Forage Values on a green fescue ( viridula Vasey), also a bunch- grass, is encountered with Letterman and subal- Mountain Grassland-Aspen Range pine needlegrasses (Stipa lettermani Vasey and S. columbiana Macoun) and mountain brome (Bro- in Western Colorado1 mus carinatus Hook. and Am.) (Pickford and Reid, 1942), all of which commonly occur in western HAROLD A. PAULSEN, JR. .

Principal Ecologist, Many cattle graze the mountain grassland and Rocky Mountain Forest and Range Experiment Station aspen types of western Colorado. Cool climate, Fort Collins, Colorado2 comparatively gentle topography, and nutritious forage make them highly prized for summer graz- ing. As an aid to management, information is pre- Highlight sented here on the quantity, relative preference, The productivity, relative preference, and nutritive value and nutritive value of the important forage species. of Idaho fescue makes it the most valuable forage species In addition to their grazing value, the types pro- on summer cattle range on Black Mesa in western Colorado. vide ample watershed protection when not abused Forbs that were abundant, high in nutritive value, and (Turner and Dortignac, 1954). As a consequence selected by cattle were aspen fleabane, aspen peavine, and agoseris in the mountain grassland type. sedge was the of past improper use, however, Thurber fescue has major forage species in the aspen type. been replaced by less desirable species in many cases (Costello, 1954). Range improvement on West of the Continental Divide in the southern mountain cgrassland sites may require a number of , open parks within the spruce- years (Strickler, 196 1). fir forests are occupied by a diverse herbaceous vegetation (Fig. 1). Intermingled are sites domi- Study Area and Methods nated by aspen (Po~uZus tremuloides Michx.) that Black Mesa is a segment of the Colorado Plateau at the support a luxuriant understory of grasses and forbs. western extremity of the Elk Mountains, approximately 100 Thurber fescue (Festuca thurberi Vasey), a large miles southeast of Grand Junction, Colorado. Herbaceous bunchgrass, often characterizes the general aspect vegetation is often dominated by Thurber fescue, but some of the parks as well as the aspen understory. Hence, sites are typified by nearly pure stands of hairy goldaster the grass-forb openings frequently are categorically (Chrysopsis villosa (Pursh) Nutt. ex DC), a species of little referred to as Thurber fescue grasslands. Langen- forage value. Numerous other plant communities may be heim (1962) described the “Festuca thurberi grass- distinguished between these two extremes. lands” of the Crested Butte area in western Colo- Elevations on Black Mesa range from 9,000 to 10,500 rado as a community with a wide elevational range ft. The mesa is capped by a layer of volcanic material, principally Piedra rhyolite and Huerta andesite. The that is found on deep soils and xeric exposures. surface is dissected by intermittent streams which drop Thurber fescue has been reported at elevations of steeply from the rim to the major drainages which bound 5,000 to 12,000 ft from southern , Colo- the mesa: Crystal Creek on the northwest, Curecanti Creek rado, northern (U.S. Forest Service, on the southeast, and the Gunnison River on the southwest. 1937), and westward in the Abajo Mountains of The loamy soils are generally fertile and productive, and Utah3 and the Graham Mountains of range in thickness from a few inches to 3 ft or more. They (Kearney and Peebles, 1942). grade into a tighter subsoil and unconsolidated rock. The In many respects these grasslands are similar to solum may be more than 8 ft thick. Surface soils are other high-elevation grasslands of the mountainous relatively high in infiltration, water-holding capacities, and West. For example, in the Big Horn Mountains in resistance to erosion. Precipitation on the mesa is heaviest in late winter or Wyoming, grassland openings are dominated by spring; snow contributes approximately 3h of the total. Idaho fescue (Festuca idahoensis Elmer) (Hurd, Rainfall is least in June, and August is the wettest summer 1961), which is an important species in western month. Although rainfall intensity may be high during Colorado. In eastern Oregon and Washington, thunderstorms, little moisture is lost through surface runoff. Yearly records of herbage production from 1956 to 1965 l Received April 25, 1968; accepted for publication August have been obtained from permanent sampling points within 12, 1968. two range units grazed by cattle. The units are 132 and 2Forest Service, U. S. Department of Agriculture, with head- 394 acres in size. Grassland and aspen comprise 80 and 98% quarters at Fort Collins, Colorado, in cooperation with of the two units, and spruce-fir forest the remainder. Colorado State University. Author is currently Assistant Grassland occupies 57% of the first unit and 46% of the Director, Range and Wildlife Habitat Research, Forest second. Service, Washington, D. C. Thirty samples in the grassland and 10 in the aspen were 3 Ellison, L. Festuca thurberi grassland, Indian Creek established according to a stratified random sampling pro- Abajo Mts., . Unpubl. data, Intermountain Forest and Range Experiment Station, U. S. Forest Service, cedure. Preliminary tests had shown this to be adequate to Ogden, Utah, sample total grass production on an air dry basis within

102 MOUNTAIN GRASSLAND-ASPEN RANGES 103

40

DEPTHS

- O-3 Inches 35 ---- 3-6 Inches -‘-‘- 9-12 inches ...... 15-18 inches

30

FIG. 1. Thurber fescue grassland on Black Mesa in western Colorado.

15% of the mean with a probability of 95%. At each sampling location, three systematically spaced 2.5-ft2 plots were marked along a 50-ft transect. FIG. 2. Average soil moisture at four depths and precipitation Production of individual species on each plot was esti- 1963-65. Black Mesa Experimental Forest and Range, Colo- mated between mid-July and- early August b; the weight- rado. estimate method (Pechanec and Pickford, 1937a). Double sampling was employed to provide a basis for adjusting the tures averaged above freezing. Temperatures oc- estimated values and for converting herbage production to an air dry basis. Separate ratios were determined for ad- casionally fell well below average for one to several justments of the major species; average ratios computed days and noticeably curtailed growth even in these from these were applied to the minor species. months. Utilization was estimated on the permanent plots by the Herhage Growth.-Very soon after snowmelt and ocular estimate by plot method (Pechanec and Pickford, usually in June, rapid herbage growth began. Herb- 193713). Estimates- on the grasses were made annually in age production reached its maximum by late July late September or early October at the end of the grazing approximately 6 to 8 weeks after snowmelt. Un- season. Intraseasonal utilization estimates were made on usually heavy snow cover or cool weather some- all species between 1961 and 1963. times delayed peak production until August. Samples of the major forage species were clipped By mid-July most herbaceous species were flow- periodically through the grazing seasons in 1962 and 1963. Dried and ground samples were analyzed by standard ering. Seeds ripened and were disseminated during proximate analysis procedures for crude protein, calcium, late August and September. Limited vegetative and phosphorus (A ssociation of Official Agricultural growth was frequently observed until October, Chemists, 1960). especially on the grasses. Forbs had largely disap- peared from the standin, u herbaceous cover by this Results and Discussion time. Grasses averaged 53yo moisture when sampled Environmental Relations.-Precipitation averaged for production; the several species ranged from 44 6.68 inches from June through September, and to 65yo. The forbs varied from 60 to 78yo mois- 28.83 inches between October 1 and September 30 ture; individual species contained as high as 85%. for the study period. Because of inaccessibility of Parry rabbitbrush (Chrysothamnus parryi (A. Gray) the area during most of the rest of the year, only Greene), the most abundant shrub in the grassland, total precipitation was recorded for the period Od- averaged 67yo moisture. Turner4 has shown a sig- tober- through May. nificant relationship in moisture content among Following snowmelt the soil on Black Mesa is the major species on Black Mesa. saturated. Soil moisture rapidly declined in June (Fig. 2) and below 1 ft there was little recovery during’ the summer despite increased precipitation 4Turner, George T. Plant moisture relations as a basis in July. In the surface-foot of soil, moisture fluc- for determining moisture content of rangeland herbage. Unpubl. data, Rocky Mountain Forest and Range Ex- tuated in response to the current precipitation. periment Station, U. S. Forest Service, Fort Collins, From June through August, minimum tempera- Colorado. 104 PAULSEN

Table 1. Herbage production (lb/acre, air dry) on moun- which yielded slightly less than half the amount tain grassland and aspen ranges from 1955 to 1965, furnished by geranium. Three forb species-aspen Black Mesa Experimental Forest and Range, Colorado. fleabane (Erigeron macranthus Nutt.), aspen pea- vine (Lathyrus leucanthus Rydb.), and agoseris Thurber fescue grassland range Aspen range Yeai- (Agoseris spp.)-together produced an average of Grasses’ Forbs Shrubs Total Grasses1 Forbs Shrubs Total 190 lb/acre, while 35 other species furnished 258 lb/acre. Of these only beauty cinquefoil (Potentilla 1955 920 520 42 1,482 442 311 2 755 1956 512 527 81 1,120 342 279 2 623 pulcherrima Lehm.) was consistent and appreciable; 1957 529 865 83 1,477 204 397 2 603 it contributed 3.4% to the total production. 1958 584 826 66 1,476 232 548 5 785 1959 586 701 98 1,385 214 375 3 592 Important species in the aspen type differ from 1960 484 677 116 1,277 188 389 5 582 those in the grassland, as shown below ranked ac- 1961 622 1,069 94 1,785 336 511 5 852 1962 751 814 100 1,665 289 519 10 818 cording to percent composition. 1963 683 683 67 1,433 349 692 25 1,066 1964 510 546 48 1,104 173 417 23 613 Grass, grass-like 37.8 1965 828 912 73 1,813 310 526 20 856 Elk sedge (Carex geyeri Boott.) 27.7 Avg 637 740 79 1,456 280 451 9 740 Bromegrass 3.2

‘Includes sedges. Thurber fescue 3.2 Slender wheatgrass 1.6 Others 2.1 Total Production .-Herbage expressed as air dry Shrubs 1.3 Forbs 60.9 pounds per acre averaged 1,456 lb on the grassland Loveroot (Ligusticum porteri Coult. & Rose) 10.9 sites (Table 1). At the peak of production the grass- Aspen peavine 8.0 land sites have a conspicuous forb aspect. Grass Meadowrue (Thalictrum dasycarpum Fisch. & Lall.) 5.9 and grass-like species contributed 44% of the total Strawberry (Fruguria gluuca (S. Wats.) Rydb.) 4.6 herbage, forbs 51%, and shrubs 5%. Osmorhiza (Osmorhiza obtusa (Coult. & Rose) Herbage production is relatively more stable Fernald) 3.0 than on many ranges at lower elevations, which are Geranium 3.0 often subject to more variable precipitation. For Bedstraw (G&urn boreale L.) 2.6 Others 22.9 example, in 7 out of 11 years, total production was within 15% of the mean. Variations must be rec- Fifteen species are grasses or grass-like, 26 are forbs, ognized in the management of these ranges, how- and 2 are shrubs. Elk sedge furnished the most for- ever; production ranged from 23 y0 above average age in the aspen. As in the grassland, slender to 27% below during the study period. In succes- wheatgrass, bromegrass, and Thurber fescue were sive years production has increased more than 700 persistent contributors. Only loveroot of the forbs lb/acre, but decreases between two successive years produced more than 80 lb/acre; 19 others provided have been less pronounced. from 0.1 to 2.9%. Often a species may have been Under the aspen canopy, herbaceous production especially abundant at a certain location, but lacked averaged approximately half as much as on the constancy in the understory. grassland sites. It was within 15% of the average From the annual appraisal of herbage produc- in only 4 of 11 years. Forbs averaged 61 y0 of the tion, stocking records, and utilization estimates of total production, and most of the remainder of the Idaho fescue, (which averaged 38%), the grassland herbage was grasses and grass-like species. grazing capacity was computed to be between 1.4 Production of Species.-Idaho fescue was the pri- and 1.7 animal unit months/acre.5 The coefficient mary forage producer on the grassland portions of of multiple determination of the relationship was the two range units. This species produced almost 0.80. The projection is based upon the method twice as much as Thurber fescue and Letterman suggested by Reid et al. (1963). needlegrass, each of which contributed about 8% The two units are relatively small, fenced areas, of the total herbage. Other grasses that furnished all parts of which are readily accessible and rather between 3 and 4% of the herbage included slender uniformly grazed. Consequently, one should be wheatgrass (Agropyron trachycaulum (Link) Malte), wary of extrapolating these data to other areas of and the bromegrasses (Bromus carinatus and B. Thurber fescue grassland without adequate testing anomalus Rupr.). Nine other grasses furnished to assess the relationship of utilization, production, the remainder. Parry rabbitbrush furnished 5.4% and stocking. They are of interest, however, in of the herbage. Fremont geranium (Geranium fre- that they indicate a rather high grazing capacity for montii Torr.) was second to Idaho fescue in pro- Thurber fescue grasslands under intensive manage- duction of herbage. During the study period, nearly ment. 14% of the herbage was composed of this one spe- cies, which has little, if any, forage value. The sec- “An animal unit in this study was a 500- to 700-lb steer or ond highest forb contributor was hairy goldaster, heifer. MOUNTAIN GRASSLAND-ASPEN RANGES 105

Table 2. Production, cattle preference, and relative Table 3. Production, cattle preference, and relative forage value for forage species on mountain grassland forage value for forage species on aspen ranges, Black ranges, Black Mesa Experimental Forest and Range, Mesa Experimental Forest and Range, Colorado. Colorado. Percent utilization by Production number of days grazed Forage Species (lb/acre) value1 21 38 57 78

Grasses and grass -like

Elk sedge 205 2 5 8 9 1.00 Fringed brome 24 4 8 13 17 .22 Mountain brome 10 3 14 22 .11 Thurber fescue 24 3 12 18 7 .ll Slender wheatgrass 9 4 6 24 11 .06 Others 5

Forbs

Meadowrue 44 1 6 15 .39 False sunflower 14 10 11 37 .28 Aspen peavine 59 2 3 7 .22 Fireweed (Epilobium 10 4 6 18 .11 angustifolium L. ) Thistle (Cirsium 11 4 14 13 106 centaureae (Rydb. ) K. Schum) Northern bedstraw 17 1 2 6 .06 (Galium boreale L. ) Butterweed groundsel 21 1 5 .06 (Senecio serra Hook.) -- Others 279 ’ Ranking based upon the product of final utilization and production divided by the product obtained for Idaho fescue. Species llsted were present on ’ Ranking based upon the product of final utilization and production divided at least 5’$ of the plots. by the product obtained for elk sedge. Species listed were present on at least 5% of the plots.

Cattle Prefere?zce.6-For 3 years, estimates of per- age on Black Mesa. The value of aspen fleabane, cent utilization of species on the grassland and as- for instance, which furnished 90 lb/acre of herb- pen sites were obtained 17 to 2 1 days, 34 to 40 days, age, is significant in the grazing resource. In addi- 54 to 61 days, and 75 to 82 days after grazing began. tion, aspen peavine and agoseris furnish appreciable Grasses and grass-like species only were estimated quantities of forage and are highly preferred by in the final period because of the disappearance of cattle. The most highly preferred species was false the forbs late in the season. The relative ranking sunflower (HeZiantheZZa quinquinewis (Hooker) of the primary forage species based upon percent A. Gray) which was utilized an average of 44% use and production of herbage is shown in Tables after 56 days of grazing. Other forbs utilized in ex- 2 and 3. cess of 10% included silverweed cinquefoil (Poten- Idaho fescue must be recognized as the primary tilla anserina L.), aster (Aster spp.), and bluebell forage species in the grassland on Black Mesa. This (Campanula rotundifolia L.). species was also one of the most preferred species Certain species are grazed early but then receive wherever it occurred on the Big Horn Mountains little additional utilization the rest of the season. (Hurd and Pond, 195s). Not only does it rank high For example, dandelion (Taraxacum officinale in preference, but in combination with production Wiggars) was grazed an average of 8% after 18 days it rated more than twice as high as the next closest but only 10% after 56 days. In contrast, utilization species, Letterman needlegrass. Thurber fescue, of aspen fleabane increased steadily through the which is sometimes considered to be of doubtful season. forage value, does contribute substantially to the The most striking changes in utilization of the forage resource as indicated by its third place rat- grasses occur after the forbs die back with freezing ing. Kentucky bluegrass (Pea fwatensis L.) was weather. Up to 56 days, however, utilization of the more heavily grazed than other grasses present on forbs and grasses is very similar. Kentucky blue- at least 5% of the plots; due to its limited produc- grass and false sunflower were grazed noticeably tion, however, it ranked low in the relative forage more than others of their class up to this time. Be- value rating. Other species which were 20 to 25oi’, cause of greater production, preferred grasses con- utilized by the end of the grazing season included tribute appreciably more to the animal’s diet than prairie junegrass (KoeZeria cristata (L.) Pers.), sedge, do the preferred forbs. Nevertheless, the palatable and subalpine needlegrass. forbs are very important components of the forage Certain forbs contribute appreciably to the for- resource, and must be recognized in management of these ranges. 6As used here, preference is a reflection of all factors that operate to determine whether and to what degree the Forage use was generally less in the aspen type forage are consumed by grazing animals. than in the grassland. Elk sedge was not heavily 106 PAULSEN

Table 4. Percentage crude protein, phosphorus, and ing 1962 and 1963 are reported in Table 4. Pre- calcium of major forage species, 1962-63, Black Mesa cipitation during rapid growth in June and July Experimental Forest and Range, Colorado. was similar in these years; 1.68 inches in 1962 and 1.52 inches in 1963. When first collected in July, Phenological development Nutrient and species the of Idaho fescue were fully ex- Leaves Flower - Seed ripening Regrowth; only ing and dispersal dormancy panded but had not reached anthesis. Thurber fescue and Letterman needlegrass were similar to CRUDE PROTEIN: Idaho fescue, but slender wheatgrass and brome- Idaho fescue 9.8 9.0 7.0 Thurber fescue 9.8 8.6 6. 1 grass were somewhat farther advanced. Elk sedge, Letterman needlegrass 11.8 9.6 7.0 Slender wheatgrass 9.5 11.9 5.5 on the other hand, had already flowered and was Bromegrass 11.4 11.4 7.1 collected only in a vegetative stage. Elk sedge IO. 2 Aspen fleabane 18.1 14.8 12.0 11.0 The three forbs which furnish appreciable Agoseris 15.1 11.6 11.2 amounts of forage were collected regularly for Aspen peavine 21.7 21.5 17.8 analysis. Aspen peavine and agoseris were in bloom PHOSPHORUS: when first collected at the time grazing began. As- Idaho fescue .21 .15 . 12 Thurber fescue .19 .14 . 12 pen fleabane reached a comparable stage approxi- Letterman needlegrass . 18 .14 .09 Slender wheatgrass .20 .28 .11 mately 2 weeks later. Bromegrass .24 .36 .13 The three forbs were nutritionally superior to Elk sedge . 18 Aspen fleabane .4O .31 .21 .24 the grasses through the first half of the grazing pe- Agoseris .38 .36 .34 riod. Aspen peavine averaged highest in crude pro- Aspen peavine .23 .22 .18 tein, and agoseris was highest in phosphorus and CALCIUM: calcium. Idaho fescue .56 .62 .55 Thurber fescue .36 39 .31 It is interesting that the forbs, even after they Letterman needlegrass . 56 : 52 .46 were dry and decumbent, showed crude protein, Slender wheatgrass .44 .45 .47 Bromegrass . 58 .54 .57 phosphorus, and calcium levels still above the min- Elk sedge .58 Aspen fleabane 1.46 1.31 1.74 1.74 imum nutrient requirements prescribed for main- Agoseris 1.94 2.04 2.84 taining normal growth of 600-lb steers or heifers Aspen peavine 1.66 1. 78 2.29 (National Research Council, 1963). In contrast, by late August when the grass seeds were being disseminated, crude protein and phosphorus were grazed, but it rated 2.5 times higher than any other below the prescribed minimum requirement in the species. Kentucky bluegrass, subalpine needlegrass, three major forage grasses. By mid-September those (Elymus glaucus and blue wildrye Buckl.) were elements were deficient in the herbage of all used in excess of 10% but produced relatively little grasses. forage in the aspen. Calcium was ample in each of the species through- Forty-nine species of forbs were encountered in out the entire grazing season. The calcium content the aspen type, and 34 of these were noticeably of the three forbs averaged almost four times higher utilized. Use was highest on false sunflower, which than the grasses, and tended to increase in the later was grazed only 7% less than in the grassland; how- developmental stages in contrast to the grasses. ever, meadowrue ranked highest in relative forage Elk sedge samples from the aspen type were ob- value of the forbs. Other forbs utilized at least 5% tained at three periods during the 2 years. Since were: flowering had been completed, only the leaves were Days after grazing began collected for analysis. The crude protein content 21 38 (Continued) of elk sedge through late August was slightly higher Aspen fleabane rucemosa (L.) Desf.) than that of Idaho and Thurber fescues. By mid- Dandelion Goldenrod (Solidago ciliosu September the protein content of the three species Rydberg penstemon (Penste- Greene) was similar. Similarly, phosphorus content of elk mon rydbergii A. Nels.) Agoseris sedge at this late date was about minimal for the Agoseris Lewis flax (Linum Zewisii nutritional requirements of the animals, but cal- Grays pedicularis (Pedicularis Pursh) gruyi A. Nels.) Dandelion cium was adequate. Orange sneezeweed (Hele- Most grass and sedge herbage on Black Mesa ap- nium hoopesii A. Gray) 57 pears to be nutritionally deficient after late Au- Pseudocymopterus (Pseudo- gust. Animal weights early in the study showed an 38 cymopterus montunus (A. average of 1.5 lb/head/day gain from approxi- Aspen fleabane Gray) Coult. & Rose) mately September 1 until October 1. The gain Solomonplume (Smilacina Grays pedicularis from mid-July until September 1 averaged 2.4 lb/ Forage Nutritive Value.-Chemical analyses of head/day, or about 62% more than late in the sea- forage collected at specific phenological stages dur- son. When grazing is terminated it is doubtful MOUNTAIN GRASSLAND-ASPEN RANGES 107

whether any weight gains are being made. Studies maintain an adequate level until they dry and are in other areas have shown significant losses in ani- no longer grazed. Calcium levels of forbs and mal weights late in the season (Klipple and Cos- grasses were adequate throughout the grazing sea- tello, 1960; Johnson, 1953). son. LITERATURE CITED Summary ASSOCIATION OF OFFICIAL AGRICUI~TURAL CHEMISTS. 1960. Mountain grassland and associated aspen ranges Official Methods of Analysis. Ed. 9. Washington, D. C. furnish forage for a large segment of the livestock 832 p. industry of western Colorado. To characterize these COSTELLO, DAVID F. 1944. Important species of the major forage types in Colorado and Wyoming. Ecol. Monogr. ranges, data are presented which illustrate herbage 14: 107-134. production, cattle preference, and nutritional value COSTELLO, DAVID F. 1954. Vegetation zones in Colorado. of the major forage species. In H. D. Harrington. Manual of the Plants of Colorado. The study site is on Black Mesa about 30 miles Sage Books, Denver. 666 p. west of Gunnison, Colorado, at an elevation of ap- HURD, RICHARD M. 1961. Grassland vegetation in the proximately 9,500 ft. Hereford steers or heifers Big Horn Mountains, Wyoming. Ecology 42:459-467. have grazed the experimental area from mid-July HURD, RICHARD M., AND FLOYD W. POND. 1958. Relative until approximately October 1 since 1954. preference and productivity of species on summer cattle Herbage production on the grassland averaged ranges, Big Horn Mountains, Wyoming. J. Range about 1,500 lb/acre air dry, and reached its peak Manage. 11: 109-I 14. JOHNSON, W. M. 1953. Effect of grazing intensity upon between mid-July and early August, depending vegetation and cattle gains on ponderosa pine-bunchgrass upon the weather. Composition of the herbage ranges of the Front Range of Colorado. U. S. Dep. Agr. averaged 44y0 grasses and grass-like species, 5 1% Cir. 929. 36 p. forbs, and 5% shrubs. KEARNEY, THOMAS H., AND ROBERT H. PEEBLES. 1942. The associated aspen ranges, which are contigu- Flowering Plants and Ferns of Arizona. U. S. Gov. ous with the grasslands, yield approximately half Printing Office, Washington D. C. 1069 p. as much herbage. Forbs comprise a higher per- KLIPPLE, G. E., AND DAVID F. COSTELLO. 1960. Vegeta- centage of the herbage than in the grassland. tion and cattle responses to different intensities of grazing Towards the end of August, the forbs on both types on short-grass ranges on the central Great Plains. U.S. Dep. Agr. Tech. Bull. 1216. 82 p. of range become dry and thereafter contribute very LANGENHEIM, JEAN L. 1962. Vegetation and environmental little to the animals’ diet. patterns in the Crested Butte area, Gunnison County, Idaho fescue is the primary herbage producer in Colorado. Ecol. Monogr. 32: 249-285. the grassland, while elk sedge is the major producer NATIONAL RESEARCH COUNCIL. 1963. Nutrient Require- in the aspen type. Other grasses which furnish ap- ments of Beef Cattle IV. Publication 1137. Revised preciable amounts of grassland herbage include Washington, D. C. 30 p. Thurber fescue and Letterman needlegrass. Fre- PECHANEC, J. F., AND G. D. PICKFORD. 1937a. A weight mont geranium contributes more herbage than any estimate method for the determination of range or pasture other forb in the grassland, but production in the production. J. Amer. Sot. Agron. 29:894-904. aspen is furnished by a variety of forbs. PECHANEC, J. F., AND G. D. PICKFORD. 193713. A compari- son of some methods used in determining percentage On the grassland ranges, cattle preference, as de- utilization of range grasses. J. Agr. Res. 54:753-765. termined by periodic estimates of utilization, was PICKFORD, G. D., AND ELBERT H. REID. 1942. Basis for highest for Kentucky bluegrass and false sunflower. judging subalpine grassland ranges of Oregon and Wash- The latter species is also most preferred on the as- ington. U.S. Dept. Agr. Cir. 655. 38 p. pen ranges. REID, ELBERT H., JACOB L. KOVNER, AND S. CLARK MARTIN. The product of herbage production and utiliza- 1963. A proposed method of determining cattle num- tion provided an index of forage value. On the bers in range experiments. J. Range Manage. 16:184-187. grassland, Idaho fescue ranked more than twice as STRICKLER, GERALD S. 1961. Vegetation and soil condition high as any other species, followed by Letterman changes on a subalpine grassland in eastern Oregon. needlegrass and Thurber fescue. Aspen fleabane, Pacific Northwest Forest and Range Experiment Station, U.S. Forest Service, Res. Paper 40. 46 p. aspen peavine, and agoseris are the major forage TURNER, GEORGE T., AND EDWARD J. DORTIGNAC. 1954. In- species of forbs. Elk sedge and meadowrue ranked filtration, erosion and herbage production of some highest in forage value in the aspen type. mountain grasslands in western Colorado. J. Forest. Chemical analyses indicated the forage grasses 52:858-860. may be deficient in crude protein and phosphorus U.S. FOREST SERVICE. 1937. Range Plant Handbook. U.S. after seed ripening. Forbs, on the other hand, Gov. Printing Office, Washington, D.C. n.p.