• Seasonal Nitrogen Translocation in Big Bluestem During Drought Conditions

      Hayes, D. C. (Society for Range Management, 1985-09-01)
      This study, conducted during a severe drought in 1980, assesses the effects of burned and unburned treatments in tallgrass prairie on nitrogen content of big bluestem, Andropogon gerardii Vitman. Seasonal total nitrogen and amino-nitrogen translocations in big bluestem in the tallgrass prairie were studied on burned and unburned treatments within Konza Prairie Research Natural Area, Manhattan, Kans. Leaf total nitrogen dropped from .71% in June 1980 to .21% in November with no significant difference between treatments. Rhizome total nitrogen was significantly different between treatments with a June to November increase of .46% to .86% in unburned and .41% to .82% in burned treatments. Roots averaged 72% of rhizome total nitrogen, indicating that roots are also used as storage organs for nitrogen. Comparisons with other studies conducted in 1980 and 1971-1972 indicate that drought stress may reduce the total nitrogen content of big bluestem. In April 1980, emerging leaves on the unburned plots were significantly higher in amino acid concentration than those on the burned plots. Although leaf amino acid concentration was constant after July, the percent of total nitrogen as amino acids increased 3 to 4 fold from mid-August to October. Rhizome amino acid concentration was significantly higher on the unburned than on burned plots. The September 1980 increase in leaf amino acid concentration and percent of total nitrogen as amino acids indicates a breakdown of protein in aboveground tissue. The concurrent increase in rhizome amino acid concentration and percent of total nitrogen as amino acids supports the concept of fall translocation of nitrogen to the belowground parts which serve as storage organs.
    • Seed Predation, Seedling Emergence, and Rhizome Characteristics of American Licorice

      Boe, A.; Wynia, R. (Society for Range Management, 1985-09-01)
      American licorice (Glycyrrhiza lepidota Pursh) is a widespread native legume that may have potential forage or soil conservation uses. Seed predation, seedling emergence, and rhizome production were studied in 41 populations of G. lepidota from North and South Dakota. Seed predation by the beetle Acanthoscelides fraterculus (Horn) reduced viable seed production by 7 to 71%. Seedling emergence in the greenhouse and stand establishment in the field varied considerably among populations. Overall mean field emergence was 41%. Five South Dakota populations exhibited lethal chlorophyll deficient seedlings. Rhizome numbers of year-old spaced-plants ranged from 3 to 32, with a mean of 13.3. Mean number of nodes/rhizome was 7.5. This study indicated that stands of G. lepidota could be established from seed and individual plants could spread rapidly by rhizomes. However, heavy seed predation by bruchid beetles and lack of inflorescence production in cultivated nurseries could seriously limit viable seed production.
    • Sheep Losses to Predators on a California Range, 1973-1983

      Scrivner, J. H.; Howard, W. E.; Murphy, A. H.; Hays, J. R. (Society for Range Management, 1985-09-01)
      Predation at the University of California Hopland Field Station was evaluated for an 11-year period beginning in 1973. Of those lambs placed on range, an average of 2.7% were killed each year by predators. An average of 1.5% of the ewes were killed. When the number of missing animals which were killed was estimated, the average annual predation rate for lambs and ewes killed was 10.4 and 3.8%, respectively. For all known ewe and lamb deaths, respectively, 45% and 26% were caused by predators, 14% and 28% died from causes other than predation, and 41% and 46% died from unknown causes. Of those sheep killed by predators, 89% were killed by coyotes (Canis latrans), 8% by dogs, and 1% each by black bear (Ursus americanus), mountain lion (Felis concolor), and golden eagle (Aquila chrysaetos). More sheep were killed by coyotes from October to March than from April to September and the annual number of sheep killed by coyotes and dogs has increased since the beginning of the study. Not including the value of missing animals which were killed, the present value of livestock killed by predators was estimated to be $62,364.
    • Site Variation in Forage Qualities of Mountain Mahogany and Serviceberry

      Kufeld, R. C.; Stevens, M. L.; Bowden, D. C. (Society for Range Management, 1985-09-01)
      Nutrient and fiber content and in vitro digestible dry matter (IVDDM) were measured in mountain mahogany (Cercocarpus montanus) and serviceberry (Amelanchier alnifolia) samples collected during January from 8 geographic areas distributed throughout the western half of Colorado. Coefficients of variation (CV) in dry matter content, cell content, crude protein, soluble carbohydrate, cell walls, holocellulose and IVDDM were 10% or less for both species. Winter variation in these parameters appears to be small enough to permit using a constant value for them in calculating winter nutritional status of big game rangelands.
    • Technical Notes: Cannula Adaptations for Esophageally Fistulated Cattle

      Forwood, J. R.; Ortbals, J. L.; Zinn, G.; Paterson, J. A. (Society for Range Management, 1985-09-01)
      A modified, flexible pastisol reentrant ileal (MPI) cannula was made and tested for ability to eliminate esophageal depressions, to promote healing in fistulated steers already experiencing esophageal depressions and for general use in grazing situations. Aluminum and stainless steel 'sleeve-type' removable esophageal cannulas were coated with plastisol to reduce irritation of recently established and older esophageal fistulas. Both methods appear to reduce health problems in esophageally fistulated cattle used in grazing situations. However, lower cost of the MPI, health advantages and reduced labor requirements made it the cannula of choice over the sleeve-type cannulas.
    • The Influence of Several Range Improvements on Estimated Carrying Capacity and Potential Beef Production

      Svejcar, T.; Vavra, M. (Society for Range Management, 1985-09-01)
      A simple calculation is proposed for estimating carrying capacity of range sites based on seasonal forage quality and standing crop. The model estimates animal unit days a pasture can support. Potential beef production of a particular site was estimated by multiplying animal unit days by average daily gain as indicated from forage quality. Improved and unimproved portions of 4 plant communities (grassland, mixed conifer, lodgepole pine, and moist meadow) were compared for carrying capacity and potential beef production. Improvement generally resulted in large increases in both carrying capacity and potential beef production; however, only in the case of the grassland did range improvement extend the period during which weight gains could be expected. Calculations indicate that energy generally became limiting before crude protein. Forage quality was insufficient to maintain weight gains of growing animals after mid-summer. Advantages and limitations of the calculations are discussed.
    • Use of Power Curves to Monitor Range Trend

      Tanke, W. C.; Bonham, C. D. (Society for Range Management, 1985-09-01)
      Type I and Type II errors and the power of the test when testing the null hypothesis of static range trend are discussed. The consequences associated with Type I and Type II errors are judged to be similar and therefore the probability of committing a Type I or Type II error should be equal. As an example, the current range trend monitoring program for the Moose Camp Allotment on USDA Forest Service land in southwestern Montana is capable of detecting a change in range condition of one condition class 83% of the time when the probability of Type I error is set at .17 (Prob[-Type I Error] = Prob [Type II Error] = .17). Doubling the sample size would increase the ability to detect a condition class change to 95% when the probability of Type I error is set at .05 (Prob[Type I Error] = Prob[Type II Error] = .05).
    • Video Imagery: A New Remote Sensing Tool for Range Management

      Everitt, J. H.; Nixon, P. R. (Society for Range Management, 1985-09-01)
      A multi-video system that provides immediately useful narrowband black-and-white imagery within the visible to near-infrared light (0.40- to 1.10-micrometer waveband) region of the electromagnetic spectrum was evaluated as a remote sensing tool to assess several ecological rangeland ground conditions in southern Texas. The system provided imagery to detect many variables including: the presence of weeds, heavy grazing, fertilized grassland, burned areas, and gopher and ant mounds. Certain narrowband filters provided better discrimination among vegetation than others. For example, a red narrowband filter provided the best imagery to distinguish between fertilized and nonfertilized bermudagrass [Cynodon dactylon (L.) Pers.]. These results demonstrated that narrowband multi-video imagery could assist in assessing some ecological ground conditions of rangelands.
    • Viewpoint: Forage and Range Research Needs in the Central Great Plains

      Vogel, K. P.; Gorz, H. J.; Haskins, F. A. (Society for Range Management, 1985-09-01)
      In the central Great Plains, pastures and rangelands often are not economically competitive with grain crops. This has led to increases in acreages of row crops at the expense of rangelands, pastures, and hay crops on marginal lands resulting in severe erosion problems. The productivity of forages, pastures, and rangelands needs to be increased to levels that would make them economically competitive with grain crops. Innovative research will be needed to develop the required knowledge and technology upon which productivity increases can be based. Pastures and rangelands in this area are usually components of production systems which may also include the feeding of hay, silage, crop residues, and other feeds. Coordinated research teams need to be formed that can focus on all components of these production systems. Research needs and objectives of these research teams can be categorized by the land capability classes of the three major ecological regions in this area, the tall-grass, mid-grass, and short-grass prairie. In all of these regions, a classification system that is production-oriented rather than climax-oriented is needed for both pastures and rangelands if effective control of soil erosion and optimal income per land unit are to be achieved. Interstate cooperation in establishing a research team for major ecological region would facilitate the most efficient use of research resources.