• The Effect of Light and Moisture on Columbia Milkvetch Toxicity in Lodgepole Pine Forests

      Majak, W.; Parkinson, P. D.; Williams, R. J.; Looney, N. E.; Van Ryswyk, A. L. (Society for Range Management, 1977-11-01)
      Variations in miserotoxin concentration of Columbia milkvetch located in pure lodgepole pine forests were compared to changes in rainfall patterns during the period 1973 to 1976. The substantial increase in precipitation for 1976 was reflected in soil and plant moisture changes and these conditions appeared to induce the formation of higher miserotoxin levels. In addition, a number of secondary miserotoxin peaks were generated during pod development in 1976. Understory light regimes at 12 lodgepole pine sites were determined by chemical actinometry, which expressed duration in direct sun at each plot as a percentage of "full sun" (FS) control. Sites with <15% FS exhibited lower miserotoxin levels than either the 15-35% or >35% FS groups. Miserotoxin levels above 6% predominated in the latter two categories. A positive relationship between light and toxicity was not apparent in the Douglasfir stands where miserotoxin levels remained low. A gas chromatography method was developed to speed up miserotoxin determinations and to screen Columbia milkvetch samples for the presence of free 3-nitropropanol.
    • Species Adapted for Planting Arizona Pinyon-Juniper Woodland

      Lavin, F.; Johnsen, T. N. (Society for Range Management, 1977-11-01)
      Species adaptation trials were observed over periods varying from 21 to 28 years at ten Arizona pinyon-juniper sites. Fifty-nine species and varieties developing fair to excellent stands and persisting five or more years were considered adapted to one or more of the sites. Fifty-four of these were still present at the last rating. Thirty have reproduced themselves and are spreading naturally. Most widely adapted species are Agropyron desertorum, A. intermedium, A. smithii, A. trichophorum, Atriplex canescens, Bothriochloa ischaemum, Bouteloua curtipendula, Muhlenbergia wrightii, and Tridens elongatus. Moisture variation caused some cool season grasses to fluctuate more widely in growth and stand than the other adapted species, especially shrubs. Warm-season growers were generally sensitive to low temperatures and cool-season growers to high temperatures. Complete protection from livestock appeared to have detrimental effects on some species. Sites are described and classified to help identify planting potential and facilitate wide application of results. Guidelines are suggested for shortening the time period needed to evaluate species adaption.
    • Some Range Relationships of Feral Goats on Santa Catalina Island, California

      Coblentz, B. E. (Society for Range Management, 1977-11-01)
      Some aspects of forage production, utilization, and percent cover were studied on Santa Catalina Island from July 1971 through April 1973. Food habits of feral goats (Capra hircus) were examined in December 1974 and May 1975. During May 1975 herbaceous vegetation comprised 92% of the diet of the goats. It was proposed that goats are not primarily browsers by preference, but are opportunistic generalists and tend to consume the most palatable vegetation available. Significant vegetational differences are found between adjacent goat-inhabited and goat-free areas of the island. It was concluded that precise ecological knowledge is needed to properly manage both domestic and feral goats.
    • Selecting Letter Sizes for Technical Data Slides

      Walkowiak, B. J.; Ries, R. E. (Society for Range Management, 1977-11-01)
      Careful selection of letter size and amount of information to be included before photographing slides is essential for legible slides. This article presents information that can be used to select the correct size of lettering for a specific drawing size before drafting and photographing them so as to insure that the 2 × 2 inch slides produced will be legible even to those sitting in the back of the audience.
    • Seed Germination of True Prairie Forbs

      Voigt, J. W. (Society for Range Management, 1977-11-01)
      A study was conducted on 20 species of prairie forbs collected from Illinois tallgrass prairie to determine their levels of germination without treatment of the seed and to determine their expected higher levels of germination with various seed treatments. The present assay of forb seed germination was made to aid those engaged in prairie restoration. Seed fill was visually and physically determined. Seed viability was determined by use of triphenyl tetrazolium chloride, which turns living embryos red. Germination was done on moist filter paper inside petri plates in darkness at constant temperature. From tests on 20 species only three germinated without treatment; 12 germinated under 2 months of moist-cold treatment; and four germinated with scarification. When treated with rootone, five species germinated. Three species germinated with single application of .005% potassium gibberellate spray. These results suggest most of the 20 species could be planted with success with the proper preparation or treatment of the seed.
    • Responses of Game and Nongame Wildlife to Predator Control in South Texas

      Guthery, F. S.; Beasom, S. L. (Society for Range Management, 1977-11-01)
      One hundred thirty-two coyotes, 27 opossums, 22 skunks, 18 bobcats, 15 raccoons, 12 badgers, and one gray fox were killed on a 1,550-ha area of mixed brush rangeland in South Texas during January-July 1975 and 1976 to determine the responses of herbivore and quail populations to predator control. When compared to an area without predator control, predator removal at this level had little discernible effect on density trends of bobwhite or scaled quail, rodents, or lagomorphs. However, fawn production per unit area was 70% greater in 1975 on the area with predator control and 43% greater in 1976. These data suggest that intensive short-term predator control on South Texas rangeland results in little or no adverse impact on range forage due to expanding populations of small herbivores. Productivity and populations of white-tailed deer may increase and harvests should be adjusted accordingly, as overuse of range forage could occur.
    • Range Management Theses 1968-1975

      Pieper, R. D. (Society for Range Management, 1977-11-01)
    • Possible Effects of Weather Modification (Increased Snowpack) on Festuca idahoensis Meadows

      Weaver, T.; Collins, D. (Society for Range Management, 1977-11-01)
      When compared with undrifted sites, meadow sites with artificially induced drifts have shorter growing seasons, higher average growing season temperatures due to the absence of a cool spring, similar growing season soil water availabilities, and slightly less available nutrients due to leaching. Community composition, plant production, and plant phenology were affected slightly by doubling snow pack to 12-dm and were affected considerably by quadrupling snow pack to 24-dm. Though larger increases in snowfall might, it seems unlikely that 20-30% increases in winter precipitation would significantly affect the vegetation of Festuca idahoensis meadows.
    • Optimum Size and Shape of Quadrat for Sampling Herbage Weight in Grasslands of Northern Greece

      Papanastasis, V. P. (Society for Range Management, 1977-11-01)
      Five quadrat sizes, 0.0625, 0.125, 0.250, 0.500, and 1 square meter and three shapes, square, rectangular, and circular were tested in an ungrazed foothill bunchgrass range of northern Greece to determine the optimum quadrat for sampling herbage yield. Data on total herbage weight and clipping time were collected, which showed a high degree of variability. Shapes did not produce significantly different results. Larger quadrats were more efficient statistically but less efficient timewise than smaller quadrats. By maximizing the product of statistical and time efficiency, it was found that a quadrat of 0.0625 m2 of any shape was the optimum quadrat for herbage weight estimates.
    • Measuring Soil Compaction on Rangeland

      Gifford, G. F.; Faust, R. H.; Coltharp, G. B. (Society for Range Management, 1977-11-01)
      Several instruments used for measuring soil compaction have been evaluated on a homogeneously-textured, nongravelly silt-loam soil. The instruments used in the study were the air permeameter, proving ring penetrometer, volumeasure, pocket penetrometer, and gamma ray scattering device. Correlation coefficients and regression equations were developed between each instrument and bulk density as determined by the soil core method. Readings from all instruments were significantly correlated with soil core bulk density. The two instruments which had the highest correlation with bulk densities during initial testing, the air permeameter and the proving ring penetrometer, were further evaluated on a rangeland soil. In this instance, predicted bulk densities (using the above regression equations) from air permeameter readings correlated better with soil core bulk densities than did predicted bulk densities from proving ring penetrometer readings.
    • Herbicides, Nitrogen, and Control of Tall Larkspur under Aspen Trees

      Cronin, E. H.; Bowns, J. E.; Johnson, A. E. (Society for Range Management, 1977-11-01)
      Tall larkspur (Delphinium barbeyi Huth.) dominates the herbaceous vegetation under quaking aspen (Populus tremuloides Michx.) on large areas of mountain summer ranges in southern Utah. These tall larkspur plants are more susceptible to single applications of 2,4,5-T and silvex than reported for the same species growing in the open subalpine meadows of central Utah. The herbicide treatments evaluated provide a means of manipulating the vegetation to produce various proportions of grasses and forbs that would be safe and desirable for cattle or for dual use by cattle and sheep. Nitrogen fertilization applied in addition to herbicide treatments did not enhance control of tall larkspur or stimulate forage production. High rates of nitrogen applied to otherwise untreated plots did not control tall larkspur, and increased forage production only the first year after application.
    • Grama (Bouteloua Lag.) Communities in a Southeastern Arizona Grassland

      Nicholson, R. A.; Bonham, C. D. (Society for Range Management, 1977-11-01)
      Fifty stands, representing six common and three rare species of gramas (genus Bouteloua), were sampled for vegetation abundance, species composition, and selected habitat factors. Numerical and statistical procedures were used to aid in obtaining succinct descriptions of the habitat structure of the grama species. Factors such as texture and content of various nutrients of the soils were among those that showed trends. Black grama (B. eriopoda) was found to be associated with soils higher in nitrate, potassium, organic matter, pH, and lime. Most similar to stands of black grama were stands of eludens grama (B. eludens) and sideoats grama (B. curtipendula), which tended to also be associated with sandy clay textured soils and steep, rocky slopes. All stands of eludens grama were found on southerly exposures. Hairy grama (B. hirsuta) and spruce-top (B. chondrosiodes) were most widely distributed and tended to occur together on relatively level sites with clayey, acidic soils. Curly mesquite (Hilaria belangeri) was nearly always associated with these two gramas. Blue grama (B. gracilis) tended to be most abundant on acidic, relatively infertile, sandy clay loam soils.
    • Forage Yields of Five Perennial Grasses with and without White Clover at Four Nitrogen Rates

      Dobson, J. W.; Beaty, E. R. (Society for Range Management, 1977-11-01)
      One of the current interests in cattle production research is the inclusion of a legume which might be expected to increase forage yields and reduce the need of N fertilization. The clover should lengthen the growing season over that of straight grass. An investigation measured the influence of white clover on grass forage yields where perennial grass species were grown at four N rates with and without white clover (Trifolium repens L.). White clover/perennial grass mixtures were superior to grass/N, and including clover significantly increased forage yields at N rates up to 112 kg/ha. Only when 336 kg N/ha was applied were average yields of clover/grass and grass/N comparable. The average increase in forage yields when clover was added to the perennial grasses at the 0, 37, 112, and 336 kg/ha N rates was 218.9%, 93.0%, 34.1%, and 0.2%, respectively. Clover production was concentrated in the first 7 months of the season and dropped sharply in August and September. Average clover/grass yields were consistently higher over the 4 years than were grass/N yields. White clover should be included in grass mixtures grown in Southern pastures to reduce the need for N fertilization.
    • 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.
    • Economics of Tall Larkspur Control

      Nielsen, D. B.; Cronin, E. H. (Society for Range Management, 1977-11-01)
      Tall larkspur (Delphinium barbeyi Huth.) was chemically controlled in the subalpine areas of the Manti Canyon Cattle Grazing Allotment in Central Utah, and the reduction in cattle losses on controlled areas was observed. Without control, an average of 36 mature cattle were lost per year over a 15-year period, and an average of 11 calves were lost per year over an 8-year period. Cost of control ranged from $15-$22 per acre of larkspur for the first application, and from $13-$17 per acre for the second application. Cattle losses were reduced over 90% in the sprayed pastures. Thus, the estimated annual value for adult cattle saved was $8,250 and for saved calves it was $1,200. Internal rates of return ranged from 72.25% to 60%, with the rate dependent upon whether calves saved were included. A return of 10% can be expected from larkspur control if eight to nine cows are saved each year for 10 years.
    • Canopy Reflectance and Film Image Relations among Three South Texas Rangeland Plants

      Gausman, H. W.; Everitt, J. H.; Gerbermann, A. H.; Bowen, R. L. (Society for Range Management, 1977-11-01)
      Field spectroradiometric measurements for canopy reflectances of three dominant south Texas woody plants (cenizo, honey mesquite, live oak) were used successfully to predict their color infrared film images and distinguishability: cenizo, whitish; honey mesquite, relatively light magenta; and live oak, darker magenta.