Index of Species Information
SPECIES: Danthonia compressa
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| Flattened oatgrass. Image hosted by USDA-NRCS PLANTS Database, used with permission of Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner's Sons, New York. Vol. 1: 221. |
Introductory
SPECIES: Danthonia compressa
AUTHORSHIP AND CITATION:
Carey, Jennifer H. 1994. Danthonia compressa. In: Fire Effects Information System, [Online].
U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station,
Fire Sciences Laboratory (Producer). Available:
https://www.fs.usda.gov/database/feis/plants/graminoid/dancom/all.html [].
Revisions:
On 2 October 2018, the common name of this species was changed in FEIS
from: mountain oatgrass
to: flattened oatgrass. Images were also added.
ABBREVIATION:
DANCOM
SYNONYMS:
NO-ENTRY
NRCS PLANT CODE:
DACO
COMMON NAMES:
flattened oatgrass
mountain oatgrass
slender oatgrass
TAXONOMY:
The scientific name of flattened oatgrass is Danthonia
compressa Austin [10,12,20]. It is in the family Poaceae. There are no
currently accepted infrataxa. Flattened oatgrass may intergrade with
poverty grass (Danthonia spicata), a closely related species [4,12].
LIFE FORM:
Graminoid
FEDERAL LEGAL STATUS:
No special status
OTHER STATUS:
NO-ENTRY
DISTRIBUTION AND OCCURRENCE
SPECIES: Danthonia compressa
GENERAL DISTRIBUTION:
Flattened oatgrass occurs in the eastern United States and southeastern
Canada. It occurs from extreme southeastern Ontario east through
southern Quebec to Nova Scotia and south through New England and the
Appalachian Mountain region to northern Georgia. In the southeastern
United States, flattened oatgrass is restricted to the Appalachian
Mountains [10,12,20].
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| Western (left) and eastern (right) distributions of flattened oatgrass. Maps courtesy of USDA, NRCS. 2018. The PLANTS Database.
National Plant Data Team, Greensboro, NC. [2018, October 2] [24]. |
ECOSYSTEMS:
FRES15 Oak - hickory
STATES:
CT DE GA KY ME MD MA NH NJ NY
NC OH PA RI SC TN VT VA WV NB
NS ON PQ
BLM PHYSIOGRAPHIC REGIONS:
NO-ENTRY
KUCHLER PLANT ASSOCIATIONS:
K100 Oak - hickory forest
K104 Appalachian oak forest
SAF COVER TYPES:
NO-ENTRY
SRM (RANGELAND) COVER TYPES:
NO-ENTRY
HABITAT TYPES AND PLANT COMMUNITIES:
Flattened oatgrass occurs in forest openings, open woods, and mountain
meadows.
Flattened oatgrass is dominant in grassy balds of the southern
Appalachian Mountains. Other herbaceous plants occurring in grassy
balds include redtop (Agrostis alba), timothy (Phleum pratense), Canada
bluegrass (Poa compressa), Kentucky bluegrass (P. pratense), red fescue
(Festuca rubra), five-fingers (Potentilla canadensis), and sheep sorrel
(Rumex acetosella) [4,18,26,27]
On the Allegheny Plateau in Pennsylvania, deciduous forests which failed
to regenerate after logging support a dense groundcover of flattened
oatgrass, rough goldenrod (Solidago rugosa), tall flat-topped white
aster (Aster umbellatus), and bracken fern (Pteridium aquilinum) [13].
Flattened oatgrass is listed as a dominant species in the following
publication:
Vegetation of the Great Smoky Mountains [27]
MANAGEMENT CONSIDERATIONS
SPECIES: Danthonia compressa
IMPORTANCE TO LIVESTOCK AND WILDLIFE:
Flattened oatgrass is not considered a regionally important forage
species [11,17], although it is an important pasture grass in the
Appalachian highlands [4,6].
PALATABILITY:
NO-ENTRY
NUTRITIONAL VALUE:
NO-ENTRY
COVER VALUE:
NO-ENTRY
VALUE FOR REHABILITATION OF DISTURBED SITES:
NO-ENTRY
OTHER USES AND VALUES:
NO-ENTRY
OTHER MANAGEMENT CONSIDERATIONS:
The dense growth habit and competitive nature of flattened oatgrass
restricts tree seedling establishment [26]. Where tree establishment is
desired, herbicides easily control existing flattened oatgrass.
Glyphosate does not impede germination of residual dormant seeds, but
Bromacil delays germination for more than 1 year [13].
Flattened oatgrass is host to the systemic parasitic fungus Atkinsonella
hypoxylon [6].
BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Danthonia compressa
GENERAL BOTANICAL CHARACTERISTICS:
Flattened oatgrass is a native, perennial bunchgrass. The culms are
slender, compressed, sometimes decumbent, and 12 to 32 inches (30-80 cm)
tall. The leaves are mostly at or near the base and up to 8 to 10
inches (20-25 cm) long. The inflorescence is a panicle; slender
branches bear two or three spikelets. The awn is bent and 0.2 to 0.3
inches (0.6-0.8 cm) long [4,10,12,20].
RAUNKIAER LIFE FORM:
hemicryptophyte
REGENERATION PROCESSES:
Flattened oatgrass reproduces by seed. Large amounts of seed are
produced annually, some of which remain dormant in the litter for at
least several years [13]. Flattened oatgrass also sprouts from
perennating buds at the base of the culms.
In two populations in North Carolina, flattened oatgrass produced an
average of 50 percent cleistogamous flowers [6].
SITE CHARACTERISTICS:
In the southern Appalachians, flattened oatgrass is a frequent species on
grassy balds which occupy well-drained sites on ridges, broad slopes,
and dome-shaped summits between 5,000 and 6,000 feet (1,500-1,800 m) in
elevation. Grassy balds occur on slopes of all aspects but are most
commonly found on south, southwest, and west aspects. Flattened oatgrass
grows on dry sites but is susceptible to drought [19,26]. On wetter
areas of grassy balds, flattened oatgrass dominance gives way to sedges
(Carex spp.) [26].
SUCCESSIONAL STATUS:
Flattened oatgrass grows in full sun and in open woods. It does not
persist under closed canopies [4]. It establishes on disturbed sites
including recently logged and burned areas [14,18].
Grassy balds are persistent successional communities. The origin of
grassy balds is not fully understood, but former forests may have died
from ice storms, blow downs, fire, or climate change. Woody species
establishment is often delayed on these sites by dense herbaceous
cover, harsh environment, fire, and/or grazing [3,19].
Grassy balds in the Appalachian Mountains are succeeded by Rhododendron
spp. thickets, American green alder (Alnus viridis ssp. crispa)
thickets, or spruce (Picea spp.)-fir (Abies spp.) forests. A dense
carpet of moss (Polytrichum commune) advances into the grassy bald at
the edge of the spruce-fir forest and suppresses flattened oatgrass [5].
SEASONAL DEVELOPMENT:
Flattened oatgrass generally flowers from June to August [20]. In North
Carolina, flattened oatgrass flowers from mid-June to early July [4].
FIRE ECOLOGY
SPECIES: Danthonia compressa
FIRE ECOLOGY OR ADAPTATIONS:
Flattened oatgrass occurs in oak (Quercus spp.) woods and grassy mountain
meadows which occasionally experience either lightning or human-caused
fire. Lightning commonly strikes the peaks and ridges of the southern
Appalachian Mountains from April through August [1]. Grassy balds in
the Pisgah National Forest of North Carolina respond favorably to fire,
becoming thick and lush. The low-severity fires burn very little of the
surface detritus [18]. Flattened oatgrass basal buds and dormant seeds
probably survive low-severity fire.
FIRE REGIMES:
Find 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".
POSTFIRE REGENERATION STRATEGY:
Tussock graminoid
Ground residual colonizer (on-site, initial community)
Secondary colonizer - off-site seed
FIRE EFFECTS
SPECIES: Danthonia compressa
IMMEDIATE FIRE EFFECT ON PLANT:
Fire probably kills the culms and leaves of flattened oatgrass.
PLANT RESPONSE TO FIRE:
Dormant seeds in the soil or litter germinate after fire. Flattened
oatgrass seedlings began growing 1 week after a spring fire on Gregory
Bald in the Great Smoky Mountains National Park [18]. Poverty grass, a
close relative of flattened oatgrass, regenerated from a seedbank after
fire on an upland site in Michigan [22].
FIRE MANAGEMENT CONSIDERATIONS:
Prescribed fire is used to maintain grassy balds in the southern
Appalachian Mountains. Woody species are invading many grassy balds
because of fire suppression and decreased grazing [18]. Prescribed
burning was as effective as mowing in preventing woody species
establishment in Big Meadows, Shenandoah National Park, Virginia.
Biomass in the area prescribed burned in April was equal to the unburned
control by the end of the summer [7].
Grassy balds respond well to fall fires. The fuel is less compact and
favorable weather conditions last longer in the fall than in the spring
[18].
REFERENCES
SPECIES: Danthonia compressa
REFERENCES:
1. Barden, Lawrence S.; Woods, Frank W. 1974. Characteristics of lightning
fires in southern Appalachian forests. In: Proceedings, annual Tall
Timbers fire ecology conference; 1973 March 22-23; Tallahassee, FL. No.
13. Tallahassee, FL: Tall Timbers Research Station: 345-361. [19012]
2. 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]
3. Thompson, Frank R.; Lewid, Stephen J.; Green, Janet; Ewert, David. 1993.
Status of neotropical migrant landbirds in the Midwest: identifying
species of management concern. In: Finch, Deborah M.; Stangel, Peter W.,
eds. Status and management of neotropical migratory birds: Proceedings;
1992 September 21-25; Estes Park, CO. Gen. Tech. Rep. RM-229. Fort
Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky
Mountain Forest and Range Experiment Station: 145-158. [21273]
4. Blomquist, H. L. 1948. The grasses of North Carolina. Durham, NC: Duke
University Press. 276 p. [23351]
5. Brown, Dalton Milford. 1941. Vegetation of Roan Mountain: a
phytosociological and successional study. Ecological Monographs. 11:
61-97. [23349]
6. Clay, Keith. 1983. Variation in the degree of cleistogamy within and
among species of the grass Danthonia. American Journal of Botany. 70(6):
835-843. [234]
7. Cocking, W. D.; Baxter, E. E.; Lilly, S. L. 1979. Plant community
responses to the use of prescribed burning as an alternative to mowing
in the management of Big Meadows, Shenandoah NP. In: Linn, Robert M.,
ed. Proceedings, 1st conference on scientific research in the National
Parks: Volume II; 1976 November 9-12; New Orleans, LA. NPS Transactions
and Proceedings Series No. 5. Washington, DC: U.S. Department of the
Interior, National Park Service: 1205-1207. [10545]
8. Eyre, F. H., ed. 1980. Forest cover types of the United States and
Canada. Washington, DC: Society of American Foresters. 148 p. [905]
9. 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]
10. 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]
11. Gould, Frank W.; Shaw, Robert B. 1983. Grass systematics. 2d ed. College
Station, TX: Texas A&M University Press. 397 p. [5667]
12. Hitchcock, A. S. 1951. Manual of the grasses of the United States. Misc.
Publ. No. 200. Washington, DC: U.S. Department of Agriculture,
Agricultural Research Administration. 1051 p. [2nd edition revised by
Agnes Chase in two volumes. New York: Dover Publications, Inc.]. [1165]
13. Horsley, S. B. 1981. Control of herbaceous weeds in Allegheny hardwood
forests with herbicides. Weed Science. 29: 655-662. [23352]
14. Horsley, S. B. 1982. Development of reproduction in Allegheny hardwood
stands after herbicide clearcuts and herbicide-shelterwood cuts. Res.
Note NE-308. Radnor, PA: U.S. Department of Agriculture, Forest Service,
Northeastern Forest Experimental Station. 4 p. [23353]
15. Kartesz, John T.; Kartesz, Rosemarie. 1980. A synonymized checklist of
the vascular flora of the United States, Canada, and Greenland. Volume
II: The biota of North America. Chapel Hill, NC: The University of North
Carolina Press; in confederation with Anne H. Lindsey and C. Richie
Bell, North Carolina Botanical Garden. 500 p. [6954]
16. 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]
17. Leithead, Horace L.; Yarlett, Lewis L.; Shiflet, Thomas N. 1971. 100
native forage grasses in 11 southern states. Agric. Handb. 389.
Washington, DC: U.S. Department of Agriculture, Forest Service. 216 p.
[17551]
18. Lindsay, Mary M.; Bratton, Susan Power. 1979. Grassy balds of the Great
Smoky Mountains: their history and flora in relation to potential
management. Environmental Management. 3(5): 417-430. [23347]
19. Mark, A. F. 1958. The ecology of the southern Appalachian grass balds.
Ecological Monographs. 28(4): 293-336. [23350]
20. Radford, Albert E.; Ahles, Harry E.; Bell, C. Ritchie. 1968. Manual of
the vascular flora of the Carolinas. Chapel Hill, NC: The University of
North Carolina Press. 1183 p. [7606]
21. Raunkiaer, C. 1934. The life forms of plants and statistical plant
geography. Oxford: Clarendon Press. 632 p. [2843]
22. Scheiner, Samuel M. 1988. The seed bank and above-ground vegetation in
an upland pine-hardwood succession. Michigan Botanist. 27(4): 99-106.
[12396]
23. 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]
24. U.S. Department of Agriculture, Natural Resources Conservation Service. 2018.
PLANTS Database, [Online]. U.S. Department of Agriculture, Natural Resources
Conservation Service (Producer). Available: https://plants.usda.gov/. [34262]
25. U.S. Department of the Interior, National Biological Survey. [n.d.]. NP
Flora [Data base]. Davis, CA: U.S. Department of the Interior, National
Biological Survey. [23119]
26. Wells, B. W. 1937. Southern Appalachian grass balds. Journal of the
Elisha Mitchell Scientific Society. 53(1): 1-26. [23348]
27. Whittaker, R. H. 1956. Vegetation of the Great Smoky Mountains.
Ecological Monographs. 26(1): 1-79. [11108]
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