• Viewpoint: The state and transition model applied to the herbaceous layer of Argentina's calden forest

      Llorens, E. M. (Society for Range Management, 1995-09-01)
      The ecological trends in the vegetation of the caldén (Prosopis caldenia Burk.) forest of central Argentina have generally been explained with a model that assumed a unique equilibrium state or "climax." This model does not adequately explain the ecological changes that occur in the understory of the caldén forest. Recently, models that present different stable states of vegetation have been suggested. These vegetation states do not change unless relatively drastic management or climatic actions occur. Observations of vegetation changes, grazing regimes, and other aspects of management permitted the development of a basic scheme to explain changes in the herbaceous layer in the caldén forest, based on the state and transition model. Five stable states and 9 transitions are proposed to account for current herbaceous associations and their origins. This model seems to more accurately explain transitions between the different vegetation states in the area, some of which could not be readily explained by the "climax" model.
    • Viewpoint: Trend assessment by similarity—a demonstration

      Ratliff, R. D. (Society for Range Management, 1993-03-01)
      Methodology for assessing trend in range condition is still evolving. This paper demonstrates use of Dice's community similarity coefficient, 2a/(2a + b + c), with communities present at 3 times and a notional community as a goal. Coefficients range from 0 (indicating a complete lack of similarity) to 1 (indicating complete similarity). Similarity is classed as low (0 - 0.25), moderate (0.26 - 0.50), high (0.51 - 0.75), or full (0.76 - 1). Study of time-goal coefficent graphs is suggested for deciding whether trend is up, down, or static. Defining goals and lack of statistical tests are major limitations. The goal concept and use of data standardization are discussed.
    • Viewpoint: Ungulate herbivory, willows, and political ecology in Yellowstone

      Kay, C. E. (Society for Range Management, 1997-03-01)
      Contentions that willows (Salix spp.) on Yellowstone National Park's northern range have declined because of climatic change, fire suppression, reduced chemical defenses, or other natural factors are not supported by available data. Instead, willows have declined due to repeated browsing by an unnaturally large elk population. By established standards Yellowstone contains some of the worst overgrazed willow communities in the entire West, but that was not true in earlier times. Prior to park establishment, predation by Native Americans kept elk and other ungulate numbers low which, in turn, prevented herbivores from impacting Yellowstone's plant communities, as those animals do today. Finally, the condition of willows in the park is also a test of Yellowstone's "natural regulation" program, and that paradigm must also be rejected.
    • Viewpoint: Western juniper expansion: Is it a threat to arid northwestern ecosystems?

      Belsky, A. J. (Society for Range Management, 1996-01-01)
      Many ranchers, rangeland managers, and range scientists in the Pacific Northwest consider western juniper (Juniperus occidentalis Hook.) to be an invading weed that reduces water infiltration, dries up springs and streams, increases erosion, reduces biodiversity, and reduces the quality and quantity of forage for livestock and wildlife species. Although there is little scientific evidence supporting most of these beliefs, they are currently being used as rationales for controlling juniper on public and private lands. Similar views were held about pinyon-juniper woodlands in the Southwest and Great Basin from the 1940's through the 1960's, when efforts were also made to control woodland expansion. Pressures to control the further spread of western juniper and reduce its density in woodlands are increasing. Because of the paucity of information on the environmental effects of western juniper expansion in the Northwest, this paper primarily reviews evidence from earlier studies of pinyon-juniper woodlands in the Southwest and Great Basin. These studies rejected similar assumptions about the deleterious effects of pinyon-juniper expansion on ecosystem properties and call into question current rationales for controlling western juniper in the Northwest. These studies also suggest that while the expansion of juniper might alter species composition and decrease herbaceous biomass in grasslands and shrublands, they have few detrimental effects on streamflow, aquatic organisms, soil properties, or wildlife habitat.
    • Viewpoint: Who are those Smiths?

      Beetle, Alan A. (Society for Range Management, 1988-09-01)
    • Viewpoint: Zootic Climax

      Houston, Douglas B.; Cole, Glen F. (Society for Range Management, 1974-05-01)
    • Viewpoints: Observations on Why Mongrels May Make Effective Livestock Protecting Dogs

      Coppinger, R. P.; Smith, C. K.; Miller, L. (Society for Range Management, 1985-11-01)
    • Viewpoints: Range condition from an ecological perspective: Modifications to recognize multiple use objectives

      Pieper, R. D.; Beck, R. F. (Society for Range Management, 1990-11-01)
      Two changes in traditional range condition analyses are recom- mended: (1) to replace the terms excellent, good, fair, and poor with ecological equivalents of climax, late seral, mid-seral, and early seral in cases where this is practical; and (2) to develop relationships between products (e.g., livestock, wood products, water) or conditions (e.g., infiltration, site stability, erosion) and successional stage or state. Such information will allow the land manager to evaluate possible tradeoffs between managing for a particular successional stage or state and particular goods or services.
    • Vigilance in Cattle: The Influence of Predation, Social Interactions, and Environmental Factors

      Kluever, Bryan M.; Breck, Stewart W.; Howery, Larry D.; Krausman, Paul R.; Bergman, David L. (Society for Range Management, 2008-05-01)
      Vigilant behavior in wild ungulates is critical to guard against predation. However, few studies have examined vigilant behavior in domesticated ungulates. Considering the expansion of large predator populations, understanding vigilant behavior and factors that influence it will help with the management of livestock. We observed adult female cattle (Bos taurus L.) in open-range conditions where large predators (wolves [Canis lupus L.] and mountain lions [Puma concolor (L.).]) were common threats during summers of 2005 and 2006 in eastern Arizona. This study was designed to determine 1) to what extent cattle exhibit vigilant behavior compared to published data on wild ungulates, 2) whether predation events influence vigilance rates of cattle, and 3) whether social and environmental factors affect vigilance of cattle. Cattle exhibited vigilant behavior (3% +/- 0.19%) during peak foraging periods, but at a lower rate than wild ungulates. Cows with calves were more than twice as vigilant (4.5% +/- 0.46%) as those without calves (2.0% +/- 0.27%). Single cattle and groups of two to five exhibited higher vigilance rates (4.2% +/- 0.79%) than groups of six to 20 (2.5% +/- 0.32%) and groups of > 20 (3.0% +/- 0.41%). Cattle in groups of > 20 increased vigilance as visual obstruction increased. Mother cows whose calves were preyed upon (n = 5) exhibited a 3% to 48% increase in vigilance within 3 d after their calves were killed; this rate returned to near baseline levels after 10 d. Conversely, mother cows reduced foraging after their calves were killed from 88.5% +/- 1.69% to 43.5% +/- 11.4%; foraging rate also returned to near baseline levels after 10 d. Cattle exhibit vigilance at lower levels compared to wild ungulates, but this behavior appears to be at least partially an antipredatory behavior. Our findings provide support that predators can influence cattle behavior. 
    • Vigor of Idaho Fescue Grazed under Rest-Rotation and Continuous Grazing

      Ratliff, R. D.; Reppert, J. N. (Society for Range Management, 1974-11-01)
      The vigor of Idaho fescue in northeastern California was compared on plots grazed by two different approaches: one full 5-year cycle of rest-rotation grazing, at Harvey Valley; and repeated continuous grazing, at Grays Valley. Vegetative shoot lengths and numbers of flower stalks served as indicators of vigor. Vigor was higher on the Harvey Valley plots. The full-use treatments of rest-rotation grazing did not measurably reduce vigor, nor did the rest treatments improve it. Production of flower stalks appeared to depend on adequate spring precipitation and was not synchronized with the seed production phase of rest-rotation grazing. Continuous grazing at moderate intensity did not reduce plant vigor during the 5-year study period on the Grays Valley plot. The results suggest that moderate, continuous grazing permits Idaho fescue to maintain its vigor. But because rest-rotation grazing disrupts an apparent relationship between grazing use and precipitation, it may hold Idaho fescue vigor at a higher level than can continuous grazing.
    • Vigor of Idaho Fescue in Relation to Different Grazing Intensities

      Pond, F. W. (Society for Range Management, 1960-01-01)
    • Vigor of needleandthread and blue grama after short duration grazing

      Reece, P. E.; Bode, R. P.; Waller, S. S. (Society for Range Management, 1988-07-01)
      Grazing treatments were applied to pastures in western Nebraska from 1980 through 1983 to examine the influence of short duration grazing (SDG) on plant vigor. The 3 treatments were: (1) 4 years of SDG, (2) 3 years of SDG followed by 1 year of rest, and (3) 4 years of rest. Total nonstructural carbohydrate (TNC) concentrations of stem bases, mean tiller weight, and tiller number/plant of etiolated growth, and paired differences in spring growth between covered and uncovered plants were used to evaluate vigor of needleandthread (Stipa comata Trin. & Rupr.) and blue grama [Bouteloua gracilis (HBK) Lag. ex Griffiths]. Two 7-pasture, 1-herd SDG systems were used. Length of use and deferment periods, stocking density, stocking rate, and sequence of pasture use were constant throughout the study. Grazing treatments reduced the vigor of both study species, but the vigor of blue grama was more sensitive to treatments than needleandthread. Levels of TNC in needleandthread were not affected by grazing treatments. Concentrations of TNC in blue grama recovered to levels of ungrazed plants after 1 year of rest in some but not all pastures. Grazing increased the number of tillers/plant, but reduced total organic reserves of both species as measured by etiolated growth. Assimilates produced in early spring growth appeared to be more important for tiller initiation in plants that had been grazed than in ungrazed plants.
    • Visitor perceptions about cattle grazing on National Forest land

      Mitchell, J. E.; Wallace, G. N.; Wells, M. D. (Society for Range Management, 1996-01-01)
      Visitors to the Big Cimarron Watershed in the Uncompahgre National Forest, Colorado, had varying attitudes about cattle grazing. Without cuing, 9% of all visitors listed livestock as a source of interference. Local and rural Colorado residents tended to be more agreeable to livestock presence than other visitors in 1992; however, significant differences could not be detected the following year. No relationship existed between the prevalence of a perceived grazing-recreation conflict and visitors' home community size, nor the size of the community where they grew up. Visitors in dispersed campsites tended to be more critical of grazing than those in developed campgrounds. When given a choice, the number of visitors indicating that range livestock added to their stay (34%) was no different than the number stating a negative relationship (33%). Understanding visitor characteristics during range allotment planning may help lessen conflicts between livestock grazing and recreational usage by aiding in plan development and the design of effective interpretive programs.
    • Vitamin A and B-carotene in Liver and Blood of Cows Grazing Pangolagrass

      Kirk, W. G.; Shirley, R. L.; Easley, J. F.; Peacock, F. M. (Society for Range Management, 1970-03-01)
      Mature grade Brahman cows grazing pangolagrass (Digitaria decumbens Stent.) from 3 to 17 years as the only source of nutrients other than common salt and red salt had an average of 2624 mcg vitamin A and 59 mcg B-carotene per gram dry liver and 46 mcg vitamin A and 1020 mcg B-carotene per 100 ml blood plasma. The liver of a 1168 pound cow had the equivalent of 16.3 million I. U. vitamin A. The cows had livers with approximately 28 times more vitamin A, and plasma 5.5 times more B-carotene than steers fed a finishing ration containing 10% yellow corn meal and 5% alfalfa meal for 140 days. Beef cows grazing well managed Florida improved pasture would obtain more than sufficient vitamin A for maintenance, reproduction, and milk production as indicated by their performance and storage of this vitamin.
    • Vivipary, Proliferation, and Phyllody in Grasses

      Beetle, A. A. (Society for Range Management, 1980-07-01)
      Some temperate grasses have the ability to produce in their inflorescence modified spikelet structures that act to reproduce the species vegetatively. These types may be either genetically fixed or an occasional expression of environmental change.
    • Vizcacha’s Influence on Vegetation and Soil in a Wetland of Argentina

      Arias, Santiago M.; Quintana, Rubén D.; Cagnoni, Marcela (Society for Range Management, 2005-01-01)
      We examined the influence of the plains vizcacha (Lagostomus maximus) on the vegetation structure and the characteristics of soil in a wet grassland area of Argentina. This rodent lives in social groups that share a communal burrow system that is occupied for several generations. The areas in which the vizcacha live and feed are strongly affected by grazing, trampling, and soil removal, exhibiting extensive biopedturbation. To evaluate these effects, we carried out a vegetation survey, along areas extending outward from active vizcacheras, analyzing abundance, plant diversity, vegetation cover, and biomass. We also established soil properties, analyzing physical and chemical variables from the center of the colonies to the grassland matrix. Our results show that vizcachas have indeed affected vegetation, diminishing plant cover and grass biomass in their grazing areas. Vegetation in both areas without animal activity and those of intense grazing was dominated by a few characteristic species. We verified the hypothesis of greatest diversity in areas of moderate disturbance. Perturbed areas had higher cation exchange capacity and electric conductivity and higher clay and sodium contents than the other areas. The rodents’ activity introduces a recurrent disturbance factor to the landscape of this region, the outcome of which is the alteration of both the composition and structure of the botanical communities, and some soil properties, scaled in gradients of decreasing effect from the center of a colony to the periphery.  
    • Volatile oil contents of ashe and redberry juniper and its relationship to preference by Angora and Spanish goats

      Riddle, R. R.; Taylor, C. A.; Kothmann, M. M.; Huston, J. E. (Society for Range Management, 1996-01-01)
      Angora and Spanish goats (Capra bircus) were exposed to ashe (Juniperus ashei Buchholz) female, ashe male, redberry (Juniperus pinchotti Sudw.) female and redberry male branches in cafeteria style feeding trials. Preferences were consistent across seasons (except winter). Spanish goats generally consumed more juniper than Angoras. Both breeds preferred ashe over redberry juniper and female over male plants. Concentrations of volatile oils varied significantly between species of juniper and among seasons, but not between sexes. Concentrations of total oils were greater in the spring and summer than in the fall and winter. Concentrations of sabinine+beta-pinene were greater in redberry than ashe for all seasons. Concentrations of myrcene were significantly greater for redberry during the spring and summer. Significant correlation of oil concentration with grams of juniper consumed indicated that specific oils were influencing preference for juniper. Correlations were similar for Angora and Spanish goats, indicating no differences between goat breeds in sensitivity to oils.
    • Volcano Ranching: Problems and Opportunities in Management of Hawaiian Range Land

      Britten, E. J. (Society for Range Management, 1959-11-01)
    • Voles Can Improve Sagebrush Rangelands

      Frischknecht, N. C.; Baker, M. F. (Society for Range Management, 1972-11-01)
      During cyclic population peaks, voles kill and damage sagebrush and other shrub species over large areas. Damage is greatest when a dense, ungrazed herbaceous understory exists and when the snowpack persists throughout the winter. If peaks in population could be predicted, grazing should be managed to leave all possible herbaceous cover on areas where killing of brush is desired; conversely, grazing by cattle should be heavy where perpetuation of shrubs is preferred.
    • Voles Damage Big Sagebrush in Southwestern Montana

      Mueggler, W. F. (Society for Range Management, 1967-03-01)
      Extensive destruction of big sagebrush in southwestern Montana in the winter of 1963-64 is attributed to a sudden irruption of the population of voles. Such extensive sudden destruction of browse species over wide areas concerns both ranchers and game managers because it can affect production of browse and forage for several succeeding years.