• Toxicological investigations on Ruby Valley pointvetch

      Williams, M. C.; Molyneux, R. J. (Society for Range Management, 1988-09-01)
      Ruby Valley pointvetch (Oxytropis riparia Litv.), a native of the central Soviet Union, was inadvertently introduced into the United States during the early part of the 20th century. Ruby Valley pointvetch has long been established in southwestern Montana, is spreading into Wyoming and Idaho, and is being investigated for its potential as a forage plant. The plant was analyzed for aliphatic nitro compounds, soluble oxalates, nitrates, cyanide, and swainsonine. Swainsonine is found in 2 native Oxytropis species and causes the loco syndrome and congestive heart failure. The plant was tested for toxicity to 1-week-old chicks. Ruby Valley milkvetch tested negative for aliphatic nitro compounds, soluble oxalates, cyanide, and swainsonine. Nitrates were present at nontoxic levels. Leaves, stems, seeds, and pods were nontoxic when fed to chicks for 5 days at 1% of body weight as dried plant. Extracts of these plant parts fed in one dose at 10% of body weight (as dried plant) were likewise nontoxic.
    • Viewpoint: Who are those Smiths?

      Beetle, Alan A. (Society for Range Management, 1988-09-01)
    • Use of UV absorption for identifying subspecies of Artemisia tridentata

      Spomer, G. G.; Henderson, D. M. (Society for Range Management, 1988-09-01)
      Use of UV absorption spectra for identifying subspecies of Artemisia tridentata Nutt. was investigated by analyzing the relative optical densities of alcohol extracts from herbarium and fresh plant material at 240 nm, 250 nm, and 265 nm. In all but 1 comparison, mean relative optical densities were significantly different (p=0.95) between subspecies, but intraplant and intrasubspecies variation and overlap was found to be too large to permit use of UV absorbance alone for identifying individual specimens. These results held whether dry or fresh leaves were extracted, or whether methanol or ethanol was used as the extracting solvent.
    • Writing for your audience

      Young, James A. (Society for Range Management, 1988-09-01)
    • Writing for the reader

      Hart, Richard H. (Society for Range Management, 1988-09-01)
    • The use of comparative yield and dry-weight-rank techniques for monitoring arid rangeland

      Friedel, M. H.; Chewings, V. H.; Bastin, G. N. (Society for Range Management, 1988-09-01)
      The comparative yield (CY) method for estimating pasture dry weight and the dry-weight-rank (DWR) method for determining species composition were applied in a variety of arid vegetation types by several operators. The methods were evaluated for their suitability in a range monitoring program, on the basis of consistency of estimates and the time taken. Four calibration regressions for the CY technique were compared initially and, of these, linear regression of untransformed data is recommended. Differences among operators' yield estimates were unacceptably large, and the procedure of standard selection and calibration was too slow. We suggest that photographic standards can reduce the time taken and improve precision. The DWR technique was recommended because operators achieved consistent estimates of species composition within 80 minutes, which we regarded as a reasonable time for a monitoring procedure. Weighted multipliers did not improve composition estimates. The technique was easy to use but initial training of operators was important. While fixed quadrats would probably reduce differences caused by spatial variability, time spent relocating quadrats could be excessive.