• Yield, Vigor, and Persistence of Sand Lovegrass (Eragrostis trichodes (Nutt.) Wood) Following Clipping Treatments

      Moser, L. E.; Perry, L. J. (Society for Range Management, 1983-03-01)
      Individual sand lovegrass [Eragrostis trichodes (Nutt.) Wood.] plants on a choppy sands range site in Nebraska's Sandhills were clipped with 7 different harvest regimes for 3 years to determine critical defoliation times. After 3 years unclipped plants had the greatest survival rate and plants harvested only once a year on June 10 or July 10 survived better than those with other harvest regimes. Top and root yields, new tiller counts, and total non-structural carbohydrate (TNC) levels were all reduced severely with multiple harvests within one year. Sand lovegrass plants cannot tolerate close defoliation at anytime of the year although a single June defoliation appeared to be less detrimental than August defoliation. Sand lovegrass is difficult to manage when it makes up a small component of a pasture. Sand lovegrass will probably persist and yield best in a rotational grazing program where it is defoliated only once a year and some leaf area remains at the close of the grazing period. Plants are normally short lived so they should be managed to allow seed production periodically. A grazing management program necessary to maintain small amounts of sand lovegrass in a mixture may not be practical.
    • Topographic and Habitat Use by Sympatric Barbary Sheep and Mule Deer in Palo Duro Canyon, Texas

      Simpson, C. D.; Gray, G. G. (Society for Range Management, 1983-03-01)
      The topographic distribution of sympatric populations of Barbary sheep and mule deer was studied in the Dry Creek branch (65 km2) of Palo Duro Canyon in the central Texas Panhandle from February 1977 through January 1979. Each of 529 Barbary sheep sightings and 337 mule deer sightings were recorded by topographic level and nonparmetric tests were used to evaluate the null hypothesis of no significant difference in distribution between Barbary sheep and mule deer in topographic level or habitat type. There was no significant difference between species in spatial usage on a monthly basis when sightings on Bluff Sites were compared with those on Level Sites. When sightings on High Sites were compared with those on Low Sites, distributional patterns were significantly different only for February and November. There were significant seasonal differences between species in distribution by habitat type during the autumn and spring, but the aggregate distribution of sightings suggested that overall usage of space was not significantly different. These findings, when considered with the results of comparative diet studies, indicate the possibility of competition for mutally preferred forage plants. Other implications are also discussed.
    • Spring Burning Effects on Redberry Juniper-Mixed Grass Habitats

      Steuter, A. A.; Wright, H. A. (Society for Range Management, 1983-03-01)
      Habitat and plant species parameters were compared among untreated, chained, chained/burned, burned/chained, and burned/chained/reburned treatments on redberry juniper-mixed grass rangeland. Chaining followed by burning with a standardized fire plan in mid-March drastically decreased shrub and debris cover, while increasing percentage bare ground. Perennial grass yields were maintained or increased compared to previously chained or untreated areas following burning in a year of above-normal rainfall. Burning in a "dry" year reduced grass yields by 50% of that on areas chained only, but yields were only slightly less than on untreated areas. Grass species density was reduced for 2 growing seasons following burning. Burning greatly reduced annual forbs from March through June of a moist spring. Total forb densities on burned areas were generally similar to, or higher than, those on unburned treatments by July because of extended growth of perennial forbs. March burns appeared to have the most severe impact on the least desirable shrub (redberry juniper), grass (threeawn), and forb (common broomweed) species.
    • Soil Movement in Mesquite Dunelands and Former Grasslands of Southern New Mexico from 1933 to 1980

      Gibbens, R. P.; Tromble, J. M.; Hennessy, J. T.; Cardenas, M. (Society for Range Management, 1983-03-01)
      Soil levels were marked on grid and transect stakes in mesquite duneland and grassland areas at 3 sites on the Jornada Experimental Range in 1933 and 1935. Soil levels on one set of transect stakes were remeasured in 1950 and 1955. Remeasurement of soil levels at both transect and grid stakes in 1980 revealed that extensive soil movement had occurred during the intervening years. On a 259-ha site containing large mesquite dunes in 1935, maximum deposition and deflation was 86.9 and 64.6 cm, respectively, in 1980. There was a net gain of 1.9 cm in soil depth over the entire area. On a 259-ha site only partially occupied by mesquite dunes in 1933, there was a net loss of 4.6 cm in soil depth and mesquite dunes had completely occupied the site by 1980. On a transect established across a mesquite duneland-grassland ecotone in 1935, there was a net loss in soil depth of 3.4 cm. Mesquite dunes had completely occupied the former grassland and dune intercept increased from 34.9 m in 1935 to 149.6 m in 1980. Gross erosion rates on wind deflated areas were equivalent to 69 tonnes ha-1 yr-1 on the area of large mesquite dunes. On the area partially occupied by mesquite in 1935 the gross erosion rate was 52 tonnes ha-1 yr-1. At the ecotone transect gross erosion rates were 45, 101, and 40 tonnes ha-1 yr-1 for 1935-50, 1950-55, and 1955-80 periods, respectively.
    • Shade Intensity Influences the Nutrient Quality and Digestibility of Southern Deer Browse Leaves

      Blair, R. M.; Alcaniz, R.; Harrell, A. (Society for Range Management, 1983-03-01)
      One deciduous and two broadleaf evergreen species of palatable deer browse were grown under three controlled levels of light reduction: 0, 55, and 92% shade. Determinations of nutrient composition and dry-matter digestibility were conducted on leaf tissues collected 7 months each year for 2 years. Throughout the year crude protein and the cell-wall constituents, acid-detergent fiber and cellulose, increased as shade deepened. Phosphorus and calcium levels, generally highest under deep shade, showed little difference in content between moderate shade or full sunlight. Reduced light did not affect the acid-detergent lignin content in deciduous dogwood leaves, but, in evergreen yaupon and honeysuckle, lignin content was highest in deep shade. Highly digestible cell solubles and apparent digestible energy content declined as shade increased. Dry-matter digestibility also declined as shade deepened, except the dry matter of dogwood leaves, either in full sun or in moderate shade, did not differ in metabolic usefulness. Seasonally, all leaves were most nutritious and digestible during spring refoliation. In winter, abscised and weathered dogwood leaves afforded little food value to deer, but the quality and digestibility of yaupon and honeysuckle leaves remained relatively high during this stress period.
    • Seed Germination Characteristics of Three Woody Plant Species from South Texas

      Everitt, J. H. (Society for Range Management, 1983-03-01)
      The seed germination of blackbursh (Acacia rigidula), guajillo (Acacia berlandieri), and guayacan (Porlieria angustifolia) was investigated in relation to temperature and various regimes of light; substrate salinity, pH, and osmotic potential; seed age; and site of seed source. Germination of blackbrush seed is restricted by an impermeable seed coat. Mechanical scarification or soaking seeds in concentrated sulfuric acid for 15 to 30 min increased blackbrush germination from 74 to 86%. Blackbrush, guajillo, and guayacan seed germination was best at about 25 degrees C. Blackbrush seed germination was not reduced by alternating as opposed to constant temperatures but germination of guajillo and guayacan was generally lower under alternating temperatures. Light was not required for germination. No seed dormancy mechanisms were observed other than the hard seed coat of blackbrush, and seed viability was not significantly reduced after 1 year in storage at room conditions. Guajillo seed collected from plants growing on a sandy loam site had higher percent germination than those of plants growing on a more droughtly clay loam site. Germination of blackbrush and guayacan from different sites did not differ. Germination and radicle length of seedlings were relatively tolerant of extremes of pH. Guajillo germination was significantly reduced in a aqueous solution of 2,500 ppm NaCl. Germination of blackbrush seed was not affected by 10,000 ppm NaCl, but guayacan seed germination was reduced at this concentration. Radicle lengths of seedlings of all species were significantly reduced at 10,000 ppm NaCl. Seed germination and radicle length of all 3 species were progressively decreased by increasing moisture stress up to -12 bars. Emergence of blackbrush and guajillo seedlings was not dependent upon burial in the soil; germination and emergence were greatest on the soil surface or from a depth of 1 cm.
    • Seasonal Variation in the Ignition Time of Redberry Juniper in West Texas

      Bunting, S. C.; Wright, H. A.; Wallace, W. H. (Society for Range Management, 1983-03-01)
      Seasonal variations in the moisture content, relative humidity, and average daily mean temperatures in the month preceding an ignition treatment were highly correlated to the length of preheating time required for ignition of green redberry juniper leaves during dry years. Ether extractives had no significant effect on ignition of green juniper leaves. During wet years, no correlation was found between any of the variables measured and ignition of green foliage. The data indicated that ignition was more easily predicted when the precipitation was below average than when it was above average, and that ether extract content was not a factor in ignition under either moisture regime.
    • Seasonal Movements and Home Ranges of Feral Horse Bands in Wyoming's Red Desert

      Miller, R. (Society for Range Management, 1983-03-01)
      Feral horses have seasonal movement patterns which correspond to their use of water sources and areas near ridges. Home ranges of horse bands varied in size from 73 to 303 km2. Some bands shared use of a common home range. Those bands having a common range followed similar movement patterns within their home ranges. A herd is defined as a structured social unit made up of bands following movement patterns within a common home range.
    • Relationship Between Carbohydrate, Nitrogen Contents, and Regrowth of Tall Fescue Tillers

      Bahrani, J.; Beaty, E. R.; Tan, K. H. (Society for Range Management, 1983-03-01)
      Nitrogen and water-soluble carbohydrate contents of Kentucky 31 tall fescue (Festuca arundinaceae Schreb) tillers were determined on a regrowth following clipping to a 2.5-cm stubble. There was a sharp decline in water-soluble carbohydrates of tillers as a result of clipping and N fertilization. Dry matter N content increased during the same time. The reduced carbohydrate content for clipped tillers lasted for some 10 days following clipping. After the initial decrease, water-soluble carbohydrate content in tillers increased for the next 80 days. The negative correlation between tiller N and carbonydrate content suggested that initial tiller regrowth was obtained partially from carbohydrate reserves in addition to current photosynthate production. N application immediately following clipping is at a time of low carbohydrate content and could well cause stand reduction.
    • Reducing seed dormancy in Indian ricegrass [Oryzopsis hymenoides]

      Zemetra, R. S.; Havstad, C.; Cuany, R. L. (Society for Range Management, 1983-03-01)
      Indian ricegrass [Oryzopsis hymenoides (Roem. and Schult.) Ricker] is an excellent native species for revegetation of coal and oil shale sites. However, inadequate germination due to a high seed dormancy results in poor stand development and limits its use. This paper presents the results of a series of experiments attempting to reduce the dormancy by weakening the lemma and palea by scarification of the seed covering. Four treatments (three mechanical and one concentrated sulfuric acid) were examined, alone and in combination with gibberellic acid. Three ages of seed were tested in the greenhouse, the laboratory and the field. Concentrated sulfuric acid and a modified commercial scarifier most effectively increased germination in the greenhouse; gibberellic acid enhanced germination of the younger, fresher seeds in this environment. A rubbing machine improved emergence in the field more than the other treatments. It was, however, only a modest improvement. Concentrated sulfuric acid decreased field emergence for all 3 ages of seed. Germination studies in the laboratory indicated that none of the treatments increased mortality.
    • Principles of Intensive Range Improvements

      Herbel, C. H. (Society for Range Management, 1983-03-01)
      Our expanding population is demanding more productivity and other contributions from our rangelands. Range science is concerned with the plants, animals, soils, and waters on rangelands, particularly the interaction of these factors. Native plant communities should only be used as guides to determine site potential. Extensive practices on rangelands include manipulation of animals and burning. Intensive practices include control of unwanted plants, revegetation, and fertilization. When properly conducted, intensive manipulation practices often result in much higher production than before treatment. Each land manager determines the desired level of productivity based on economic, cultural, political, and social factors, and the availability of technology. The most effective method for control of unwanted plants varies with the sites, the species, and the degree of infestation. Revegetation may be required where desirable vegetation has been depleted by past grazing abuses, droughts, and encroachment of unwanted plants. Water is generally the primary factor limiting plant growth but when that need has been satisfied, additional plant nutrients such as nitrogen and phosphorus may be useful. The more costly practices are riskier and require higher management inputs, but the potential benefits are great. With changing technology or favorable economic conditions, the range manager may decide to intensify his range improvement efforts.
    • President's Address

      Bohning, John W. (Society for Range Management, 1983-03-01)
    • Prescribed Burning in the Northern Great Plains: Yield and Cover Responses of 3 Forage Species in the Mixed Grass Prairie

      White, R. S.; Currie, P. O. (Society for Range Management, 1983-03-01)
      Prescribed burning was conducted in the fall and spring to evaluate the effects of fire on productivity of 3 forage species. Yield measurements were obtained throughout the growing season at biweekly intervals on western wheatgrass, blue grama, and threadleaf sedge. Supplementary measurements were made on vegetation cover and soil moisture. Herbage yield depended upon individual species, sampling date, and treatment. Spring burning of western wheatgrass and blue grama stimulated production by mid- and late-June, whereas fall burning also stimulated productivity but to a lesser degree. Production of threadleaf sedge was relatively unaffected by spring burning and reduced by fall burning. Fire can be used as a management practice to increase forage yield in the Northern Great Plains, but timing of utilization by livestock must receive careful consideration to assure maximum benefit.
    • Population Dynamics and Age Relationships of 8 Tree Species in Navajo National Monument, Arizona

      Brotherson, J. D.; Rushforth, S. R.; Evenson, W. E.; Johansen, J. R.; Morden, C. (Society for Range Management, 1983-03-01)
    • Nutritive Value and Intake of Kleberg Bluestem by Beef Cattle

      Pacheco, M. E.; Brown, R. D.; Bingham, R. L. (Society for Range Management, 1983-03-01)
      Four cuttings of Kleberg bluestem (Dicanthium annulatum) were fed to 15 Santa Gertrudis steers to develop prediction equations for intake based on nutrient analyses of the forage with 4 replications. The 4 forages were found to differ in nutrient content (P<.05) and intake (P<.005). DE and DMD of Kleberg bluestem can be accurately predicted by laboratory means; however, prediction of intake of this forage with present analysis is impractical.
    • Nutritional Value of Crested Wheatgrass for Wintering Mule Deer

      Urness, P. J.; Austin, D. D.; Fierro, L. C. (Society for Range Management, 1983-03-01)
      The nutritional value of crested wheatgrass in the fall to spring diet of mule deer was determined from in vivo and in vitro digestibilities, a field grazing trial, and crude protein analyses. Its dietary significance was evaluated by comparing the known diet with and without the grass component. Findings indicated fall regrowth and spring growth of crested wheatgrass favorably affected the nutritional plane of mule deer on winter range dominated by big sagebrush having intermingled seedings of this exotic grass.
    • Multivariate Statistical Methods to Determine Changes in Botanical Composition Vegetation

      Stroup, W. W.; Stubbendieck, J. (Society for Range Management, 1983-03-01)
      Confusion exists over the proper statistical methodology to use in analyzing the effect of treatments on changes in botanical composition over time. A rationale for using multivariate statistics is presented. Basic considerations involved in the use and interpretation of multivariate statistics specifically appropriate to the botanical composition problem are given. An example of how such an analysis can be performed using a common statistical computing package (SAS) is demonstrated.
    • Mitigation of Chaining Impacts to Archaeological Sites

      Haase, W. R. (Society for Range Management, 1983-03-01)
      Current strategies for protecting archaeological sites during implementation of brush management practices such as chaining are frequently inadequate. Potentially significant prehistoric remains are sometimes dealt with in a fashion conducive to their destruction. This conflict can be alleviated by developing a chaining program in which there is planned avoidance of cultural resources. This is accomplished through an intensive archaeological, soil, range, and visual assessment of project areas prior to chaining. The development of a chaining design by an interdisciplinary planning team and the "buffering" of sites during implementation of the range improvement can enhance all resources. Through careful planning, secondary impacts such as vandalism to prehistoric sites can be reduced as well.
    • Microclimate Modification of Tall Moist Grasslands of Natal by Spring Burning

      Savage, M. J.; Vermeulen, K. (Society for Range Management, 1983-03-01)
      The purpose of this study was to investigate modifying microclimatic effects of spring burning in tall grassland, long-term burning trials at Ukulinga, Pietermaritzburg, South Africa. Soil temperature (at 50 mm), soil heat, net radiation and surface reflection coefficient were monitored on various cloudless days before and after burning. Four days after burning there was no significant increase in soil temperature but soil heat and net radiation increases and surface reflection coefficient decreases (from 15% to nearly 3% at local noon) were evident. Between burning date and first day of measurements, a rainfall of less than 2 mm occurred causing greater evaporation at the burnt site (due to greater net radiation) and hence lower soil temperatures, compared to the control site. Burning also resulted in an increase in sensible plus latent plus photosynthetic heat densities (from a daily total density of 9.0 MJ m-2 before to 9.9 MJ m-2 after burning) with soil heat density increasing by 50%. Four weeks after, soil temperature and soil heat were greater for the burnt site compared to the control, but net radiation and surface reflection coefficient were not significantly different between the two sites. The appearance of green material some short time after burning is therefore probably a result of more favourable soil-plant water and surface energy relations.