Mutton grass showed poor recovery after prescribed fall burning in one
study. Over 8 years time, three prescribed November fires were
conducted in ponderosa pine in Arizona, resulting in 2-, 5-, and
7-year-old burns. Mutton grass production was less on burned plots than
on unburned control plots regardless of time since fire. In contrast,
three other bunchgrass species recovered from the fires within 5 years:
Their production on the 5- and 7-year-old burns matched or exceeded
production on control plots. Production* of mutton grass was as follows
[1]:
2-yr-old burn 5-yr-old burn 7-yr-old burn
burned plot 0.15 (0.12) 3.49 (1.66) 1.11 (0.34)
control plot 3.56 (2.95) 7.44 (1.72)** 2.60 (0.51)**
*Production is predicted dry weight (kg/ha) based on basal diameter and
regression equations. Data are means (standard errors).
**Indicates significant difference (p=0.05) between burn and control
The degree to which mutton grass provides cover for small animals has
been rated as follows [11]:
Mutton grass is a cool-season perennial bunchgrass with occasional short
rhizomes. It is a short to mid-grass with 1- to 2-foot-long (0.3-0.6 m)
culms [29,32,53]. Basal diameter ranges from less than an inch (2.5
cm) to about 1 foot (0.3 m) [32]. Mutton grass is dioecious. Plants
are mostly pistillate, with occasional staminate or perfect flowers
[29,30,50]. Most leaves are basal [29]. The dry, papery sheath bases
of previous years do not readily disintegrate into fibers and are a
conspicuous feature of the species [60].
Mutton grass is drought resistant [7,53,60].
Mutton grass occurs from British Columbia east to Manitoba and south to
the Dakotas, western Texas, California, and northern Mexico [30,60].
Subspecies distribution: Poa fendleriana ssp. albescens occurs primarily
in the Sierra Occidental of Sonora and Chihuahua, Mexico, but its
distribution reaches north to southeastern Arizona and southwestern New
Mexico [47,50].
Poa f. ssp. fendleriana occurs from Sonora north to Utah, Colorado, and
western portions of the Dakotas [47,50].
Poa f. ssp. longiligula is the most widely distributed subspecies. It
occurs from Baja California north to British Columbia; east to Manitoba;
and south to Arizona and New Mexico [47,50].
Populations with intermediate morphology occur in transition zones
between subspecies [47].
Fires have been variously reported as harming [1,13,12], having no
effect on [57,58,61], or increasing [17] mutton grass. Mutton grass may
be harmed by severe wildfire [13,12]. Most studies suggest that it is
relatively unaffected by prescribed fall burning [24,57,58,61]. One
study, however, reported a long-term (7-year) decrease in mutton grass
after prescribed fall fire [1].
In fire-adapted forest ecosystems, fire is important in maintaining
mutton grass in the herbaceous understory. Mutton grass occurs on open,
sunny sites and in partial shade [2,43,60]; it has not been reported in
closed-canopy forests. Mutton grass is likely to decline as canopy
closure occurs with fire exclusion.
Mutton grass recovers from fire primarily by sprouting from burned
plants. Some mutton grass seedlings establish after fire, but postfire
tillering is probably more important than postfire seedling
establishment in this species [57,58,61].
Production of mutton grass and other herbaceous forage was increased by
prescribed fire in ponderosa pine near Flagstaff, Arizona. Management
objectives were to reduce fuels, thin the forest overstory, and increase
ponderosa pine seedling establishment. Prefire litter depth was 1.5 to
3 inches (7 cm). Two one-quarter acre (0.1 ha) areas were burned.
Surface fires with average flame lengths of 2 feet (0.6 m) were
attained; estimated fire intensities at the two areas were 48 BTUs per
second per foot and 90 BTUs per second per foot. Before the fire,
herbage production was primarily mullein (Verbascum thapsus), an
unpalatable forb. After fire, mutton grass, bottlebrush squirreltail
(Elymus elymoides), and palatable herbs were primary producers. Herbage
production on one of the burned areas was 3 pounds per acre (3.4 kg/ha)
before fire; 40 pounds per acre (45 kg/ha) at postfire year 1; and 40
pounds per acre (45 kg/ha) at postfire year 11. Herbage production on
the other area was 5 pounds per acre (5.6 kg/ha) before fire; 5 pounds
per acre (5.6 kg/ha) at postfire year 1; and 17 pounds per acre (19
kg/ha) at postfire year 11. The prescribed fire met management
objectives, and increased production of palatable forage was an added
bonus [17].
Mutton grass occurs mainly on dry sites such as mesas, hillsides, and
dry woods [27,29,47]. It sometimes occurs on wetter sites, however. It
has been noted in riparian zones in Zion National Park, Utah [27].
In a study of 21 burn sites in the Great Basin of California and Nevada,
Koniak [35] found that mutton grass was associated with east slopes.
Mutton grass tolerates a wide range of soil textures [16,18,26,53] and
pH. Mutton grass occurs on limestone soils in the Grand Canyon [26].
On the San Bernardino National Forest of California, mutton grass
occurred on noncarbonate substrates and also on sites that were
surfaced-mined for limestone [21].
Distributions of sexual and apomictic races of mutton grass are linked
to climate. Sexually reproducing populations occur in mild climates
that receive significant summer precipitation. Apomictic populations
tolerate colder and sometimes wetter climates but are restricted by the
Polar Front gradient in the north. They appear to be only slightly more
tolerant to hot desert climates than sexual populations. Apomictic
populations also occur at higher and lower elevations than do their
sexually reproducing counterparts. The total geographic range of Poa
fendleriana ssp. longiligula, for example, is about 20 times broader
than that of sexual P. f. ssp. longiligula [50].
Elevational ranges of mutton grass are as follows:
Arizona - 5,000 to 11,000 feet (1500-3330 m) [32]
California - 10,800 to 13,100 feet (3300-4000 m) [30]
Colorado - 5,000 to 11,500 feet (1500-3450 m) [29]
New Mexico - 4,000 to 11,000 feet (1220-3350 m) [47]
Utah - 3,000 to 12,000 feet (910-3660 m) [60]
206 Engelmann spruce-subalpine fir
210 Interior Douglas-fir
217 Aspen
220 Rocky Mountain juniper
237 Interior ponderosa pine
238 Western juniper
239 Pinyon-juniper
240 Arizona cypress
247 Jeffrey pine
256 California mixed subalpine
FRES20 Douglas-fir
FRES21 Ponderosa pine
FRES23 Fir-spruce
FRES28 Western hardwoods
FRES29 Sagebrush
FRES30 Desert shrub
FRES34 Chaparral-mountain shrub
FRES35 Pinyon-juniper
FRES36 Mountain grasslands
FRES37 Mountain meadows
FRES38 Plains grasslands
FRES40 Desert grasslands
FRES44 Alpine
K015 Western spruce-fir forest
K020 Spruce-fir-Douglas-fir forest
K021 Southwestern spruce-fir forest
K023 Juniper-pinyon woodland
K024 Juniper steppe woodland
K031 Oak-juniper woodlands
K032 Transition between K031 and K037
K037 Mountain-mahogany-oak scrub
K038 Great Basin sagebrush
K051 Wheatgrass-bluegrass
K052 Alpine meadows and barren
K055 Sagebrush steppe
K056 Wheatgrass-needlegrass shrubsteppe
K063 Foothills prairie
K065 Grama-buffalograss
K066 Wheatgrass-needlegrass
K067 Wheatgrass-bluestem-needlegrass
K068 Wheatgrass-grama-buffalograss
K069 Bluestem-grama prairie
101 Bluebunch wheatgrass
104 Antelope bitterbrush-bluebunch wheatgrass
107 Western juniper/big sagebrush/bluebunch wheatgrass
210 Bitterbrush
216 Montane meadows
301 Bluebunch wheatgrass-blue grama
314 Big sagebrush-bluebunch wheatgrass
317 Bitterbrush-bluebunch wheatgrass
322 Curlleaf mountain-mahogany-bluebunch wheatgrass
401 Basin big sagebrush
402 Mountain big sagebrush
403 Wyoming big sagebrush
409 Tall forb
410 Alpine rangeland
411 Aspen woodland
412 Juniper-pinyon woodland
413 Gambel oak
415 Curlleaf mountain-mahogany
416 True mountain-mahogany
417 Littleleaf mountain-mahogany
421 Chokecherry-serviceberry-rose
422 Riparian
503 Arizona chaparral
504 Juniper-pinyon pine woodland
509 Transition between oak-juniper woodland and mahogany-oak association
607 Wheatgrass-needlegrass
612 Sagebrush-grass
715 Grama-buffalograss
733 Juniper-oak
Mutton grass is unharmed to slightly harmed by light-severity fall fire.
Several studies have reported no significant change in mutton grass
following prescribed fall burning [24,57,58,61]. In some cases,
light-severity fall fire can benefit mutton grass by reducing
interference from other herbs [17].
Because mutton grass is a cool-season species that acquires most of its
growth in spring, prescribed spring fire may be more harmful to mutton
grass than prescribed fall fire. Literature regarding mutton grass
recovery from spring fire is lacking, however. Mutton grass appears to
be harmed by and slow to recover from severe fire [12,13].
Mutton grass provides good to excellent forage for livestock. It is
considered one of the best forage grasses in Arizona, particularly as
summer feed for domestic sheep. In Colorado, livestock graze mutton
grass from early spring to mid-summer [29].
Mutton grass also provides good forage for wildlife. Mountain goat
graze mutton grass [45]. Deer and elk make heavy use of it, especially
in early spring when other green forage is scarce [9,10,53,59].
Depending upon availability of other nutritious forage, deer may use
mutton grass in all seasons [59]. Mutton grass cures well and is an
important fall and winter deer food in some areas [32]. In northern
Colorado, mule deer consumed mutton grass from December until March.
After March, their diet was primarily forbs and green twigs of woody
plants [59].
Mutton grass is common in sagebrush (Artemisia spp.), scrub oak (Quercus
spp.), pinyon-juniper (Pinus-Juniperus spp.), mountain brush, ponderosa
pine (P. ponderosa), and fir-spruce (Abies-Picea spp.) communities. It
occurs on edges of quaking aspen (Populus tremuloides) communities,
riparian zones, and exposed alpine ridges. It is occasional in desert
shrub and mountain meadow communities and on talus [60]. In Arizona, it
extends from the spruce-fir zone down to desert grassland and Arizona
cypress (Cupressus arizonica) woodland [50].
Kuchler [36] described mutton grass as a dominant understory species in
yellow pine (Pinus ponderosa ssp. scopulorum and P. p. ssp. arizonica)
forests of southern Arizona. Other publications describing plant
communities in which mutton grass is a dominant component of the
vegetation follow.
A preliminary classification of the natural vegetation of Colorado [3]
Sagebrush-steppe habitat types in northern Colorado: a first
approximation [18]
A habitat type classification system for ponderosa pine forests of
northern Arizona [26]
Habitat types on selected parts of the Gunnison and Uncompahgre
National Forests [34]
A classification of spruce-fir and mixed conifer habitat types of
Arizona and New Mexico [38]
A preliminary classification of high-elevation sagebrush-grass
vegetation in northern and central Nevada [39]
Shrub-steppe habitat types of Middle Park, Colorado [54]
Plant associations (habitat types) of Region 2., 3rd ed. [55]
Mutton grass is able to withstand moderately heavy grazing [22,37].
Because of its high forage value and vigor, range managers generally
seek to improve or maintain mutton grass stands. On Arizona rangelands,
it is recommended that at least one-fourth of the previous year's seed
production remains by the time new mutton grass seedheads are ripe in
summer. Degraded ranges should be left to rest in July and August of
alternate years so that mutton grass can increase vigor and set good
seed crops [32].
In Utah juniper (Juniperus osteosperma) rangeland of Arizona, mutton
grass and other cool-season grasses were eliminated from the understories
of allotments where continuous cattle grazing had been practiced for
decades. The understories of continuously grazed allotments were
near-monocultures of blue grama (Bouteloua gracilis) with 65 percent
average bare ground. Mutton grass and other cool-season grasses were
present and increasing in abundance on one allotment, however. The
allotment had once been continuously grazed, but a deferred
rest-rotation system had been practiced for the past 20 years. Average
percent composition of mutton grass on ungrazed, continuously grazed,
and rest-rotation grazed sites follows. Soils were similar on all sites
except that soil structure was lacking on continuously grazed sites [4].
Ungrazed* Continuous Rest-Rotation
grazing grazing
______________________________________
45% 0% 25%
*The ungrazed site was on a mesa, inaccessible to cattle, where relict
vegetation was present.
Mule deer and cattle may select different bluegrasses (Poa spp.) when
sharing a range. In ponderosa pine in central Colorado, mule deer
preferred mutton grass, while cattle selected Kentucky bluegrass (P.
pratensis) over mutton grass [9].
Average percent composition and energy content of fresh mutton grass,
collected from various locations in the western United States, was as
follows [40]:
Protein (N x 6.25,%) 7.0 Digestible energy (kcal/kg)
Digestible protein cattle 2.58
cattle 3.8 domestic sheep 2.69
domestic sheep 3.5
horses 3.5
domestic rabbit 4.1
domestic goat 3.1
ash 11.1%
Crude fiber 33.5%
Ether extract 2.4%
N-free extract 46.0%
Nutritional content of mutton grass on the Medicine Bow National Forest
of Wyoming varied seasonally as follows [5]:
Date Ether Crude Crude
Collected Moisture Ash extract fiber protein Carotene
______________________________________________________________
(1947) (%) (%) (%) (%) (%) (?g/g)
______________________________________________________________
6/10 5.34 7.12 2.72 32.42 8.56 100
7/9 5.85 10.40 2.47 32.87 7.51 59
8/7 6.10 10.39 2.19 32.50 6.12 54
9/4 5.65 11.87 2.29 30.51 5.40 23
10/3 5.99 12.62 1.71 29.54 5.34 7
AZ CA CO ID MT NE NV NM ND OR
SD TX UT WA WY
AB BC MB SK
MEXICO
Mutton grass has a deep, fibrous root system that provides good soil
erosion control [53]. Use of mutton grass in restoration projects is
limited, however, because mutton grass seed is not commercially
available [10].
Palatability of mutton grass is excellent for cattle and horses and good
for elk, deer, pronghorn, and domestic sheep [11,29,32,53]. Mutton
grass cures well; palatability of fall foliage is rated as fair in
Arizona [32].
The palatability of mutton grass for small animals has been rated as
follows [11]:
UT WY
Small mammals good good
Small nongame birds fair good
Upland game birds fair good
Waterfowl poor poor
Growth generally begins in early spring [29,53], although plants in the
Southwest may begin growth in winter [32]. Mutton grass flowers from
February to July in New Mexico [47] and from May to August in California
and the Great Plains [23,30]. Seed ripened in late May and June on a
north-central Arizona site [57]. Seed ripens in June or July in
Nebraska [53].
Mutton grass response to fire probably depends upon fire severity. In
Utah juniper-Colorado pinyon of Mesa Verde National Park, Colorado,
mutton grass was present on burn sites representing all stages of
postfire succession except one: an initial postfire community resulting
from a severe fire. Erdman [12,13] sampled vegetation in new (postfire
years 1 to 4), 30-, and 90-year-old burns, and in a Utah juniper-pinyon
woodland that had not burned for 400 years. Mutton grass was not
present on the new burn at postfire year 1, although it is the most
common grass species in Mesa Verde and was present on adjacent unburned
areas. Mutton grass was still absent on the new burn at postfire year
4, the last year of the study. It is likely that mutton grass was
killed by the fire. The fire had killed a 100-year-old stand of
pinyon-juniper, and even sprouting shrubs such as Gambel oak (Quercus
gambelii) showed poor recovery. At postfire year 4, the community was
dominated by forbs and a few exotic perennial grasses that had been
seeded in.
Stand-replacing fires had also occurred on the older burns, but exotic
grasses had not been seeded in after the older fires. Mutton grass was
a dominant component of the vegetation on all older burns and on the
site that had not burned for 400 years. The 30-year-old burn was
codominated by mutton grass and several shrub species. The 90-year-old
burn was dominated by shrubs and had subdominant pinyons and junipers;
mutton grass dominated the herbaceous layer. The site that had not
burned for 400 years was dominated by pinyons and junipers; mutton grass
dominated the herbaceous layer. Mutton grass cover and frequency
percentages on the burn sites were [13]:
% Cover % Frequency
------- -----------
4-yr-old burn 0 0
30-yr-old burn 4-10 88
90-yr-old burn <4 56
400-yr-old burn 4-10 80
Mutton grass recovery after a June 1956 wildfire in shrub live
oak-skunkbush sumac (Quercus turbinella-Rhus trilobata) chaparral in
Arizona was as follows [41]:
1956 1957 1958 1960 1961
Percent cover 1.0 2.0 2.5 4.0 3.0
Production (lbs/acre) trace trace 8 8 8
Tussock graminoid
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".
Mutton grass reproduces from seed, by tillering, and rarely, from short
rhizomes [53]. Both sexual and apomictic populations reproduce from
seed [50].
Lack of pollination is not likely to cause reproductive failure in
mutton grass. Asexual regeneration, by tillering and apomixis, is more
common in mutton grass than is sexual regeneration [48,49,57,58,61].
Most mutton grass populations have a high preponderance of female plants
that produce viable seed without pollination. Averaged over their
range, Soreng [47] estimated that Poa fendleriana ssp. fendleriana
populations are about 85 percent female. Populations of P. f. ssp.
longiligula are mostly or entirely female. Only one male specimen of P.
f. ssp. longiligula has ever been collected in New Mexico [47].
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
15 Black Hills Uplift
16 Upper Missouri Basin and Broken Lands
Mutton grass occurs in open sun [2,60] to partial shade [2,43]. It
tolerates open, dry conditions better than most herbaceous species. In
the Hualapai Mountains of Arizona, it is the only grass that commonly
occurs on open slopes [7]. It may be more common in partial shade on
very dry sites, however. In Colorado pinyon-alligator juniper (Pinus
edulis-Juniperus deppeana) woodland of central Arizona, mutton grass was
more common under alligator juniper than in openings [8]. In northern
Arizona, mutton grass coverage was significantly greater in communities
with 1 to 10 percent pinyon-juniper (Pinus-Juniperus spp.) canopy
coverage than in communities with lesser or greater percentages of tree
cover [2].
In pinyon-juniper communities, mutton grass is common in initial and/or
early seral stages and persists in mature pinyon-juniper woodland
[8,12,13,14].
Sampson [44] classified mutton grass as seral on wheatgrass (Triticeae)
rangelands of the Intermountain West. He described mutton grass as a
component of the mixed-grass-weed stage. This stage is preceded by the
early and late weed stages and followed by the wheatgrass stage.
Mutton grass is frequently described as a component of or dominant in
climax vegetation in sagebrush (Artemisia spp.) and forest habitat
typings [19,26]. In northern Colorado, Francis [18] reported a mountain
big sagebrush/mutton grass habitat type on shallow skeletal soils that
is probably a topoedaphic climax. Forests with mutton grass tend to
have open structure. Romme and others [43] list mutton grass as a
component of dry-site old-growth ponderosa pine forest on the San Juan
National Forest of Colorado.
The currently accepted scientific name of mutton grass is Poa
fendleriana (Steud.) Vasey (Poaceae) [23,25,30,31,33,47,60]. Recognized
subspecies are:
Poa fendleriana subsp. albescens (A.S. Hitchc.) Soreng, mutton grass
Poa fendleriana subsp. fenderliana, skyline bluegrass [33,47]
Poa fendleriana subsp. longiligula (Scribn. & Will.) Soreng, longtongue mutton
grass [30,47]
The genus Poa is extremely uniform, and species determination is
difficult. Mutton grass intergrades and hybridizes with many other Poa
species [48,49,60]. Intergradation with coastline bluegrass (P.
confinis), Wheeler bluegrass (P. nervosa), and Cusick's bluegrass (P.
cusickii) is particularly strong [48]. Welsh and others [60] consider
Cusick's bluegrass synonymous with mutton grass. Based upon chloroplast
DNA analysis and differences in morphologies and mating systems,
however, Soreng [47,48,49] has classified the two taxa as distinct
species. A separate report on Cusick's bluegrass is available in FEIS.
Poa × nematophylla Rydb. is a stable, apomictic taxon probably resulting
from hybridization between mutton grass and a subspecies of Cusick's
bluegrass (P. cusickii ssp. pallida) [49].
Mutton grass has a deep, fibrous root system that provides good soil
erosion control [53]. Use of mutton grass in restoration projects is
limited, however, because mutton grass seed is not commercially
available [10].
Poa fendleriana is a species of grass known by the common name muttongrass. It is native to western North America, where its distribution extends from western Canada to northern Mexico.[1][2]
This species is a perennial grass with small rhizomes. The stems grow up to 70 centimeters tall.[1] The dead sheath bases remain on the plant for a long time.[2] The narrow panicle has up to 8 erect branches crowded with spikelets. One inflorescence may have over 100 spikelets. The plant is dioecious, with male and female flowers on separate plants. Some populations lack male plants, while others are able to reproduce sexually.[1] Asexual reproduction is more common than sexual, and most populations are all female. These produce seed without fertilization by pollen. The sexually reproducing populations are usually found in warmer climates with summer precipitation, while the all-female populations can tolerate colder climates and a wider range of elevations.[2]
This is a common grass in western North America. It grows in many types of habitat, including sagebrush, oak woodlands, pinyon-juniper woodlands, desert grassland, and coniferous forest.
The grass often grows in dry areas, but it can occur in moist habitat, such as riversides. It can grow on many soil types. It occurs mainly on open sites or in partial shade; it does not tolerate the full shade of a closed canopy. It is a dominant plant species in several types of habitat.[2]
This grass is a "good to excellent forage for livestock" and wild animals,[2] feeding cattle, horses, sheep, elk, deer, and pronghorn.[3]
The fibrous root system helps to control erosion of the soil.[2][3] It is tolerant of drought[3] and grazing.[2]
Poa fendleriana is a species of grass known by the common name muttongrass. It is native to western North America, where its distribution extends from western Canada to northern Mexico.
