• A Note on Single-Year Calibration of the Radiocarbon Time Scale, AD 1510-1954

      Stuiver, Minze (Department of Geosciences, The University of Arizona, 1993-01-01)
    • An Economic Analysis of Two Systems and Three Levels of Grazing on Ponderosa Pine -Bunchgrass Range

      Quigley, T. M.; Skovlin, J. M.; Workman, J. P. (Society for Range Management, 1984-07-01)
      A long-term study of the effects of season-long and deferred rotation grazing at different stocking rates examined cow and calf weight gains. Production functions were derived using stocking rate (AUM's/ha) as a variable input and average summer weight gain (kg/ha) as the output. These functions were optimized economically to determine profit maximizing stocking rates. Optimum stocking rates for season-long grazing on ponderosa pine-bunchgrass range were found to be moderate or light over a wide range of feasible price ratios. Optimum stocking rates for deferred rotation grazing did not exceed a moderate level at any feasible price ratio. The ratio of forage price ($/AUM) to the price of livestock ($/kg) must exceed 11 under deferred rotation grazing and 18 under season-long grazing before light stocking becomes the optimum. Based on fall 1979 livestock and forage prices, the stocking rate for profit maximization was moderate (.235 AUM/ha or 10.6 acres/AUM) for deferred rotation and moderate (.312 AUM/ha or 7.9 acres/AUM) for season-long. Season-long grazing also produced a higher net return than did deferred rotation. To remain at the profit maximizing stocking rate while shifting from season-long to deferred rotation, a manager would have to reduce the stocking level at all price ratios.
    • Anagyrine in Western American Lupines

      Davis, A. M.; Stout, D. M. (Society for Range Management, 1986-01-01)
      The teratogenic condition known as 'crooked calf disease' occurs when pregnant cows eat certain lupines with anagyrine concentrations at or above 1.44 g kg-1 dry matter between the 40th and 70th day of pregnancy. Five of eight species collected in Oregon and Washington had accessions with anagyrine at or above the hazardous concentrations as determined by gas/liquid chromatography. A total of 14 species of lupine are now shown to contain accessions with potentially hazardous concentrations of anagyrine. Any range/livestock management system that will expose susceptible cattle to anagyrine-bearing lupines could result in serious calf crop losses.
    • Annual Fluctuation in Production of Some Eastern Oregon and Washington Shrubs

      Garrison, G. A. (Society for Range Management, 1953-03-01)
    • Anomalous 11-Year Delta-14C Cycle at High Latitudes?

      Damon, Paul E.; Burr, George; Cain, W. J.; Donahue, D. J. (Department of Geosciences, The University of Arizona, 1992-01-01)
      We find no evidence for an anomalously intense 11-yr cycle in Delta-14C at high latitudes during the period, AD 1870–1885, as reported by Fan et al. (1983, 1986). However, there does appear to be a regional effect within the MacKenzie River region (67 degrees N, 130 degrees W), with atmospheric 14C depressed by 2.6 +/0.9 (mean of sigma) % relative to the Olympic Peninsula. Such an effect would require only 5% of CO2 in the air mass to have been derived from 5% 14C-depleted soil gas CO2. This small but apparently significant regional effect could be caused by accumulation of CO2 within the frozen earth followed by outgassing during the spring thaw. The short growing season would enhance the effect by allowing insufficient time for global atmospheric equilibration.
    • Anthropogenic Changes in Organic Carbon and Trace Metal Input to Lake Washington

      Schell, W. R.; Swanson, J. R.; Currie, L. A. (American Journal of Science, 1983-01-01)
      An example of how man's contaminants are introduced, deposited, and retained in sediments giving a chronological record of events has been developed for Lake Washington, Seattle. Significant amounts of both inorganic and organic compounds in the environment originate from fossil fuel sources, such as power plants and motor vehicles. Many organic compounds are introduced also from contemporary biogenic materials. Through the combined carbon isotope analysis technique (CCIA), we can distinguish between fossil and contemporary carbon sources classes (using 14C), as well as sources within each class (using 13C). To establish the chronology of the organic carbon pollutant input to the lake sediment, the ages of the layers were determined using 210pb dating techniques. Sediment profiles of trace metals and a fallout radionuclide plutonium were also obtained and compared with the carbon isotope profiles. The results show that the total organic carbon (TOC) concentration correspond to 93% modern carbon before 1905. This 14C concentration in TOC decreased to ∼60% modern in the 1930's and now is between 95 and 80% modern. The lipid fraction is ca 30% modern and the total aromatic hydrocarbon fraction reached a minimum of 5% modern in 1954. The large decrease in 14C of TOC around 1930 is believed to be due to coal dust or fly ash. The trace metal concentration also increased substantially at this time. The pattern observed in the sediment thus reflects the change in the local energy consumption pattern from a predominately coal to an oil-based economy. From the plutonium profile we infer that mixing occurs for 3 or 4 years before the sediment layers are compacted.
    • Can Fertilizers Effectively Increase Our Range Land Production?

      Patterson, J. K.; Youngman, V. E. (Society for Range Management, 1960-09-01)
    • Control of Dalmatian Toadflax

      Robocker, W. C. (Society for Range Management, 1968-03-01)
      Trials of several chemicals over a 6-year period showed that phenoxypropionic herbicides were superior to phenoxyacetic herbicides in controlling Dalmatian toadflax. Satisfactory control was obtained with silvex at a minimum rate of 3 lb/acre. Rates of silvex required to significantly reduce or control the plant did no significant injury to perennial grasses. Picloram applied in granular form to the soil in the fall was more effective than a foliar application at the same rate in the spring. A combination of silvex plus picloram, 2 plus 0.5 or 2 plus 0.25 lb/acre, respectively, also controlled Dalmatian toadflax. Cultural and managerial, as well as chemical control methods may be necessary for economic and effective control of the plant.
    • Correcting for Differential Digestibility in Microhistological Analyses Involving Common Coastal Forages of the Pacific Northwest

      Leslie, D. M.; Vavra, M.; Starkey, E. E.; Slater, R. C. (Society for Range Management, 1983-11-01)
      The accuracy of microhistological techniques to describe herbivore diets can be affected by differential digestibility of ingested forages. Correction factors were developed to adjust for those effects in 17 common forages of coastal, forested ranges of the Pacific Northwest. Two ferns, a moss and a sedge were overestimated by microhistological analysis in all seasons, while most shrubs, forbs and a grass were underestimated. Trees were not consistently over- or underestimated. Phenology significantly affected the degree of over- or underestimation of most forages. Failure to correct for differential digestibility will significantly bias results of microhistological techniques such as fecal analyses.
    • Defoliation of Intermediate Wheatgrass Under Seasonal and Short-Duration Grazing

      Pierson, F. B.; Scarnecchia, D. L. (Society for Range Management, 1987-05-01)
      Defoliation of intermediate wheatgrass (Agropyron intermedium by cattle was examined under seasonal and short-duration grazing. Tiller height, number of green leaves per tiller, phenological status, and defoliation frequency were measured on individually marked tillers during 2 grazing seasons. Defoliations at high and low stocking densities (5.2 and 2.6 animal-units/ha) were examined during the 1983 growing season. At equal stocking rates, standing crop decreased more rapidly under low stocking density. Mean tiller height and mean number of leaves per tiller decreased linearly over time in both treatments. In 1984, 14 heifers were moved through 3 rotations of an 8 subunit short-duration grazing system in 72 days. A larger fraction of tiller height and a higher number of green leaves per tiller were defoliated during rotation one than during rotation three. Animals grazed the greatest number of tillers during rotation one. Biting rate varied logarithmically with the mean number of green leaves per tiller. Time spent grazing was significantly and inversely related to the mean number of green leaves per tiller. This result suggests that animals were selectively grazing green leaves over coarse stem, and spent more time searching for them as their numbers decreased.
    • Determining Equitable Grazing Fees for Washington Department of Natural Resources Land

      Harris, G. A.; Hoffman, W. R. (Society for Range Management, 1963-09-01)
    • Developing a Grazing-tolerant Native Grass for Bluebunch Wheatgrass Sites

      Jones, T. A.; Nielson, D. C.; Carlson, J. R. (Society for Range Management, 1991-06-01)
    • Diets of Steers on a Shrub-Steppe Rangeland in South-Central Washington

      Uresk, D. W.; Rickard, W. H. (Society for Range Management, 1976-11-01)
      Botanical composition of steers' diets on a shrub-steppe rangeland in south-central Washington was examined by inspection of finely ground fecal samples viewed through a microscope. Four species, Cusick bluegrass, Thurber needlegrass, hawksbeard and bluebunch wheatgrass, comprised 92% of the total diet. Grasses accounted for 73% of the diet and forbs and half shrubs contributed 26%. Botanical composition of the diets changed throughout the spring grazing season with changing availability and maturation of herbage. Preference indices in decreasing order were: Cusick bluegrass > Thurber needlegrass > hawksbeard > bluebunch wheatgrass, but bluebunch wheatgrass was the most abundant species in the pasture. The second most abundant grass, Sandberg bluegrass, was not selected by steers.
    • Diets of the Black-tailed Hare in Steppe Vegetation

      Uresk, D. W. (Society for Range Management, 1978-11-01)
      Thirteen species of plants were identified in fecal pellets of black-tailed hares collected from sagebrush and bitterbrush communities in southcentral Washington. Microscopic analysis of plant fragments indicated that yarrow was the most common food item in the diet, making up 25% of the overall diet. Other food items in decreasing order of importance were: turpentine cymopterus > hoary aster > needleandthread > and Jim Hill mustard. Preference indices indicated that needleandthread was the most preferred plant in the sagebrush community, while yarrow was the most preferred plant in the bitterbrush community. Although the communities were not similar in plant species frequency of occurrence and cover, the hare diets were quite similar in both communities, indicating that hares were actively seeking preferred foods.
    • Economics of Selected Alternative Calving Dates

      Mueller, R. G.; Harris, G. A. (Society for Range Management, 1967-03-01)
      Shifting calving dates from present early spring to fall or late spring dates offers an opportunity to increase income to range-based cattle operations in north central or north-eastern Washington. Lower death losses and better marketing opportunities more than offset higher winter feed costs. Fall calves also make more efficient use of abundant spring ranges in this region, and dry cows make more uniform use of mountain summer ranges.
    • Effect of weed seed rate and grass defoliation level on diffuse knapweed

      Sheley, R. L.; Olson, B. E.; Larson, L. L. (Society for Range Management, 1997-01-01)
      Diffuse knapweed (Centaurea diffusa Lam.), an invasive weed, has reduced forage production and biodiversity, and increased soil erosion on over a million hectares of rangeland in the western United States. This study evaluated the effects of a single grass defoliation on establishment of diffuse knapweed seeded at 2 rates into a bluebunch wheatgrass (Pseudoroegneria spicata [Pursh.] Scribn and Smith)/needle-and-thread (Stipa comata Trin. &Rupr.) community and a crested wheatgrass (Agropyron cristatum (L.) Gaertn.) community. Six defoliation levels (0, 20, 40, 60, 80, 100%) and 2 seeding rates (3,000, 6,000 diffuse knapweed seeds) were applied to 1 m2 plots in a randomized-complete-block design (n=4). Diffuse knapweed was seeded in the fall of 1992, and grasses were defoliated on 28 April 1993. The number of flowering culms and weed seedlings were counted in September 1993. Densities of diffuse knapweed seedlings, juveniles, and adults, as well as plant standing crop, were determined in May 1994. Seed rate had minimal effect on diffuse knapweed density. By May 1994, densities of diffuse knapweed were about 20 and 30 plants m-2 on undefoliated bluebunch wheatgrass and crested wheatgrass plots, respectively, indicating that defoliation is not required for this noxious weed to become established. Higher levels of grass defoliation (>60%), especially of bluebunch wheatgrass, enhanced diffuse knapweed establishment, indicating that moderate (less than or equal to 60%) defoliation would not necessarily accelerate invasion by diffuse knapweed.
    • Effects of Herbicides, Burning, and Seeding Date in Reseeding and Arid Range

      Robocker, W. C.; Gates, D. H.; Kerr, H. D. (Society for Range Management, 1965-05-01)
      In a former sagebrush-bluebunch wheatgrass site at Ephrata, Washington, neither application of herbicides nor burning for control of downy brome and Sandberg's bluegrass before planting wheatgrasses were effective in increasing stands of wheatgrass seedlings. In this area of dry summers and approximately 8 inches annual precipitation, severe climatic stresses were primarily responsible in determining the establishment or failure of seedlings.
    • Electric fences for reducing sheep losses to predators

      Nass, R. D.; Theade, J. (Society for Range Management, 1988-05-01)
      The use of anti-predator electric fences for reducing predation on sheep was investigated by interviewing 101 sheep producers in the Pacific Northwest. Significant reductions in sheep losses to predators were reported after installation of electric fences compared to pre-fence losses. Low sheep losses to predation were also reported by those producers that acquired sheep after installation of electric fences. The expenses of construction and maintenance were important considerations in management plans; however, most producers were satisfied with electric fences for sheep containment and predator exclusion.
    • Elk Use of Winter Range as Affected by Cattle Grazing, Fertilizing, and Burning in Southeastern Washington Forage Allocation

      Skovlin, J. M.; Edgerton, P. J.; McConnell, B. R. (Society for Range Management, 1983-03-01)
      A study of ways to increase winter use by elk of Pacific bunchgrass foothill range in southeastern Washington employed fertilizing and rangeland burning, with and without spring cattle grazing. First-year response of elk to fertilizer applied in fall (56 kg N/ha) was a 49% increase in use; however, no significant carry-over effect was noted in subsequent years. Fall burning to remove dead standing litter and enhance forage palatability provided no increase in elk use in winter. Intensive cattle grazing in spring to promote regrowth did not increase elk use. In fact, cattle grazing decreased winter elk use by 28% in 1 of the 3 years studied. The cost effectiveness of increasing elk use by fertilizing appeared marginal except perhaps in special situations. A discussion of forage allocation to both elk and cattle is presented.