• A Behavioral Study of Angora Goats on West Texas Range

      Askins, G. D.; Turner, E. E. (Society for Range Management, 1972-03-01)
      Behavior of four Angora goats was studied in sixteen observation periods for four seasons on a west Texas range. The goats consistently fed during two definite daylight feeding periods: (a) early morning, and (b) late afternoon to dusk. Bedding generally occurred whenever darkness became evident and little or no feeding activity was observed between that time and daybreak. The four goats differed somewhat in their behavioral activities, but were remarkably similar in their vegetation preference. Seasonal difference seemed to have an important effect upon both vegetative preference and behavioral activities./Cuatro cabras fueron marcadas y sus actividades fueron observadas a través del año. Las cabras mostraron un patrón de actividades sistemático a través del año. Empezaron el día levantándose y rumiando por un tiempo breve, seguido por una época de pastoreo de tres horas, luego por 30 minutos de descanso y después pastoreo otra vez hasta mediodía. Tomaron agua y descansaron en la sombra durante medio día hasta tres horas antes de la puesta del sol. Comieron otra vez por tres horas o sea hasta en la noche cuando tomaron agua otra vez y comieron sal, seguido por descanso por toda la noche. Aproximadamente de 34.4% de su tiempo de pastoreo fué con gramíneas y 65.6% fué ramoneo. Parece ser que las estaciones del año tienen un importante efecto en la preferencia del forraje pastoreado, y las actividades de las cabras.
    • A Beta Test Comparison Between the New Packard 2260 XL and the LKB Quantulus and 1219 SM: Low-Level Radiocarbon and Tritium Determinations

      Kalin, Robert M. (Department of Geosciences, The University of Arizona, 1989-01-01)
      A Packard 2260 XL liquid scintillation counter was placed in an underground counting chamber to test performance under immense physical shielding. Results from the Packard 2260 XL are compared with two other counters under the same conditions, the LKB Quantulus, which has operated for two years in this laboratory, and the LKB 1219 SM, in use since January 1988.
    • A Beta-Counting System Linked to a Personal Computer

      Omoto, Kunio (Department of Geosciences, The University of Arizona, 1995-01-01)
      The automatic beta-counting system plays a significant role in obtaining high-level reproducibility and reliability in conventional radiocarbon dating. I review here the results achieved by using the "Fully Automatic Radiocarbon Dating System" developed by Omoto (1982). Since setting up the system in 1981, I was able not only to save operator time in beta counting, but also to obtain accurate dates with only minimal uncertainties. Another positive result was the introduction of the automatic voltage correction program, which produced excellent results for counting sample materials over a long period.
    • A Bibliography of Radiocarbon Dating

      Johnson, Frederick (American Journal of Science, 1959-01-01)
    • A Bibliometric Analysis of Worldwide Publications on Scrub

      Botello, Ana; Cabezas, José; Pulgarin, Antonio; Escudero, José C. (Society for Range Management, 1998-04-01)
    • A Book’s Impact on a Rural Village in Nepal

      Lauritzen, Carol; Eastern Oregon University; Oregon Reading Association (Worlds of Words: Center for Global Literacies and Literatures (University of Arizona), 2018)
    • A Brief History of How the Society for Range Management was Founded

      Howery, Larry D. (Society for Range Management, 2015-12-01)
      On the Ground • About eight decades ago, The Society for Range Managements founders began to shape and refine their collective vision to create a science-based professional society that would serve as a platform for learning and collaboration on all aspects of rangeland management. • The inaugural meeting in 1948 led to the founding of the American Society of Range Management (ASRM), a new journal dedicated to range science and management (The Journal of Range Management), an initial ASRM committee structure, and decentralization of ASRM through the formation of local sections. • ASRM (now known as The Society for Range Management or SRM) has achieved many milestones and accomplishments since its founding. Although todays issues are different and morecomplex than in 1948, the basic leadership principles espoused by the founders provide a template for addressing the challenges that the rangeland profession faces in the 21st century.
    • A Brief History of Range Management in the United States

      Holechek, Jerry L. (Society for Range Management, 1981-02-01)
    • A Capacitance Meter for Estimating Forage Weight

      Fletcher, J. E.; Robinson, M. E. (Society for Range Management, 1956-03-01)
    • A Case Study Evaluating Economic Implications of Two Grazing Strategies for Cattle Ranches in Northwest Argentina

      Quiroga, R. Emiliano; Blanco, Lisandro J.; Ferrando, Carlos A. (Society for Range Management, 2009-09-01)
      In the Argentinean Chaco Arido region, cattle production based on cow-calf operations is the principal source of agricultural income, and rangeland is the main forage source for cattle. Traditional grazing strategy (TGS, high stocking rate and continuous grazing) is considered the main cause of current rangeland degradation. Research shows that rangeland and cattle production improvements are possible when using a conservative grazing strategy (CGS, moderate stocking rate and rest rotation grazing). The aim of this research was to compare the effects of TGS and CGS applications on economic results for a cattle ranch in the region. To achieve this objective we used an approach that included estimations of forage and cattle production, and economic results. The study period was 1972/73–1983/84. Results showed that during the study period forage production and herd size were almost doubled with CGS, but maintained with TGS. The difference in net income between CGS and TGS (in Argentinean pesos, ), increased linearly from negative (–2.88 ha-1) to positive (4.48 ha-1) in the first 4 yr, and then was maintained at positive values (averaging 4.48 ha-1). Data suggest that CGS leads to higher productivity and better economic results than TGS in the medium and long terms. 
    • A Case Study for Optimal Allocation of Range Resources

      D'Aquino, S. A. (Society for Range Management, 1974-05-01)
      A linear programming model was developed to help in the management of range resource systems. This analysis simultaneously considers per acre management costs and resulting per animal gross revenues. The management plan sets out a season-by-season use of land areas and associated forage resources with the objective of maximizing net dollar returns. Procedures developed in this study may also be applied to public resource management problems.
    • A Case Study in Woodland Restoration

      Boettcher, Susan E.; Johnson, W. Carter; Gartner, F. Robert (Society for Range Management, 1995-02-01)
    • A case study of impact-induced hydrothermal activity: The Haughton impact structure, Devon Island, Canadian High Arctic

      Osinski, Gordon R.; Lee, Pascal; Parnell, John; Spray, John G.; Baron, Martin (The Meteoritical Society, 2005-01-01)
      The well-preserved state and excellent exposure at the 39 Ma Haughton impact structure, 23 km in diameter, allows a clearer picture to be made of the nature and distribution of hydrothermal deposits within mid-size complex impact craters. A moderate- to low-temperature hydrothermal system was generated at Haughton by the interaction of groundwaters with the hot impact melt breccias that filled the interior of the crater. Four distinct settings and styles of hydrothermal mineralization are recognized at Haughton: a) vugs and veins within the impact melt breccias, with an increase in intensity of alteration towards the base; b) cementation of brecciated lithologies in the interior of the central uplift; degrees C) intense veining around the heavily faulted and fractured outer margin of the central uplift; and d) hydrothermal pipe structures or gossans and mineralization along fault surfaces around the faulted crater rim. Each setting is associated with a different suite of hydrothermal minerals that were deposited at different stages in the development of the hydrothermal system. Minor, early quartz precipitation in the impact melt breccias was followed by the deposition of calcite and marcasite within cavities and fractures, plus minor celestite, barite, and fluorite. This occurred at temperatures of at least 200 degrees C and down to ~100-120 degrees C. Hydrothermal circulation through the faulted crater rim with the deposition of calcite, quartz, marcasite, and pyrite, occurred at similar temperatures. Quartz mineralization within breccias of the interior of the central uplift occurred in two distinct episodes (~250 down to ~90 degrees C, and <60 degrees C). With continued cooling (<90 degrees C), calcite and quartz were precipitated in vugs and veins within the impact melt breccias. Calcite veining around the outer margin of the central uplift occurred at temperatures of ~150 degrees C down to <60 degrees C. Mobilization of hydrocarbons from the country rocks occurred during formation of the higher temperature calcite veins (>80 degrees C). Appreciation of the structural features of impact craters has proven to be key to understanding the distribution of hydrothermal deposits at Haughton.
    • A Century of Managing Rangelands on National Forests: Or It Ain’t Easy Being a Range Con in the New West

      Reed, Floyd; Bradford, David; McConkey, Justin (Society for Range Management, 2005-06-01)
    • A Century of Rangeland Conservation in the Forest Service

      Bosworth, Dale (Society for Range Management, 2005-06-01)
    • A Challenge to Stockmen and Range Officials

      Savage, D. A. (Society for Range Management, 1951-05-01)
    • A chamber design for measuring net CO2 exchange on rangeland

      Angell, R.; Svejcar, T. (Society for Range Management, 1999-01-01)
      Net carbon exchange of terrestrial ecosystems will likely change as atmospheric CO2 concentration increases. Currently, little is known of the annual dynamics or magnitude of CO2 flux on many native and agricultural ecosystems. Remoteness of many ecosystems has limited our ability to measure CO2 flux on undisturbed vegetation. Today, many plant ecologists have portable photosynthesis systems with which they make single-leaf photosynthesis measurements. Utility of this equipment is enhanced when canopy-level CO2 flux is also measured. We designed a portable 1-m3 closed chamber for use in measuring CO2 exchange in short statured vegetation with widely varied canopy structure. The design includes external ductwork equipped with doors which are used to open the chamber for ventilation with outside air between measurements. The chamber was tested on a Wyoming big sagebrush (Artemisia tridentata ssp. Wyomingensis Nutt.)/Thurber's needlegrass (Stipa thurberiana Piper) community using 10 plots equally divided between shrub and interspace. The ductwork and doors provided adequate ventilation to allow consecutive measurements of CO2 flux without removing the chamber from the plot. The chamber could differentiate CO2 flux between plots with sagebrush and those with grass only, even at relatively low fluxes. Net CO2 uptake per unit ground area was greater (P = 0.04) on sagebrush-grass plots (7.6 +/- 1.4 micromoles m-2 s-1) than on interspace plots without sagebrush (3.1 +/- 1.0 micromole m-2 s-1). Chamber and leaf temperature increased by an average of 0.5 and 1.2 degrees C, respectively, during measurements.
    • A chemical sequence of macromolecular organic matter in the CM chondrites

      Naraoka, H.; Mita, H.; Komiya, M.; Yoneda, S.; Kojima, H.; Shimoyama, A. (The Meteoritical Society, 2004-01-01)
      A new organic parameter is proposed to show a chemical sequence of organic matter in carbonaceous chondrites, using carbon, hydrogen, and nitrogen concentrations of solvent-insoluble and high-molecular weight organic matter (macromolecules) and the molecular abundance of solvent-extractable organic compounds. The H/C atomic ratio of the macromolecule purified from nine CM chondrites including the Murchison, Sayama, and seven Antarctic meteorites varies widely from 0.11 to 0.72. During the H/C change of ~0.7 to ~0.3, the N/C atomic ratio remains at ~0.04, followed by a sharp decline from ~0.040 to ~0.017 between H/C ratios from ~0.3 to ~0.1. The H/CN/ degrees C sequence shows different degrees of organic matter thermal alteration among these chondrites in which the smaller H/C-N/C value implies higher alteration levels on the meteorite parent body. In addition, solvent-extractable organic compounds such as amino acids, carboxylic acids, and polycyclic aromatic hydrocarbons are abundant only in chondrites with macromolecular H/C values >~0.5. These organic compounds were extremely depleted in the chondrites with a macromolecular H/C value of <~0.5. Possibly, most solvent-extractable organic compounds could have been lost during the thermal alteration event that caused the H/C ratio of the macromolecule to fall below 0.4.