• Factors Influencing Development of Cryptogamic Soil Crusts in Utah Deserts

      Anderson, D. C.; Harper, K. T.; Holmgren, R. C. (Society for Range Management, 1982-03-01)
      The relation of some physical and chemical soil characteristics to cryptogamic crust development was determined from sites in semidesert regions of southern Utah. The effects of grazing on cryptogamic crust development also was examined. Electrical conductivity, percentage silt, and soil phosphorus were found to be correlated with well-developed cryptogamic crusts. Both total cryptogamic cover and the number of cryptogamic species decreased under grazing pressure. The management of rangelands, especially in arid regions, would be strengthened by understanding the role of cryptogamic crusts and considering them in range management decisions.
    • Factors influencing eastern redcedar seedling survival on rangeland

      Schmidt, T. L.; Stubbendieck, J. (Society for Range Management, 1993-09-01)
      Eastern redcedar (Juniperus virginiana L.) is the most rapidly expanding woody species on rangeland in the Great Plains. Reasons for the expansion and management solutions have not been determined. The objective of this study was to determine the effect of year of establishment, grazing impacts, and aspect on the survival of eastern redcedar seedlings. Subplots of 10 transplanted eastern redcedar seedlings were replicated at 2 sites in west-central Nebraska. Plots were established in 1987 and 1988 under 3 different grazing levels: actively grazed, actively grazed until 1987 and then fenced from grazing, and not grazed for greater than or equal to 50 years. Split-plots within the 3 grazing levels were established on 3 different aspects: north-facing, south-facing, and flat. Seedling survival was evaluated 6,18, and 30 months after establishment period. The year that the seedling was established influenced seedling survival after 18 months. Grazing effects and aspect were significant factors in the survival of eastern redcedar seedlings for all 3 evaluation periods. Highest survival for grazing effects occurred where eastern redcedar seedlings were transplanted into plots that were grazed until 1987 and then fenced (57% +/- 1.5%). Lowest survival rates concerning grazing were for areas that were not grazed for greater than of equal to 50 years (40% +/- 3.0%). North-facing slopes had the highest survival after 30 months (65% +/- 2.4%). South facing slopes had the lowest survival after 30 months (34% +/- 2.9%). Land managers may be able to reduce eastern redcedar seedling establishment on grazed range lands through different grazing practices.
    • Factors Influencing Germination in Beardless Wildrye

      Wagner, R. C.; Chapman, S. R. (Society for Range Management, 1970-11-01)
      The effects of pretreatment, strains, temperature and germination solutions on germination were studied in beardless wildrye. Rate of imbibition was also studied. Total imbibition was not influenced by either strains or solutions. For the two strains studied optimum conditions appear to be germination in distilled water with alternating temperatures of 15-20 C preceded by moist prechilling at 1.5 C.
    • Factors Influencing Halogeton Invasion of Crested Wheatgrass Range

      Frischknecht, N. C. (Society for Range Management, 1968-01-01)
      Halogeton first infested the Benmore Experimental Area on heavily grazed "slick spots," where soils contain more total soluble salts and greater amounts of exchangeable sodium than adjacent areas. Subsequently, halogeton profusely invaded units heavily grazed (80% utilization) in spring as well as other heavily grazed slick spots in lightly grazed (50%) and moderately grazed (65%) units. Heavy precipitation in the preceding July-September period and in May-June of the current year increases both abundance and vigor of halogeton. Occasional deferment from spring grazing or rest-rotation grazing is required to prevent invasion or to reduce abundance of halogeton, especially in slick-spot areas.
    • Factors Influencing Herbage Weight Of Idaho Fescue Plants

      Hurd, R. M. (Society for Range Management, 1959-03-01)
    • Factors influencing infiltrability of semiarid mountain slopes

      Wilcox, B. P.; Wood, M. K.; Tromble, J. M. (Society for Range Management, 1988-05-01)
      The objective of this research was to determine the effects of selected vegetation, soil, rock, and slope variables on infiltration of semiarid rangelands with slope gradients ranging from 0-70%. Analyses were made on 2 sets of data collected a year apart in the Guadalupe Mountains of New Mexico and consisted of Pearson and partial correlation analysis of the dependent infiltration variables and independent site variables. In addition, infiltration was regressed against uncorrelated factors produced by factor analysis. Vegetal cover and biomass strongly influenced infiltration. The relative importance of grasses, shrubs or litter was dependent on their respective abundance, especially grass. Soil depth also limited infiltration especially as soil water storage became satisfied. Infiltrability was negatively correlated with rock cover and the smallest rock size fragments were the most negatively related. When the effects of vegetal cover and slope were removed (using partial correlation analysis) however, the median sized rock fragments (26-150 mm) were positively related to infiltrability, and the smallest rock fragements (2-12 mm) were negatively related. Partial correlation analysis also suggested a positive correlation between infiltrability and slope gradient.
    • Factors Influencing Infiltration and Erosion on Chained Pinyon-Juniper Sites in Utah

      Williams, G.; Gifford, G. F.; Coltharp, G. B. (Society for Range Management, 1972-05-01)
      Relationships between vegetal and edaphic factors and infiltration rates and erosion as measured on 550 infiltrometer plots at chained pinyon-juniper sites in Utah were analyzed by multiple regression analysis. Those factors most important for predicting infiltration rates (regardless of time interval) included total porosity in the 0-3 inch layer of soil, percent bare soil surface, soil texture in the 0-3 inch layer of soil, and crown cover (percent or tons per acre). The ability to predict infiltration rates (as determined by R2) varied with time and geographic location. Not only did predictive ability vary, but independent variables explaining such variance also changed with time and location. Factors that influence sediment discharge were so variable from one geographic location to another that no consistent relation was found./El estudio se llevó a cabo en el Estado de Utah de E.U.A. con los objetivos de determinar que factores influyen más la erosión e infiltración de agua. Se usaron 550 infiltrometers a través de los años 1967 y 1968 y en varias localizaciones en ambos sitios de pino y enebro controlado por la cadena y sin control. Los resultados fueron analizados por regresión múltiple. Se encontraron que los factores que ocurrieron con más frecuencia en la ecuasión de predicción fueron la parosidad total en la copa de 0-3 pulgadas del suelo, porcentaje de suelo desnude, textura del suelo en la copa de 0-3 pulgadas y la cobertura vegetal. La habilidad para predicir la intensidad de la infiltración fué variable durante el año y entre las localizaciones los factores independientes que explican dicha variación fueron también variables durante el año y entre las localizaciones. Los factores que influyen erosión fueron muy variables enter las localizaciones y por éso no fué posible encontrar una interrelación consistente entre la intensidad de erosión y los factores de medio-ambiente.
    • Factors Influencing Intake of Mineral Supplements by Cattle on Southern Forest Range

      Duvall, V. L.; Whitaker, L. B. (Society for Range Management, 1970-09-01)
      Among cattle fed cottonseed cake daily in winter, salt and bonemeal consumption was greater on moderately grazed range (48% utilization) than on ranges grazed either lightly (32%) or heavily (57%). Cattle on heavily grazed range ate much less bonemeal than others. On ranges grazed moderately, cattle fed cake on alternate days in winter consumed the most salt from ad libitum supply and also ate the most bonemeal. Cattle self-fed a cottonseed meal-salt mixture ranked second in bonemeal consumption and lowest in voluntary intake of salt. Total salt eaten annually by these animals was much greater than for those fed protein supplement by other methods, however, and voluntary intake continued yearlong, even though the ration furnished far more salt than needed in winter./El estudio se llevó a cabo en el estado de Louisiana en un pastizal de Andropogon tener y Andropogon divergens, comprendiendo como potreros pastoreados con vacas todo el año, con tres cargas de pastoreo, pesada, moderada y ligera. Los animales que disponian de harinolina diariamente durante el invierno, consumieron más sal y harina de hueso en la carga moderada (40% de uso de forraje producido) en relación a las otras dos. En la carga pesada consumieron menos harina de hueso. También las que consumieron harinolina en forma terciada (un día si y otro día no) pero en la carga moderada, consumieron más sal y harina de hueso que las otras dos cargas. Las vacas suplementadas con una mezcla de harinolina y sal ad libitum, ocuparon el segundo lugar en el consumo de harina de hueso y el último en el de sal, sin embargo, la cantidad total de sal consumida por dichos animales, fue el más alto.
    • Factors influencing interrill erosion from semiarid slopes in New Mexico

      Wilcox, B. P.; Wood, M. K. (Society for Range Management, 1989-01-01)
      This rainfall simulation study evaluates the effects of slope, vegetation, rock, and soil characteristics on interrill erosion of semiarid slopes of the Guadalupe Mountains of New Mexico. A single-nozzle rainfall simulator applied rainfall on slope gradients ranging from 0-70%. Multicollinearity in the data was corrected for by using partial correlation analysis. Interrill erosion was most influenced by slope gradient; however, the effect of slope gradient was modified by other factors, particularly vegetation. Vegetation greatly lessened interrill erosion, especially during the initial stages of runoff. Shrubs decreased interrill erosion more than did either grasses, litter, or forbs. Sediment concentration was greater from erosion pavements than from well-vegetated plots. Increases in rock cover, however, without corresponding decreases in vegetal cover, afforded additional protection against interrill erosion. Soil texture and soil depth were the most influential soil factors, particularly on steep slopes.
    • Factors Influencing Magnesium in High Plains Forage

      Fairbourn, M. L.; Batchelder, A. R. (Society for Range Management, 1980-11-01)
      Greenhouse and field experiments were conducted at the High Plains Grasslands Research Station to determine what might cause tetany-prone forage. The soil was analyzed for ammonium acetate-extractable cations, cation exchange capacity, and alkaline earth carbonates; and the successive harvests of forage plants were analyzed for magnesium (Mg), calcium (Ca), potassium (K), and nitrogen (N). Forages used in the study included legumes: 'Lutana' Cicer milkvetch (Astragalus cicer L.), 'Remont' sainfoin (Onobrychis viciafolia Scop.), 'Dawson', 'Vernal', 'Team', and 'Fremont' alfalfas (Medicago sativa L.); and grasses: 'Latar' orchardgrass (Dactylis glomerata L.), 'Fawn' tall fescue (Festuca arundinacea Schreb), 'Regar' bromegrass Bromus biebersteinii Roem & Schult.), 'Manchar' smooth bromegrass (Bromus inermis Leyss), 'Garrison' creeping foxtail (Alopercurus pratensis L.), 'Luna' pubescent wheatgrass [Agropyron trichophorum (Link) Richt.], and 'Greenar' intermediate wheatgrass [Agropyron intermedium (Host) Beauv.]. Forage Mg level increased when average soil temperature increased from 16.6 to 22.7 degrees C. Fertilization with 1,134 kg of Mg as MgSO4/ha did not increase forage Mg level. Later orchardgrass and Fawn tall fescue consistently produced forage containing more than 0.20% Mg, whereas wheatgrass species produced forage with Mg levels as low as 0.11%. All legumes had Ca levels ranging from 1.0 to 2.5%. One field crop of Later orchardgrass produced forage with a high K accumulation (K/Ca + Mg ratio of 2.7). Predication of blood-serum Mg from forage nutrient content indicated values from 17 to 31 mg/l in lactating cows.
    • Factors Influencing Microhistological Analysis of Herbivore Diets

      Vavra, M.; Holechek, J. L. (Society for Range Management, 1980-09-01)
      A study simulating herbivore diets was conducted to compare actual and estimated diet constituents as influenced by sample preparation technique and in vitro digestion. Nine plant species, three each representing grass, forb, and shrub forage classes were hand composited into three mixtures so that one forage class dominated each mixture. Samples of each mixture were then allotted to eight treatments involving combinations of grinding through a micro-Wiley mill, soaking in sodium hydroxide and in vitro digestion. Samples were then analyzed for botanical composition using the microhistological technique. In vitro digestion had the greatest impact on the difference between estimated and actual means. In digested samples grasses were overestimated while shrubs and forbs were underestimated. The preferred treatment involved grinding in a micro-Wiley mill and the sodium hydroxide soak.
    • Factors Influencing Patterns of Cattle Grazing Behavior on Shortgrass Steepe

      Senft, R.; Rittenhouse, L. R.; Woodmansee, R. G. (Society for Range Management, 1985-01-01)
      Factors influencing distribution of free-roaming cattle were studied on shortgrass steppe in northeastern Colorado. Spatial units selected for grazing were plant communities (soil-plant associations) and a stock-watering area. Regression models of grazing patterns were derived for growing- and dormant-season grazing patterns. Seasonal-grazing distribution was correlated with proximity to water (1/distance) and site-quality indicators. Internal validation of seasonal-grazing models indicated a good fit of predicted to observed patterns. Because ad hoc regression models lack wide applicability, relationships between spatial preference and vegetation properties were investigated. Combined relative measures of forage quality and quantity were good predictors of community preference. Measures of relative biomass or frequencies of forage species were poor predictors of spatial preference. The high correlation between preference and properties of plants composing the bulk of the diet suggests an interaction between diet selection and selection of grazing areas. The highest correlation occurred between relative community preference and relative aboveground standing nitrogen (crude protein).
    • Factors influencing pine needle consumption by grazing cattle during winter

      Pfister, J. A.; Adams, D. C. (Society for Range Management, 1993-09-01)
      Ponderosa pine (Pinus ponderosa Lawson) needles cause abortions in pregnant cows. We examined pine needle consumption by cattle in 2 trials in eastern Montana. Trial 1 compared pregnant and open cows (n=4) from January to March 1989; trial 2 compared pregnant cattle (n=4) that received either 9 kg alfalfa hay head-1 day-1 or 1.4 kg alfalfa pellets head-1 day-1 from December 1989 to February 1990. Diets were estimated using both bite counts and fecal analysis. During trial 1, bite counts revealed pregnant and open cows consumed 45 and 42% of their grazing diets as pine needles (P>0.1). Fecal analysis showed that pregnant cows consumed more pine needles than did open cows (36% vs. 27%, respectively) (P<0.05). During trial 2, cattle consumed < 1% of their diets as pine needles. In trial 1 cattle consumed less pine litter and consumed more needles from trees as snow depth increased. Consumption of needles from trees increased as ambient temperature declined; no needles were consumed from trees when the minimum daily temperature exceeded -5” C. During both trials, grazing times decreased as temperatures declined, and increased as snow depth and wind speed decreased. We conclude that weather is a major factor influencing needle consumption; other interrelated factors may be forage availability, snow cover, and grazing time. Plne needle consumption, and the risk of abortion, in pregnant cattle appears to be greatly diminished during mild winter weather.
    • Factors Influencing Productivity of Two Mule Deer Herds in Utah

      Pederson, J. C.; Harper, K. T. (Society for Range Management, 1978-03-01)
      Doe-fawn counts show that the mule deer herd on the LaSal Mountains of southeastern Utah produced over 38% more fawns per doe than the Henry Mountain herd over a 9-year period. Carcass weights of animals from the LaSal herd were generally greater for all age classes. Observed reproductive differences appear to be unrelated to the incidence of diseases, parasites, or predation. Furthermore, winter ranges are nearly equal in forage quantity and quality on the two ranges. Summer range vegetation on the LaSal Mountains, however, produced more forage of better quality than did similar community types on the Henry Mountains. LaSal summer ranges produced 2,149 kg/ha fresh weight of available forage while similar ranges on the Henrys produced only 1,314 kg/ha. Forbs account for 52% of the forage on LaSal summer ranges but only 12% of the forage on ranges of comparable elevation on the Henrys. The data suggest that the characteristics of the forage found on the summer range, especially the quantity and quality of forbs, exert important influences on productivity of these herds.
    • Factors Influencing the Feed Intake and Live-Weight Change of Beef Cattle on a Mixed Tree Savanna in the Transvaal

      Zimmermann, I. (Society for Range Management, 1980-03-01)
      This study was conducted as part of a broad ecosystem project to identify and quantify some of the significant relationships between cattle and their environment. Over a period of 1 year, monthly measurements were made of Africander cattle ranging on mixed tree savanna in the Transvaal, Republic of South Africa. The following data were obtained: feed intake, liveweight change, crude protein content (CP) and digestibility of the diet, as well as the time which was spent feeding and mean bite size. Both CP and digestibility of diets influenced the liveweight change of the cattle, but only digestibility influenced their feed intake. Their daily feeding time was short enough and their mean bite size was large enough to suggest that the accessibility and distribution of preferred plant species within the savanna did not directly limit their feed intake. Nutritional requirements of the cattle could be estimated from relationships between some of the factors, the most accurate relationship being that between digestible CP intake and liveweight change of the cattle.
    • Factors Influencing the Selection of Resting Sites by Cattle on Shortgrass Steppe

      Senft, R. L.; Rittenhouse, L. R.; Woodmansee, R. G. (Society for Range Management, 1985-07-01)
      Spatial patterns of cattle resting behavior were investigated on shortgrass steppe. Resting was divided into daytime and nighttime categories. Sites selected for daytime resting during June through August were low-lying areas, fencelines, and stock-water area. Daytime resting during September through May occurred on south-facing slopes and lowland areas. Degree of use of warm slopes varied from month to month, peaking in midwinter. A significant portion of daytime resting occurred near water (23%) and fencelines (27%) at all times of the year. Resting at night during October through May occurred on south-facing slopes, low-lying areas, sites with sandy soils, and sites with high buffalo grass (Buchloe dactyloides) cover. During June through September, cattle preferred sites on east-facing slopes and on lowlands. Cattle rested near fencelines less at night than during the day. Patterns of and factors correlated to resting were different from those associated with grazing activity. Resting behavior was correlated with topographic variables, whereas previous work has shown grazing to be correlated with vegetation variables.
    • Factors Involved in Estimating Green Biomass by Canopy Spectroreflectance Measurements

      Waller, S. S.; Brown, M. A.; Lewis, J. K. (Society for Range Management, 1981-03-01)
      Factors involved in estimating dry green biomass (DGB) by canopy spectral reflectance were evaluated at six dates during the 1976 growing season. In situ measurements were taken in the Mixed Prairie of western South Dakota on replicated pastures in different range condition classes using a modified hand-held biometer. Canopy reflectance and calibration panel reflectance were determined at 0.675 μm and 0.800 μm. Factors considered in estimating DGB via stepwise multiple regression were the canopy reflectances, calibration panel reflectances, time of day, and coefficient of variability among vegetation samples in a pasture. Canopy reflectance readings were included as both a ratio of the two wave lengths and as two separate variables in two sets of analyses. Canopy reflectance readings alone were not acceptable estimates of DGB (R2=.029 for the ratio and .042 for the linear combination). The coefficient of variability of samples within a pasture improved the association (R2=.233 and .231) while further inclusion of both calibration readings resulted in a marked improvement in estimation of DGB (R2=.633$ and .899). These calibration readings corrected for sun angle and diffuse cloud cover so that time of day of measurement was not an important variable.
    • Factors Involved in the Decline of Annual Ryegrass Seeded on Burned Brushlands in California

      Papanastasis, V. (Society for Range Management, 1976-05-01)
      The effect of amount of mulch, nitrogen fertilizer, and clipping frequency was studied on herbage and seed production of annual ryegrass (Lolium multiflorum Lam.) seeded on a burned brushland in California. The experiment was continued for 2 years but, in the second year, actual grazing by meadow mice (Microtus californicus) was substituted for the clipping treatment. Available nitrogen in the soil was found deficient in both years but the deficiency was more pronounced in the relatively dry year. Meadow mice reduced herbage and seed yields significantly in the second year. It is concluded that the decline of annual ryegrass in burned brushlands is associated with a corresponding decline through immobilization of available soil nitrogen released by brush burning.
    • Factors Limiting Liveweight Gain of Beef Cattle on Rangeland in Botswana

      Pratchett, D.; Capper, B. G.; Light, D. E.; Miller, M. D.; Rutherford, A. S.; Rennie, T. W.; Buck, N. G.; Trail, J. C. (Society for Range Management, 1977-11-01)
      Six range parameters measured monthly over an 11-month period on nine ranches distributed throughout the main ecological zones of Botswana were related to the monthly liveweight changes of growing cattle. Clipped and esophageal fistula samples provided estimates of crude protein content (CP) and dry matter digestibility (DM), while available DM and grazing index provided estimates of available herbage. Linear, quadratic, and multiple regressions all indicated that liveweight change was influenced primarily by the CP content of the herbage selected. The CP content of fistula samples accounted for 54% of the variation in liveweight gain, while digestibility of the same samples accounted for 32%. Quadratic regressions failed to account for any more variance than linear regressions. The inclusion of digestibility with CP content in a multiple linear regression failed to have any effect. The addition of grazing index to CP content increased the variance accounted for in both the fistula and clipped samples from 54% to 56% and 48% to 53%, respectively. It appears that under the natural range conditions of Botswana, crude protein is presently the major limiting factor, and initial research efforts must be directed towards increasing the CP content of the diet available to beef cattle.
    • Factors to Consider in the Evaluation of Vegetation Condition

      Costello, D. F. (Society for Range Management, 1956-03-01)