokecherry (Prunus virginiana), Saskatoon serviceberry (Amelanchier alnifolia), shinyleaf spiraea (Spiraea lucida), silver buffaloberry (Shepherdia argentea), Kentucky bluegrass (Poa pratense), bluejoint reedgrass (Calamagrostis canadensis), beaked sedge (Carex rostrata), water sedge (C. aquatilis), field horsetail (Equisetum arvense), hairy willowweed (Epilobium ciliatum), Richardson geranium (Geranium richardsonii), smooth aster (Aster laevis), cream peavine (Lathyrus ochroleucus), wild sarsaparilla (Aralia nudicaulis), white clover (Trifolium repens), and false-Solomon's-seal (Smilacina stellata) [2,32]. Species not previously mentioned but commonly associated with spike bentgrass in California include California scrub oak (Quercus dumosa), chamise (Adenostoma fasciculatum), toyon (Heteromeles arbutifolia), hollyleaf cherry (Prunus ilicifolia), sugar sumac (Rhus ovata), tree poppy (Dendromecon rigida), coyote brush (Baccharis pilularis), Catalina bedstraw (Galium catalinense), southern bush monkeyflower (Mimulus longiflorus), tufted hairgrass (Deschampsia cespitosa), nodding trisetum (Trisetum cernuum), Geyer oniongrass (Melica geyeri), soft chess (Bromus mollis), red brome (B. rubens), wild oat (Avena fatua), foxtail barley (Critestion jubatum), naked sedge (Calamagrostis nutkaensis), and prairie junegrass (Koeleria macrantha) [5,10].

SPECIES: Agrostis exarata
IMPORTANCE TO LIVESTOCK AND WILDLIFE : Spike bentgrass is an important source of montane forage for livestock in the summer [24,27,29,32]. Herbage stays green and palatable throughout the summer [24,27,29]. PALATABILITY : Spike bentgrass is rated good for cattle, horses, and elk, and fair to good for sheep and deer [29]. NUTRITIONAL VALUE : NO-ENTRY COVER VALUE : NO-ENTRY VALUE FOR REHABILITATION OF DISTURBED SITES : Spike bentgrass has been used as a soil stabilizer in degraded areas [27]. OTHER USES AND VALUES : NO-ENTRY OTHER MANAGEMENT CONSIDERATIONS : Spike bentgrass is considered the most valuable native redtop (Agrostis spp.) on California rangelands because of its abundance and wide distribution [24]. Spike bentgrass decreases with overgrazing in climax meadows of the Sierra Nevada [21]. In the spring of 1972, there was a spill of diesel fuel in a subalpine meadow on Mount Baker, Washington. The estimated prespill cover of spike bentgrass was minute. All plants were killed by the diesel fuel. Spike bentgrass was not found in a survey of the area conducted in 1980 [3].


SPECIES: Agrostis exarata
GENERAL BOTANICAL CHARACTERISTICS : Spike bentgrass is a native, perennial bunchgrass. Culms are slender and erect, usually 3.3 to 5 feet (1-1.5 m) tall [1,11,20,24]. The blades are ascending to spreading, 0.08 to 0.4 inch (2-10 mm) wide, and up to 8 inches (20 cm) long [9,11,16]. The panicle is narrow, open to spikelike, and 4 to 10 inches (10-25 cm) tall [1,9]. Spike bentgrass occasionally develops slender rhizomes [11,16]. RAUNKIAER LIFE FORM : Hemicryptophyte REGENERATION PROCESSES : Spike bentgrass reproduces primarily by seed but may also spread laterally by rhizomes [11,24]. Seeds colonize recently disturbed sites that have exposed mineral soil seedbeds [13]. SITE CHARACTERISTICS : Spike bentgrass occurs in a wide variety of habitats including woodlands, forest openings, grasslands, shrublands, meadows, marshes, and stream and lake margins [9,18,24,29]. It is most commonly found in moist open places [1,12,20] but is also found in dry habitats such as semiarid grasslands [10,19]. Spike bentgrass grows on disturbed sites such as ditches and along roadsides [11,30]. Spike bentgrass occurs from sea level to alpine zones [5,10,18,20,29]. It occupies sites as high as 10,500 feet (3,150 m) in Utah [29]. Spike bentgrass grows well on soils derived from schists, limestones, sandstones, and conglomerates [32]. SUCCESSIONAL STATUS : Facultative Seral Species Spike bentgrass is generally a pioneer species. It is relatively shade intolerant and thrives in open, sunny locations [13]. Seed becomes established on bare mineral soil. Seedlings of spike bentgrass become established on old-growth forests that have been recently harvested [13]. Once spike bentgrass becomes established, it may remain important throughout the early seral stages [13]. Spike bentgrass is a component of relatively undisturbed riparian communities in Colorado [2]. In the Sierra Nevada, spike bentgrass may occur in climax meadow vegetation [21]. SEASONAL DEVELOPMENT : Spike bentgrass flowers from June to August [16,20]. Seed ripens and sheds during August and September, depending on altitude [24].


SPECIES: Agrostis exarata
FIRE ECOLOGY OR ADAPTATIONS : No information was available in the literature concerning spike bentgrass fire ecology or adaptations. However, a similar species, ticklegrass (Agrostis scabra), colonizes bare mineral soil on recently burned sites and may store seeds in the soil for short durations, allowing for early establishment of areas burned in the spring (see the FEIS write-up for Agrostis scabra). POSTFIRE REGENERATION STRATEGY : Tussock graminoid Initial-offsite colonizer (off-site, initial community)


SPECIES: Agrostis exarata
IMMEDIATE FIRE EFFECT ON PLANT : Grasses are generally top-killed by fire so spike bentgrass is probably top-killed by fire. Specific fire effects, however, are not described in the literature. DISCUSSION AND QUALIFICATION OF FIRE EFFECT : NO-ENTRY PLANT RESPONSE TO FIRE : No specific information on spike bentgrass response to fire is available in the literature. Ticklegrass, a similar species, increases in abundance in response to fire (see the FEIS write-up for Agrostis scabra). DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : NO-ENTRY FIRE MANAGEMENT CONSIDERATIONS : Since spike bentgrass is considered a decreaser species when overgrazed [21], fire plans may have to be coordinated with grazing management to ensure seedling establishment.


SPECIES: Agrostis exarata
REFERENCES : 1. Anderson, J. P. 1959. Flora of Alaska and adjacent parts of Canada. Ames, IA: Iowa State University Press. 543 p. [9928] 2. Baker, William L. 1989. Classification of the riparian vegetation of the montane and subalpine zones in western Colorado. Great Basin Naturalist. 49(2): 214-228. [7985] 3. Belsky, Joy. 1982. Diesel oil spill in a subalpine meadow: 9 years of recovery. Canadian Journal of Botany. 60: 906-910. [13846] 4. Bernard, Stephen R.; Brown, Kenneth F. 1977. Distribution of mammals, reptiles, and amphibians by BLM physiographic regions and A.W. Kuchler's associations for the eleven western states. Tech. Note 301. Denver, CO: U.S. Department of the Interior, Bureau of Land Management. 169 p. [434] 5. Bjorndalen, Jorn Erik. 1978. The chaparral vegetation of Santa Cruz Island, California. Norwegian Journal of Botany. 25: 255-269. [7851] 6. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905] 7. 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] 8. Great Plains Flora Association. 1986. Flora of the Great Plains. Lawrence, KS: University Press of Kansas. 1392 p. [1603] 9. Hallsten, Gregory P.; Skinner, Quentin D.; Beetle, Alan A. 1987. Grasses of Wyoming. 3rd ed. Research Journal 202. Laramie, WY: University of Wyoming, Agricultural Experiment Station. 432 p. [2906] 10. Heady, Harold F.; Foin, Theodore C.; Hektner, Mary M.; [and others]. 1977. Coastal prairie and northern coastal scrub. In: Barbour, Michael G.; Major, Jack, eds. Terrestrial vegetation of California. New York: John Wiley and Sons: 733-760. [7211] 11. Hickman, James C., ed. 1993. The Jepson manual: Higher plants of California. 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Tech. Rep. RM-238. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 681 p. [22534] 17. Lavender, Denis P. 1958. Effect of ground cover on seedling germination and survival. Research Note No. 38. Corvallis, OR: State of Oregon, Forest Lands Research Center, Dale N. Bever, Acting Director. 32 p. [401] 18. Mason, Herbert L. 1957. A flora of the marshes of California. Berkeley, CA: University of California Press. 878 p. [16905] 19. Murray, David F. 1992. Vascular plant diversity in Alaskan arctic tundra. Northwest Environmental Journal. 8: 29-52. [21459] 20. Munz, Philip A. 1973. A California flora and supplement. Berkeley, CA: University of California Press. 1905 p. [6155] 21. Ratliff, Raymond D. 1985. Meadows in the Sierra Nevada of California: state of knowledge. Gen. Tech. Rep. PSW-84. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 52 p. [8275] 22. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. [2843] 23. Reed, Porter B., Jr. 1988. National list of plant species that occur in wetlands: California (Region O). Biological Report 88(26.10). Washington, DC: U.S. Department of the Interior, Fish and Wildlife Service. In cooperation with: National and Regional Interagency Review Panels. 135 p. [9312] 24. Sampson, Arthur W.; Chase, Agnes; Hedrick, Donald W. 1951. California grasslands and range forage grasses. Bull. 724. Berkeley, CA: University of California College of Agriculture, California Agricultural Experiment Station. 125 p. [2052] 25. 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. 7 p. [20090] 26. 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] 27. Welsh, Stanley L.; Atwood, N. Duane; Goodrich, Sherel; Higgins, Larry C., eds. 1987. A Utah flora. Great Basin Naturalist Memoir No. 9. Provo, UT: Brigham Young University. 894 p. [2944] 28. Westman, W. E. 1983. Xeric Mediterranean-type shrubland associations of Alta and Baja California and the community/continuum debate. Vegetatio. 52: 3-19. [12000] 29. Vallentine, John F. 1961. Important Utah range grasses. Extension Circular 281. Logan, UT: Utah State University. 48 p. [2937] 30. Zika, Peter F. 1991. The first report of Agrostis exarata var. monolepsis (Poaceae) in New England. Rhodora. 93(876): 398-399. [24416] 31. Hitchcock, C. Leo; Cronquist, Arthur. 1973. Flora of the Pacific Northwest. Seattle, WA: University of Washington Press. 730 p. [1168] 32. Severson, Kieth E.; Thilenius, John F. 1976. Classification of quaking aspen stands in the Black Hills and Bear Lodge Mountains. Res. Pap. RM-166. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 24 p. [2111]

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