The transition of range utilization from a qualitative concept in the early years of range management to a quantitative concept in today's range management science has been problematic. This paper (1) evaluates the origins, confoundings, and interpretations of range utilization in range management science, (2) presents an explicit allocation array of variables to replace the range utilization concept, and (3) examines the role of range utilization specifically, and management science generally in the present and future message of the Society for Range Management, and in range management science.

The effects of stocking rate and grazing method on performance of yearling beef cattle grazing tallgrass prairies in north-central Oklahoma were evaluated from 1989 to 1994. Pastures dominated by big bluestem [Andropogon gerardii Vitman], little bluestem [Schizachyrium scoparium (Michx.) Nash], and indiangrass [Sorghastrum nutans (L.) Nash], were allocated to either short duration rotational or continuous stocking methods and stocking rates ranging from 52 animal-unit-days (AUD) ha(-1) to 90 AUD ha(-1). Steers grazed the units from late April to late September. Precipitation was above average during the study period. Live weight gain per head was higher under continuous stocking than rotational stocking at all stocking rates. At 52 AUD ha(-1), individual gains under rotational stocking were 11% less than under continuous stocking. At 90 AUD ha(-1), individual gains under rotational stocking were decreased by 20%. Measurements of steer diets and forage standing crop suggest the reduction in weight gain was due to reduced forage intake under rotational stocking. Live weight gain per hectare increased with stocking rate and was higher with continuous stocking at all stocking rates. Net returns per hectare increased as stocking rate increased for both stocking methods but were lower for rotational stocking at all stocking rates. Variable costs per head would have to decrease by 24 to 34% under rotational stocking to equalize net returns between the 2 grazing methods. Unless the decline in gain per head can be reduced or eliminated, there is no economic incentive to implement rotational stocking under the conditions of this study.

Because of its high palatability and sustained levels of forage quality, antelope bitterbrush (Purshia tridentata Pursh DC) is one of the most desired shrubs on western U.S. rangelands. Bitterbrush has decreased in abundance in many areas, and efforts to foster its restoration have met with limited success. Because little information is available regarding the grazing management of newly established stands of bitterbrush, this study was undertaken to: 1) determine the effects of early and late-season cattle grazing on bitterbrush, 2) determine when cattle were most likely to forage on these shrubs, and 3) relate use of shrubs to the quantity, quality, and phenology of accompanying herbaceous forages. Ungrazed (control), early-grazed, and dormant-grazed paddocks supporting 3+ year old bitterbrush (randomized complete block design, N = 3) were monitored for 3 years to accomplish this task. When grasses were green and growing, cattle grazed about 6% of the shrubs per day. When grasses and forbs were dormant, about 13% of the shrubs were grazed each day. Rates of use of shrubs were not significantly (P > 0.05) correlated with amounts of accompanying herbage available (r(2) = 0.40), levels of forage utilization (r(2) = 0.00), stocking pressure (r(2) = 0.00), crude protein (r(2) = 0.02) or neutral detergent fiber content (r(2) = 0.59) of accompanying forages, or digestibility of the forages as measured by in-vitro organic matter disappearance (IVOMD) (r(2) = 0.62). In step-wise regression analyses Julian date alone accounted for 92% of the variation in rates of use of shrubs and the addition of IVOMD accounted for 98% of the variation. This suggested that bitterbrush was grazed more heavily as the growing season advanced and forage quality of the grasses declined. Shrub height, diameter, and volume were reduced by early grazing in 1 of 3 years when turn out was delayed until grasses were entering anthesis. Cattle grazing when grasses were dormant caused reductions in height, diameter, and volume of the shrubs in all 3 years. Rates of shrub mortality were unaffected by treatment. Bitterbrush in all treatments experienced significant reductions in height, diameter, and volume from wildlife use during the winters of 1993 and 1994 but not 1995. When trials were terminated, shrubs in early-grazed paddocks exceeded (P < 0.10) their counterparts in the dormant grazed paddocks in height, diameter, and volume.

Idaho fescue (Festuca idahoensis Elmer), a palatable native perennial bunchgrass, has persisted on degraded sagebrush-steppe despite invasion by alien plants, excessive livestock grazing, and increased density of woody vegetation due to fire suppression. Survival of these populations in the presence of competitive alien plants suggested 2 possibilities: 1) that Idaho fescue produces seedlings that successfully compete for soil resources with alien invaders, and 2) that Idaho fescue seedlings tolerate stress caused by resource uptake by alien neighbors. We compared germination and growth of Idaho fescue from an undisturbed population with that of conspecific populations from disturbed (grazed and invaded) sites to determine whether disturbed-site seedlings had greater potential for resource capture. Recruitment in Idaho fescue from degraded sites did not appear to be aided by rapid seed germination or greater tolerance of moisture stress during germination. A greater proportion of seeds from the undisturbed site germinated; they germinated faster, and were no more sensitive to water stress, than were seeds from disturbed sites. For both groups, decreasing water potential from 0 to -0.5 MPa had little effect on germination percentages but declined at -1 Mpa. Germination rates slowed with decreasing water potential. Though Idaho fescue from undisturbed and disturbed sites extended roots down the soil profile with equal speed, seedlings from the undisturbed site produced 3.5 times more root length, had 2.7 times greater root length density, and 3.4 times more leaf area than disturbed-site Idaho fescue. The higher growth rate and greater root length density in Idaho fescue from the undisturbed site translates to greater exploration and exploitation of the environment. The 2 Idaho fescue groups had equivalent specific root length, specific leaf area, and root weight ratio. Idaho fescue from disturbed sites showed strong, positive geotropic growth whereas branching and diageotropic growth were greater in Idaho fescue from the undisturbed site. Cheatgrass (Bromus tectorum L.) extended roots faster than did Idaho fescue, with 17 times the root length, 6 times the root length density, and 10.8 times the leaf area of undisturbed-site Idaho fescue. Cheatgrass and Idaho fescue had equivalent specific leaf area, but specific root length of Idaho fescue was nearly twice that of the alien. Roots accounted for about 31% and 55% of cheatgrass biomass. Competitive ability did not appear to promote recruitment in Idaho fescue populations on degraded rangelands. Idaho fescue seedlings from the undisturbed-site were better competitors than disturbed-site seedlings, but interference from neighboring cheatgrass most strongly inhibited shoot growth of both Idaho fescue and cheatgrass. Idaho fescue had little effect on cheatgrass shoot growth. Selection of stress-tolerant genotypes from original populations may best explain the continued existence of Idaho fescue on grazed and invaded sites. We suggest that tolerance of moisture stress combined with vegetative longevity, are mechanisms behind Idaho fescue's persistence.

Nutritive quality of vegetation is important when evaluating the habitat to sustain wildlife. Crude protein, fiber content and in vitro digestibility were evaluated for 17 shrubs, 7 trees, 2 ferns, 3 forbs, and 4 grasses species of Galician (NW Spain) woodlands understory. Nutritional attributes showed forbs, Frangula alnus Miller, Hedera helix L. and Linocera periclymenum L. as plants with the highest forage value. Crude protein levels of Rubus sp., Robinia pseudacacia L., Castanea sativa Miller, and grasses could meet deer nitrogen requirements but their low IVOMD and high fiber percentages make them mid-low feed value forages. Understory layer of oakwoods provides higher quality forage than conifer or eucalyptus stands. Crude protein and digestibility of plants peaked in spring-summer and the highest fiber content occurred in winter. Seasonal fluctuations in forage quality makes seasonal management and seasonal plans necessary.

Angora mutton goats (Capra hircus) were fed diets of either live oak [Quercus virginiana (Small) Sarg. var. fusiformis], alfalfa hay (Medicago sativa L.), Coastal bermudagrass hay (Cynodon dactylon (L.)Pers.) or female ashe juniper (Juniperus ashei Buchholz) plus Coastal bermudagrass hay during the spring and fall of 1991 in a digestion/metabolism study. Nitrogen concentration of Coastal bermudagrass hay was nearly equal to that of alfalfa hay; nitrogen concentration of ashe juniper and live oak were much lower than those of the hays, and were higher in fall than spring. Dry matter intake and dietary nitrogen were highest for alfalfa hay, intermediate for Coastal bermudagrass hay, and lower for ashe juniper and live oak. Goats retained more nitrogen when consuming alfalfa and Coastal bermudagrass hays than juniper or live oak during fall, but differences were smaller (P > 0.10) during spring. Nitrogen balance was negative for goats consuming live oak in the spring. Nitrogen balance was positive for live oak in the fall and positive for ashe juniper for the spring and fall. Animals fed hay diets had higher levels of urine output than those fed juniper or live oak. Dry matter digestibility of juniper and live oak diets was less in fall than in spring. During fall, dry matter intakes of juniper and live oak were significantly lower than those of alfalfa and Coastal bermudagrass hays. We conclude that both ashe juniper and live oak foliage can provide nutrients for goats but only as portions of diets.

Lifetime productivity of fescue grasslands (Festuca scabrella var. campestris Rydb.) is enhanced by fall and winter grazing as opposed to summer grazing. However, forage quality is below the maintenance requirements of cattle and weathering losses will reduce available forage. Cows tend to lose weight and backfat prior to calving if their only feed source through fall and winter is native grassland. Maintaining adequate cow condition for spring calving is important to prevent long term losses associated with reduced calf birth weights, lower cow fertility and reduced cow longevity. Cow condition can be improved by having cows graze annual forage in the fall or by supplementing the cows with grain screenings. Alternatively, cows can be fed in a feedlot prior to calving to restore body condition lost in grazing native grassland in the fall and winter. Results from a 3-year experiment showed that winter wheat pasture grazed in the fall, supplemented with grain screenings was generally the least expensive alternative (ranging from 70 cow(-1) at low barley prices approaching .051 kg(-1), to 97 cow(-1) at high barley prices approaching 0.175 kg(-1)) for maintaining cow condition prior to calving. Restoring cow condition in a feedlot prior to calving was less expensive that provision of fall annual pasture when grain prices were low (barley price below 0.14 kg(-1).