SPECIES: Poa fendleriana

INTRODUCTORY

SPECIES: Poa fendleriana
AUTHORSHIP AND CITATION:

Howard, Janet L. 1997. Poa fendleriana. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [].

ABBREVIATION:

POAFEN

SYNONYMS:

Poa longiligula
     = P. fendleriana ssp. longiligula [23,25,31]

NRCS PLANT CODE:

POFE
POFEA
POFEF
POFEL

COMMON NAMES:

mutton grass
mutton bluegrass

TAXONOMY:

The currently accepted scientific name of mutton grass is Poa fendleriana (Steud.) Vasey (Poaceae) [23,25,30,31,33,47,60]. Recognized subspecies are:

P. fendleriana ssp. albescens (A.S. Hitchc.) Soreng   mutton grass
P. fendleriana ssp. fenderliana   skyline bluegrass [33,47]
P. fendleriana ssp. 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].

LIFE FORM:

Graminoid

FEDERAL LEGAL STATUS:

No special status

OTHER STATUS:

No entry


DISTRIBUTION AND OCCURRENCE

SPECIES: Poa fendleriana
GENERAL DISTRIBUTION:

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].

ECOSYSTEMS:

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

STATES:

AZ   CA   CO   ID   MT   NE    NV   NM   ND   OR
SD   TX   UT   WA   WY

AB   BC   MB   SK

MEXICO

BLM PHYSIOGRAPHIC REGIONS:

 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

KUCHLER PLANT ASSOCIATIONS:

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

SAF COVER TYPES:

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

SRM (RANGELAND) COVER TYPES:

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

HABITAT TYPES AND PLANT COMMUNITIES:

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]


MANAGEMENT CONSIDERATIONS

SPECIES: Poa fendleriana
IMPORTANCE TO LIVESTOCK AND WILDLIFE:

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].

PALATABILITY:

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


NUTRITIONAL VALUE:

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        
COVER VALUE:

The degree to which mutton grass provides cover for small animals has been rated as follows [11]:

                              UT         WY

Small mammals                fair       good
Small nongame birds          fair       fair
Upland game birds            fair       fair
Waterfowl                    poor       poor
VALUE FOR REHABILITATION OF DISTURBED SITES:

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].

OTHER USES AND VALUES:

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].

OTHER MANAGEMENT CONSIDERATIONS:

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].

BOTANICAL AND ECOLOGICAL CHARACTERISTICS

SPECIES: Poa fendleriana
GENERAL BOTANICAL CHARACTERISTICS:

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].

RAUNKIAER LIFE FORM:

Hemicryptophyte

REGENERATION PROCESSES:

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].

SITE CHARACTERISTICS:

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]

SUCCESSIONAL STATUS:

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.

SEASONAL DEVELOPMENT:

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].


FIRE ECOLOGY

SPECIES: Poa fendleriana
FIRE ECOLOGY OR ADAPTATIONS:

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].

POSTFIRE REGENERATION STRATEGY:

Tussock graminoid


FIRE EFFECTS

SPECIES: Poa fendleriana
IMMEDIATE FIRE EFFECT ON PLANT:

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].

DISCUSSION AND QUALIFICATION OF FIRE EFFECT:

No entry

PLANT RESPONSE TO FIRE:

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  

DISCUSSION AND QUALIFICATION OF PLANT RESPONSE:

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
FIRE MANAGEMENT CONSIDERATIONS:

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].


FIRE CASE STUDIES

SPECIES: Poa fendleriana
FIRE CASE STUDY CITATION:

Howard, Janet L., compiler. 1997. Postfire regeneration of mutton grass on the Fort Valley Experimental Forest, Arizona. In: Poa fendleriana. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [ ].

REFERENCES:

Vose, James M.; White, Alan S. 1987. Processes of understory seedling recruitment 1 year after prescribed fire in an Arizona ponderosa pine community. Canadian Journal of Botany. 65: 2280-2290. [57].

Vose, James M.; White, Alan S. 1991. Biomass response mechanisms of understory species the first year after prescribed burning in an Arizona ponderosa-pine community. Forest Ecology and Management. 40: 175-187. [58].

White, Alan S.; Cook, James E.; Vose, James M. 1991. Effects of fire and stand structure on grass phenology in a ponderosa pine forest. The American Midland Naturalist. 126(2): 269-278. [61].

.
SEASON/SEVERITY CLASSIFICATION:

fall/low severity

STUDY LOCATION:

The study site is located on the Fort Valley Experimental Forest near Flagstaff, Arizona [57,58,61].

PREFIRE VEGETATIVE COMMUNITY:

The study site is in a ponderosa pine (Pinus ponderosa)/mixed grass community. Overstory structure of the community prior to the fires was a mosaic of patches, each dominated by one of three overstory strata: saplings, pole-sized trees, or sawtimber trees [57,58]. Average density, diameter, and basal area of ponderosa pine in each overstory stratum was [58]:


                Density         Diameter        Basal area           
               _________        ________        __________
sapling        10,070/ha         4.5 cm         15/sq m/ha
pole            1,730/ha         15 cm          31/sq m/ha
sawtimber        120/ha          63 cm          35/sq m/ha
The grass understory was a mixture of mutton grass (Poa fendleriana), mountain muhly (Muhlenbergia montana), and bottlebrush squirreltail (Elymus elymoides). Biomass of mutton grass and mountain muhly in open sawtimber was approximately equal (57 kg/ha); biomass of bottlebrush squirreltail was less (40 kg/ha) [58]. Wheeler's thistle (Cirsium wheeleri) and Wright's deervetch (Lotus wrightii) were important understory forbs. Fendler's ceanothus (Ceanothus fendleri) and Wood's rose (Rosa woodsii var. ultramontana) were also present [57].

 

TARGET SPECIES PHENOLOGICAL STATE:

Mutton grass had dispersed its seed and was dormant at the time of the fires [61].

SITE DESCRIPTION:

The study site had been fenced prior to the study to exclude livestock and was relatively undisturbed [58,61]. Elevation at the study site is approximately 6,900 feet (2100 m). Soils are a Brolliar stony clay loam. Annual precipitation ranges from 109 to 163 inches (430-640 mm) and averages 127 inches (500 mm). Precipitation patterns are scattered snowfall and rain in winter months, drought in May and June, and frequent rains in July and August. Daily mean temperatures range from 23 to 67 degrees Fahrenheit (-5 to 17 oC). July has the highest monthly mean temperature (61 degrees Fahrenheit (16 oC)), and January has the lowest (25 degrees Fahrenheit (-4 oC)). Precipitation for the year following the study was above average [57,58,61].

Fire history of the area suggests that fires burned at approximate 2-year intervals until the late 1800's. Fires have been excluded since that time [58].

FIRE DESCRIPTION:

Study plots were prescribe burned on 2 consecutive days in late October 1982. Mean air temperatures were 64 and 57 degrees Fahrenheit (18 and 14 oC). Relative humidity was 21 percent on both days. Strip headfires and backfires were used. Fires were maintained in the understory. The fires consumed 25 to 95 percent of the fuel load and smoldered for several days [57,58]. Two site types were defined in the sawtimber stratum: sites between canopies (Open ST) with minimal litter, and sites below canopies (Below ST) with thick litter accumulations [57]. Based upon heat-yield data and observations, fire severity was ranked: below-canopy sawtimber > pole > sapling > open-canopy sawtimber [58]. Most understory plants in sawtimber patches were between canopies (Open ST), where heat yield averaged only 1,600 kJ/sq m. Fire behavior and fuel data are presented below [57].



                            Open ST  Below ST   Pole    Sapling

Fire behavior                                                          
  Intensity (kW/m)                                                     
    backfires               5         NA        14       17 
    headfires               NA        NA        346      294 
  Rate of spread (m/min)                                               
    backfires               0.2       NA        0.2      0.3
    headfires               NA        NA        4.5      7.6
Total heat yield (kJ/sq m)  1,600     NA        42,082   15,866 
Prefire fuel load (Mg/ha)   17.1      145.9     46.2     30.5
Fuel consumption (%)        25        95        55       33 

FIRE EFFECTS ON TARGET SPECIES:

Neither seedlings nor mature mutton grass plants occurred in sufficient density on sapling and below-canopy sawtimber plots to warrant analysis [58]. Data are given for pole and open sawtimber sites only.

Postfire seedling establishment: To help determine if mutton grass or other herbaceous species were present in the soil seedbank, soil samples were collected from each forest stratum before the fires. The samples were spread out on vermiculite in the greenhouse and watered. Mutton grass seedlings did not emerge from soil samples from any of the forest strata [57].

Seed rain was collected in seed traps on open sawtimber sites for the first postfire year. Nearly all mutton grass seed dispersed in June. Total mutton grass seed rain (seeds/sq m) for 1 year on burned and unburned control sawtimber sites was [57]:

                       Burn             Control
                       -----            -------
                       87.31             54.32 
The first June after the fires, density of mutton grass seedlings was 0.1 seedling per square meter on open sawtimber and pole plots. Mutton grass seedlings were not found on below-sawtimber and sapling plots. Density of mutton grass seedlings remained unchanged on plots of all strata through at least the first October after the fires [57].

Fire effect on mature plants: Burning had little effect on residual mutton grass. At postfire year 1, biomass and density of mutton grass on burned and unburned open sawtimber plots were very similar. Biomass was significantly reduced on burned pole plots, but density was not. Biomass (kg/ha) and density (plants/sq m) of residual mutton grass plants in the first postfire fall (Oct. and Nov. 1983) were [58]:
                   Biomass                   Density
                _________________________  ______________________
                burn         control       burn        control
open sawtimber  54.64 (4.81) 56.06 (7.73)  1.81 (0.03) 1.92 (0.04)
pole            3.97 (0.56)* 5.08 (0.92)   0.46 (0.12) 0.75 (0.20)
__________________________________________________________________
Values are adjusted means (standard errors) from analysis of
covariance.*Significant (P<0.05) difference between burn and
control
The number of mutton grass plants producing seed did not change after fire. There were no significant differences in the number of mutton grass plants reaching the seed stage between burned and unburned plots in postfire years 1 and 2. Percentage of plants reaching the seed stage follows [61]. Sample size is indicated in parentheses.

            Pole             Sawtimber    
       ________________   ________________
Year   Burned  Unburned   Burned  Unburned  Chi-sq  P-value
___________________________________________________________
1983   29 (7)  38 (8)     74 (19)  44 (18)  6.20    0.102
1984   42 (12) 63 (8)     70 (20)  59 (22)  2.53    0.469

FIRE MANAGEMENT IMPLICATIONS:

The prescribed fall fires had little effect on mutton grass. In open sawtimber, mortality rates in the first postfire year were not significantly different between burned and unburned plots (4% on burned and 0% on controls). Biomass, density, and number of plants producing seed after fire were similar on burned and unburned open sawtimber plots [57,58,61]. On pole plots, density was unaffected by fire. Biomass of residual plants was significantly greater on unburned pole plots than on burned pole plots. When biomass of seedlings and residual plants on pole plots was combined, however, total biomass differences were insignificant between burned and unburned plots. Lack of fire effect may be because plants had senesced and were dormant when burned [61].

This study indicates that mutton grass will be unharmed or only slightly reduced by prescribed fall burning in southwestern ponderosa pine understories. Tillering was the most important mechanism of postfire mutton grass regeneration. Although some mutton grass seedlings established on burned plots, they did not establish in large numbers. Seed production was unaffected by fire.


Poa fendleriana: References


1. Andariese, Steven W. 1982. Time-response graphs for understory production following fall prescribed burning in Arizona ponderosa pine on basalt soils. Flagstaff, AZ: Northern Arizona University. 42 p. Thesis. [20307]

2. Arnold, Joseph F.; Jameson, Donald A.; Reid, Elbert H. 1964. The pinyon-juniper type of Arizona: effects of grazing, fire and tree control. Production Research Report No. 84. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 28 p. [353]

3. Baker, William L. 1984. A preliminary classification of the natural vegetation of Colorado. The Great Basin Naturalist. 44(4): 647-676. [380]

4. Baxter, Clay. 1977. A comparison between grazed and ungrazed juniper woodland. In: Aldon, Earl F.; Loring, Thomas J., technical coordinators. Ecology, uses, and management of pinyon-juniper woodlands: Proceedings of the workshop; 1977 March 24-25; Albuquerque, NM. Gen. Tech. Rep. RM-39. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 25-27. [17255]

5. Beath, O. A.; Hamilton, J. W. 1952. Chemical composition of Wyoming forage plants. Bull. No. 311. Laramie, WY: University of Wyoming, Agricultural Experiment Station. [5527]

6. 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]

7. Butterwick, Mary; Parfitt, Bruce D.; Hillyard, Deborah. 1992. Vascular plants of the northern Hualapai Mountains, Arizona. Journal of the Arizona-Nevada Academy of Science. 24-25: 31-49. [18327]

8. Clary, Warren P.; Morrison, Douglas C. 1973. Large alligator junipers benefit early-spring forage. Journal of Range Management. 26(1): 70-71. [645]

9. Currie, P. O.; Reichert, D. W.; Malechek, J. C.; Wallmo, O. C. 1977. Forage selection comparisons for mule deer and cattle under managed ponderosa pine. Journal of Range Management. 30(5): 352-356. [4697]

10. Dietz, Donald R.; Nagy, Julius G. 1976. Mule deer nutrition and plant utilization. In: Workman; Low, eds. Mule deer decline in the West: A symposium; [Date of conference unknown]; [Location of conference unknown]. [Logan], UT: College of Natural Resources, Utah Agriculture Experiment Station: 71-78. [6909]

11. Dittberner, Phillip L.; Olson, Michael R. 1983. The plant information network (PIN) data base: Colorado, Montana, North Dakota, Utah, and Wyoming. FWS/OBS-83/86. Washington, DC: U.S. Department of the Interior, Fish and Wildlife Service. 786 p. [806]

12. Erdman, James A. 1970. Pinyon-juniper succession after natural fires on residual soils of Mesa Verde, Colorado. Brigham Young University Science Bulletin. Biological Series. 11(2): 1-26. [11987]

13. Erdman, James Allen. 1969. Pinyon-juniper succession after fires on residual soils of the Mesa Verde, Colorado. Boulder, CO: University of Colorado. 81 p. Dissertation. [11437]

14. Everett, Richard L.; Sharrow, Steven H. 1983. Response of understory species to tree harvesting and fire in pinyon-juniper woodlands. In: Monsen, Stephen B.; Shaw, Nancy, compilers. Managing Intermountain rangelands--improvement of range and wildlife habitats: Proceedings of symposia; 1981 September 15-17; Twin Falls, ID; 1982 June 22-24, Elko, NV. General Technical Report INT-157. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station: 62-66. [897]

15. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905]

16. Fergus, Ernest N.; Buckner, Robert C. 1973. The bluegrasses and redtop. In: Forage scienes--grassland agriculture. [Place of publication unknown]: [Publisher unknown]: 243-253. On file with: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station, Fire Sciences Laboratory, Missoula, MT. [25523]

17. Ffolliott, Peter F.; Clary, Warren P.; Larson, Frederic R. 1977. Effects of a prescribed fire in an Arizona ponderosa pine forest. Res. Note RM-336. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 4 p. [4750]

18. Francis, Richard E. 1983. Sagebrush-steppe habitat types in northern Colorado: a first approximation. In: Moir, W. H.; Hendzel, Leonard, tech. coords. Proceedings of the workshop on Southwestern habitat types; 1983 April 6-8; Albuquerque, NM. Abluquerque, NM: U.S. Department of Agriculture, Forest Service, Southwestern Region: 67-71. [955]

19. Francis, Richard E.; Aldon, Earl F. 1983. Preliminary habitat types of a semiarid grassland. In: Moir, W. H.; Hendzel, Leonard, tech. coords. Proceedings of the workshop on Southwestern habitat types; 1983 April 6-8; Albuquerque, NM. Albuquerque, NM: U.S. Department of Agriculture, Forest Service, Southwestern Region: 62-66. [956]

20. 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]

21. Gonella, Michael P.; Neel, Maile C. 1995. Characterizing rare plant habitat for restoration in the San Bernardino National Forest. In: Roundy, Bruce A.; McArthur, E. Durant; Halley, Jennifer S.; Mann, David K., compilers. Proceedings: wildland shrub and arid land restoration symposium; 1993 October 19-21; Las Vegas, NV. Gen. Tech. Rep. INT-GTR-315. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 81-93. [24830]

22. Gould, Frank W.; Shaw, Robert B. 1983. Grass systematics. 2d ed. College Station, TX: Texas A&M University Press. 397 p. [5667]

23. Great Plains Flora Association. 1986. Flora of the Great Plains. Lawrence, KS: University Press of Kansas. 1392 p. [1603]

24. Haisley, James R. 1984. The effects of presecribed burning on four aspen-bunchgrass communities in northern Arizona. Flagstaff, AZ: Northern Arizona University. 47 p. Thesis. [27667]

25. 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]

26. Hanks, Jess P.; Fitzhugh, E. Lee; Hanks, Sharon R. 1983. A habitat type classification system for ponderosa pine forests of northern Arizona. Gen. Tech Rep. RM-97. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 22 p. [1072]

27. Harper, K. T.; Sanderson, S. C.; McArthur, E. D. 1992. Riparian ecology in Zion National Park, Utah. In: Clary, Warren P.; McArthur, E. Durant; Bedunah, Don; Wambolt, Carl L., compilers. Proceedings--symposium on ecology and management of riparian shrub communities; 1991 May 29-31; Sun Valley, ID. Gen. Tech. Rep. INT-289. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 32-42. [19092]

28. Harrington, H. D. 1964. Manual of the plants of Colorado. 2d ed. Chicago: The Swallow Press Inc. 666 p. [6851]

29. Herzman, Carl W.; Everson, A. C.; Mickey, Myron H.; [and others]. 1959. Handbook of Colorado native grasses. Bull. 450-A. Fort Collins, CO: Colorado State University, Extension Service. 31 p. [10994]

30. Hickman, James C., ed. 1993. The Jepson manual: Higher plants of California. Berkeley, CA: University of California Press. 1400 p. [21992]

31. Hitchcock, C. Leo; Cronquist, Arthur. 1973. Flora of the Pacific Northwest. Seattle, WA: University of Washington Press. 730 p. [1168]

32. Humphrey, Robert R. 1960. Arizona range grasses: Description--forage value--management. Tucson, AZ: University of Arizona, Agricultural Experiment Station. 104 p. [5004]

33. Kartesz, John T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. Volume II--thesaurus. 2nd ed. Portland, OR: Timber Press. 816 p. [23878]

34. Komarkova, Vera. 1986. Habitat types on selected parts of the Gunnison and Uncompahgre National Forests. Final Report Contract No. 28-K2-234. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 270 p. [1369]

35. Koniak, Susan. 1985. Succession in pinyon-juniper woodlands following wildfire in the Great Basin. The Great Basin Naturalist. 45(3): 556-566. [1371]

36. Kuchler, A. W. 1964. United States [Potential natural vegetation of the conterminous United States]. Special Publication No. 36. New York: American Geographical Society. 1:3,168,000; colored. [3455]

37. Marquiss, Robert; Lang, Robert. 1959. Vegetational composition and ground cover of two natural relict areas and their associated grazed areas in the Red Desert of Wyoming. Journal of Range Management. 12: 104-109. [1529]

38. Moir, William H.; Ludwig, John A. 1979. A classification of spruce-fir and mixed conifer habitat types of Arizona and New Mexico. Res. Pap. RM-207. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 47 p. [1677]

39. Mooney, Melissa Jane. 1985. A preliminary classification of high-elevation sagebrush-grass vegetation in northern and central Nevada. Reno, NV: University of Nevada. 123 p. Thesis. [1689]

40. National Academy of Sciences. 1971. Atlas of nutritional data on United States and Canadian feeds. Washington, DC: National Academy of Sciences. 772 p. [1731]

41. Pase, Charles P.; Pond, Floyd W. 1964. Vegetation changes following the Mingus Mountain burn. Res. Note RM-18. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 8 p. [5700]

42. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. [2843]

43. Romme, William H.; Jamieson, David W.; Redders, Jeffery S.; [and others]. 1992. Old-growth forests of the San Juan National Forest in southwestern Colorado. In: Kaufmann, Merrill R.; Moir, W. H.; Bassett, Richard L., technical coordinators. Old-growth forests in the southwest and Rocky Mountain regions: Proceedings of a workshop; 1992 March 9-13; Portal, AZ. Gen. Tech. Rep. RM-213. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 154-165. [19050]

44. Sampson, Arthur W. 1919. Plant succession in telation to range management. Bulletin No. 791. Washington, DC: U.S. Department of Agriculture. 76 p. [3787]

45. Saunders, Jack K., Jr. 1955. Food habits and range use of the Rocky Mountain goat in the Crazy Mountains, Montana. Journal of Wildlife Management. 19(4): 429-437. [484]

46. Shiflet, Thomas N., ed. 1994. Rangeland cover types of the United States. Denver, CO: Society for Range Management. 152 p. [23362]

47. Soreng, Robert J. 1985. Poa L. in New Mexico, with a key to middle and southern Rocky Mountain species (Poaceae). The Great Basin Naturalist. 45(3): 395-422. [2198]

48. Soreng, Robert J. 1990. Chloroplast-DNA phylogenetics and biogeography in a reticulating group: study in Poa (Poaceae) American Journal of Botany. 77(11): 1383-1400. [27549]

49. Soreng, Robert J. 1991. Systematics of the "Epiles" group of Poa (Poaceae) Systematic Botany. 16(3): 507-528. [27716]

50. Soreng, Robert J.; Van Devender, Thomas R. 1989. Late quaternary fossils of Poa fendleriana (muttongrass): Holocene expansions of apomicts. The Southwestern Naturalist. 34(1): 35-45. [9320]

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. Stubbendieck, J.; Nichols, James T.; Roberts, Kelly K. 1985. Nebraska range and pasture grasses (including grass-like plants). E.C. 85-170. Lincoln, NE: University of Nebraska, Department of Agriculture, Cooperative Extension Service. 75 p. [2269]

53. Stubbendieck, James; Hatch, Stephan L.; Butterfield, Charles H. 1992. North American range plants. 4th ed. Lincoln, NE: University of Nebraska Press. 493 p. [25162]

54. Tiedeman, James A.; Francis, Richard E.; Terwilliger, Charles, Jr.; Carpenter, Len H. 1987. Shrub-steppe habitat types of Middle Park, Colorado. Res. Pap. RM-273. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 20 p. [2329]

55. U.S. Department of Agriculture, Forest Service, Rocky Mountain Region. 1983. Plant associations (habitat types) of Region 2.,3rd ed. Lakewood, CO. 224 p. [2385]

56. U.S. Department of Agriculture, Soil Conservation Service. 1994. Plants of the U.S.--alphabetical listing. Washington, DC: U.S. Department of Agriculture, Soil Conservation Service. 954 p. [23104]

57. Vose, James M.; White, Alan S. 1987. Processes of understory seedling recruitment 1 year after prescribed fire in an Arizona ponderosa pine community. Canadian Journal of Botany. 65: 2280-2290. [4053]

58. Vose, James M.; White, Alan S. 1991. Biomass response mechanisms of understory species the first year after prescribed burning in an Arizona ponderosa-pine community. Forest Ecology and Management. 40: 175-187. [15570]

59. Wallmo, O. C.; Gill, R. Bruce. 1973. Middle Park deer study: physical characteristics and food habits. In: Federal Aid Completion Report: Project W-38-R-27: WP-14: J4. Denver, CO: Colorado Division of Wildlife: 83-103. [2445]

60. Welsh, Stanley L.; Atwood, N. Duane; Goodrich, Sherel; Higgins, Larry C., eds. 1987. A Utah flora. The Great Basin Naturalist Memoir No. 9. Provo, UT: Brigham Young University. 894 p. [2944]

61. White, Alan S.; Cook, James E.; Vose, James M. 1991. Effects of fire and stand structure on grass phenology in a ponderosa pine forest. The American Midland Naturalist. 126(2): 269-278. [16885]



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