Now showing items 1-20 of 80672

    • Winter Variation in Nutrient and Fiber Content and In vitro Digestibility of Gambel Oak (Quercus gambellii) and Big Sagebrush (Artemisia tridentata) from Diversified Sites in Colorado

      Kufeld, R. C.; Stevens, M.; Bowden, D. C. (Society for Range Management, 1981-03-01)
      Nutrient and fiber content and in vitro digestible dry matter (IVDDM) were measured in Gambel oak (Quercus gambellii) and big sagebrush (Artemisia tridentata) samples collected during January from nine geographic areas distributed widely throughout the western half of Colorado, and representing three vegetation types. Coefficients of variation among areas were less than 10% in both species in dry matter content, IVDDM and most cell and cell wall components. Variation appears to be small enough to permit application of a suitably selected, constant value, which would reflect winter nutrient content, fiber content or digestibility of these species, regardless of where collected in Colorado, in surveys where winter nutritional status of big game rangelands is being estimated for management purposes.
    • Wildlife Habitat on Grazed or Ungrazed Small Pond Shorelines in South Texas

      Whyte, R. J.; Cain, B. W. (Society for Range Management, 1981-01-01)
      Three man-made ponds constructed in 1956 and fenced to exclude cattle from the shoreline were selected to study the effects of cattle on shoreline vegetation. These ponds were partially opened in 1977 to allow grazing on one-half of the shoreline. The vegetation was sampled monthly with an inclined 10-point frame placed at 1-m intervals along transects in the opened and fenced sections of the shorelines. In most areas the foliar cover and vegetation height were reduced by cattle pressure. The stable Long-tom Community and the Knotgrass-Smartweed Community were more affected by cattle pressure than the Transition Community which changed as the water level rose or dropped. The seasonal Aquatic Community was least affected by cattle pressure and thus maintained good stands of waterfowl food plants. Carefully planned grazing which allows key rest and grazing periods will control the impact of grazing on the shoreline vegetation. Stable waterfowl habitat on the shorelines of small man-made ponds in South Texas can best be protected by fencing at least one-half of the shoreline to restrict cattle use.
    • White-tailed Deer Diets from Pastures in Excellent and Poor Range Condition

      Bryant, F. C.; Taylor, C. A.; Merrill, L. B. (Society for Range Management, 1981-05-01)
      A study was initiated in August, 1975, to examine the forage available to and diet composition of white-tailed deer on pastures of excellent and poor range condition at the Sonora Research Station near Sonora, Texas. Grass and forb standing crop and deer feeding time on these two forage classes were considerably higher on the pasture in excellent range condition than that in poor range condition. Browse standing crop and feeding time was greater from the pasture in poor range condition. The Merrill 4-pasture grazing system appeared to increase the availability and use by deer of grass regrowth. Yearly averages of crude protein and phosphorus were higher in diet samples collected from the pasture in excellent range condition. Digestible energy levels were similar between pastures when averaged over the 1-year period. Digestible energy levels in diets were, however, higher from the excellent condition pasture in every season except winter. In winter, deer fed primarily on the foliage of oak on excellent condition range; but on the pasture in poor range condition, deer used large amounts of foliage and mast from juniper and dead leaves of persimmon in addition to oak foliage. Juniper and persimmon apparently contributed to the higher digestible energy levels observed on the pasture in poor range condition during the winter season. Energy may be a major nutrient limiting deer production on the Edwards Plateau.
    • White-Tailed Deer Densities and Brush Cover on the Rio Grande Plain

      Steuter, A. A.; Wright, H. A. (Society for Range Management, 1980-09-01)
      Rio Grande Plain habitats with a range in total brush cover from 10 to 97% were selected from three brush control treatments and native brush types. Deer density in each habitat was determined from helicopter census and observation towers. Three brush cover classes resulted in three levels of white-tailed deer use during summer. Areas with less than 43% total brush cover had a maximum density of 1.4 deer/40.5 ha. Brush cover from 43 to 60% had a maximum density of 3.25 deer/40.5 ha. Highest summer deer use occurred on areas with 60 to 97% total brush cover (7.5 deer/40.5 ha).
    • 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.
    • Vegetation Development over 25 Years without Grazing on Sagebrush-dominated Rangeland in Southeastern Idaho

      Anderson, J. E.; Holte, K. E. (Society for Range Management, 1981-01-01)
      Data from permanent vegetation transects, established on the Idaho National Engineering Laboratory Site in 1950, were analyzed to determine what changes had taken place in the vegetation complex over the past 25 years in the absence of grazing by domestic livestock. Cover of shrubs and perennial grasses has nearly doubled. Shrub cover in 1975 was 154% greater than in 1950; this change was almost entirely due to increases in cover of big sagebrush between 1957 and 1965. Cover of perennial grasses increased exponentially over the 25-year period, from 0.28% in 1950 to 5.8% in 1975. This was paralleled by significant increases in density and distribution of the four most important grasses on the study area. The 20-fold increase in perennial grass cover has not been at the expense of the shrub overstory. There was no obvious correlation between trends for perennial grass cover and precipitation patterns. Rather, the exponential growth is believed to reflect the availability of seeds as formerly depleted populations increase in size. No evidence of seral replacement, as predicted by classical succession, was found. The data seem more consistent with the "initial floristics/relative stability" concepts of vegetation development.
    • Using Sodium Carbonate to Seal Leaky Stock Ponds in Eastern Montana

      Neff, E. L. (Society for Range Management, 1980-07-01)
      Mixing sodium carbonate into the top 100 to 150 mm of soil in three farm ponds constructed in calcareous soil in eastern Montana effectively reduced seepage losses for about 3 years following treatment. Seepage rates the first year after treatment were decreased to 20 to 40% of the pretreatment rate, but they were 60 to 100% of the pretreatment rate 4 years after treatment.
    • Use of a Profile Board in Sand Shinnery Oak Communities

      Guthery, F. S.; Doerr, T. B.; Taylor, M. A. (Society for Range Management, 1981-03-01)
      A profile board adapted to sand shinnery oak communities gave highly accurate structural profiles of the vegetation. Using actual estimates of percentage screening of strata by foliage was more accurate than using percentage screening classes. The procedures used to adapt the profile board to sand shinnery oak communities can be used in other plant communities.
    • Understory Biomass Response to Microsite and Age of Bedded Slash Pine Plantations

      Ball, M. J.; Hunter, D. H.; Swindel, B. F. (Society for Range Management, 1981-01-01)
      Understory standing crop biomass was studied on three culturally imposed microsites (bed, furrow, and flat) bedded slash pine (Pinus elliottii) plantations in north Florida. Biomass was clipped in the late spring of 1977 on plantations 2, 5, and 10 years old and separated into five classes: grass, forb, sedge, shrub, and litter (including standing dead). After an initial abundance following site preparation sedges and forbs dropped to relatively low levels within the first 5 years of plantations development. Grasses were the dominant live vegetation in two-year-old plantations. Shrubs became dominant by the fifth year and remained so through the 10th year. Litter, as a result of the lack of cultural treatments designed to remove accumulated dead vegetation, was the major biomass class (more than 8,000 kg/ha by the fifth year following pine establishment). Total live understory biomass increased from the second to the fifth year after which it decreased. Grass standing crop biomass was highest on the flats, lowest in furrows. Hence, forage inventories should be stratified by microsite. Prescribed burning on a properly managed cattle operation may prevent high accumulations of litter while effectively improving the availability of palatable forage. Forage may also be increased by decreasing the proportion of land occupied by the less productive microsites, namely the furrows and beds.
    • Translocation and Storage of 14 C-labled Total Nonstructural Carbohydrates in Honey Mesquite

      Fick, W. H.; Sosebee, R. E. (Society for Range Management, 1981-05-01)
      Translocation of total nonstructural carbohydrates (TNC) in mature honey mesquite (Prosopis glandulosa var. glandulosa) trees was studied by photosynthetically incorporating 14 CO2 on eight dates during the summer of 1975. Several plant parts were analyzed for TNC and relative total activity (RTA) to determine direction of translocation and sink strength. Stem and twig TNC fluctuated more than basal bud TNC in response to phenological development. Pods were generally the strongest TNC sink except during initial pod formation (June 25), when bidirectional translocation occurred and all plant parts sampled contained equal concentrations of the 14 C label. A RTA/TNC ratio used in conjunction with RTA and TNC suggested that increased TNC concentrations in the pods and stems may not always be due to increased import of TNC but caused by a reduction in growth with constant importation. Greatest translocation of TNC to the basal buds occurred between the phenological stages of green flower spikes (June 10) and pod formation (June 25) and during pod maturation (August 4 to August 19).
    • Transforming a Traditional Forage/Livestock System to Improve Human Nutrition in Tropical Africa

      Sullivan, G. M.; Stokes, K. W.; Farris, D. E.; Nelsen, T. C.; Cartwright, T. C. (Society for Range Management, 1980-05-01)
      Livestock systems based on uncontrolled communal grazing result in inefficient utilization of native forages and low livestock production. Forage/livestock herd simulation models are adapted to Tanzania to evaluate a case of improved technology. A hay enterprise for lactating cows, not possible with uncontrolled communal grazing, was found to increase nutritional and monetary welfare of a typical village.
    • Toxicity and Control of Kelsey Milkvetch

      Cronin, E. H.; Williams, M. C.; Olsen, J. D. (Society for Range Management, 1981-05-01)
      Kelsey milkvetch (Astragalus atropubescens Coult. and Fish.) contains miserotoxin (β-glucoside of 3-nitro-1-propanol). Chemical analyses and biological evaluations indicated moderately low concentrations of the toxin in this species. However, this plant has been implicated in cattle losses and a potential danger of both acute and chronic poisoning exists on grazing areas where kelsey milkvetch grows in abundance. It grows in mountainous areas in the Salmon River drainage in Idaho and the Big Hole River drainage in Montana. Kelsey milkvetch was controlled with an application of 2.24 kg/ha (2 lb/ac) of 2,4,5-T[2,4,5-tricholorophenoxy)acetic acid] and eradicated with an application of silvex [2-(2,4,5-tricholorophenoxy)propionic acid].
    • Townsend Ground Squirrel Diets in the Shrub-Steppe of Southcentral Washington

      Rogers, L. E.; Gano, K. A. (Society for Range Management, 1980-11-01)
      Microscopic study of fecal pellets from Townsend ground squirrels occupying the shrub steppe region of southcentral Washington showed that squirrels preferred to feed on bluegrass (Poa sp.) and forbs (Descurainia pinnata and Lupinus laxiflorus); phlox (Phlox longifolia) may also be a favored food item. Bluebunch wheatgrass (Agropyron spicatum), six-weeks fescue (Festuca octoflora), and lomatium (Lomatium macrocarpum) were avoided. No significant differences between diets of ground squirrels occupying grazed and ungrazed study areas or between diets of male and female or adult and subadult ground squirrels were found.
    • The Effects of Subsurface Irrigation on Current and Subsequent Year's Growth in Shadscale

      Johnson, P. S.; Norton, B. E. (Society for Range Management, 1980-09-01)
      Sursurface irrigation of individual Atriplex confertifolia (shadscale) plants was implemented in the field during the summer of 1976 through the use of vertical access tubes to a depth of 50 cm. Shoots were marked on control and watered plants and examined periodically by enumerating every leaf, bud, flower, fruit, and second-order stem. Plant response to subsurface irrigation as determined in the fall enumeration revealed a modest increase in stem length and leaf weight and summer production of lateral branches. The carryover effect of summer irrigation was reflected in new growth on shoots of watered plants in spring 1977 being more than twice the production of shoots on controls. The 1976 response to subsurface irrigation is thought to be carbohydrate storage and/or root development. Watering did not enhance bud or shoot survival overwinter.
    • The Effects of Fall Defoliation on the Utilization of Bluebunch Wheatgrass and Its Influence on the Distribution of Deer in Spring

      Willms, W.; Bailey, A. W.; McLean, A.; Tucker, R. (Society for Range Management, 1981-01-01)
      Deer and cattle grazing in spring preferred bluebunch wheatgrass plants that had been defoliated the previous fall to those that had not. Deer selected burned plants in greater proportion than grazed plants. Fall grazing by cattle affected the distribution of deer. Deer displayed preference for the fall grazed field after green growth exceeded the height of stubble.
    • The Effect of Strip Width on Helicopter Censusing of Deer

      Beasom, S. L.; Hood, J. C.; Cain, J. R. (Society for Range Management, 1981-01-01)
      Evaluation of the numbers of white-tailed deer observed in the first (inside) 50 m compared to the second (outside) 50 m strips from helicopter census transects on brush-covered rangelands in Texas revealed from 34-73% fewer animals in the latter. The average reduction of approximately 53% suggests that helicopter censuses yield density estimates about 25% low. Correction for these underestimates could lead to more efficient management of the resource as well as elevated income in areas commercializing hunting.
    • The Binary Search for Accuracy in Plant Symbols

      Gibbens, R. P.; Bilan, T. N. (Society for Range Management, 1981-05-01)
      The transfer of data from field sheets to computer files always involves the risk of errors being made in plant symbols or other identifying codes. If a master list of symbols or codes is incorporated into the software programs used for data entry on CRT computer terminals the risk of making errors can be substantially reduced. This is done by utilizing the highly time efficient binary search to compare each entered symbol or code with the master list. Detection of errors before the data are transferred to computer files saves much time which would otherwise be spent in retrieving and correcting files.
    • Tetraploid Perennial Teosinte Seed Dormancy and Germination

      Mondrus-Engle, M. (Society for Range Management, 1981-01-01)
      Tetraploid perennial teosinte is an endangered Mexican relative of maize with potential for use as a tropical rangeland and permanent pasture forage. Seeds are dormant when harvested, becoming more germinable as they afterripen. New-seed dormancy may be broken by pre-soaking seed in a gibberellic acid solution. Other pre-treatments are less effective or inhibit germination. Seeds enclosed in white fruitcases are less germinable than those in dark fruitcases, and frequently lack developed embryos./El teosinite tetraploide perenne es una gramínea rara, indígena a México y afín al maíz, que se puede utilizar en los pastizales y pastos permanentes tropicales. Las semillas están en estado durmiente al cosechar, y aumenta la germinación después de un período de maduración. El período durmiente de las semillas se puedc terminar por medio de remojarlas en una solución del ácido giberélico. Otros medidas de terminar el período durmiente son menos efectivas o impiden la germinación. Las semillas blancas son menos capaz de germinar que las de color oscur, y frecuentemente carecen del embrión.
    • Temperature Profiles for Germination of Bluebunch and Beardless Wheatgrasses

      Young, J. A.; Eckert, R. E.; Evans, R. A. (Society for Range Management, 1981-03-01)
      The germination of seeds of beardless and bluebunch wheatgrasses was investigated over a wide range of constant and alternating temperatures. Seeds of 'Whitmar' beardless wheatgrass, a collection from Nevada, and numbered accessions of bluebunch wheatgrass were used. Seeds of 'Whitmar' beardless wheatgrass germinated at 87% of the 55 temperature regimes tested with a mean germination of 52%. Germination at 42% of the temperature regimes was optimum [defined as not significantly (P = 0.01) different from maximum], with a mean of 84%. Freshly harvested seeds of the Nevada source of bluebunch wheatgrass germinated at 78% of the temperature regimes with a mean of 40%. Comparable figures for fully ripened seeds 5 months after harvest were 84% with a mean of 62%. The germination response of 1-month old bluebunch wheatgrass seeds indicated that germination could occur at the high seedbed temperatures encountered in a late summer moisture event. The temperature-germination profiles for the numbered accessions of bluebunch wheatgrass had the same general pattern as the Nevada source. Generally, seeds were highly germinable at a number of temperatures. Optimum germination of all the sources of seed occurred at 37 temperature regimes at least once and always occurred at 15 temperatures ranging from an alternating 5/15 degrees C through a constant 25 degrees C. This range of germination temperatures is much wider than that exhibited by squirreltail and Sandberg bluebunch. The bluebunch wheatgrass material has the inherent potential to germinate and to be highly germinable at a wide range of temperatures.
    • Susceptibility of Selected Woody Plants to Pelleted Picloram

      Kitchen, L. M.; Scifres, C. J.; Mutz, J. L. (Society for Range Management, 1980-09-01)
      Picloram pellets, aerially applied at 1.1 kg/ha in the spring to South Texas mixed-brush, effectively controlled spiny hackberry and pricklypear, and 2.2 kg/ha temporarily controlled blackbrush acacia. However, agarito, desert yaupon, lotebush, Texas persimmon, and whitebrush were only slightly susceptible to soil applications of picloram, and honey mesquite and creeping mesquite were tolerant. Range site exerted a significant influence only with initial defoliation of twisted acacia. Although canopy reduction of twisted acacia after one growing season was higher on Shallow than on Rolling Blackland or Claypan Prairie range sites, it was apparently only moderately susceptible to pelleted picloram. Shredding prior to pellet applications did not improve the level of brush control compared to applying the picloram to undisturbed brush stands. There was no consistent difference in brush control within an application rate between 5% or 10% active ingredient formulations of picloram pellets.