• Bitterbrush Germination with Constant and Alternating Temperatures

      Evans, R. A.; Young, J. A. (Society for Range Management, 1977-01-01)
      The germination of bitterbrush (Purshia tridentata) seeds in relation to constant and alternating temperature regimes was investigated. The germination of untreated, stratified, and thiourea-treated seeds was compared. Germination of untreated seeds was greatest with cold (night) temperatures in the optimum range (2 degrees to 5 degrees C) for stratification. Warm (day) temperatures of 10 degrees to 40 degrees C gave relatively high germination when the night temperatures were in the stratification range. Thiourea treatment greatly expanded the number of temperature regimes that gave maximum germination. Thiourea treatment also increased the amount of germination, both in the optimum temperature range and at suboptimal or superoptimal ranges. Stratification enhanced germination of bitterbrush seeds, but the magnitude of response in relation to temperature regimes was not identical to enhancement with thiourea treatment.
    • Changing Philosophies of Rangeland Management in the United States

      Harris, G. A. (Society for Range Management, 1977-01-01)
    • Chromic Oxide as an Indicator of Total Fecal Output in White-tailed Deer

      Ruggiero, L. F.; Whelan, J. B. (Society for Range Management, 1977-01-01)
      Two captive rumen-fistulated white-tailed deer (Odocoileus virginianus) were used to evaluate chromic oxide as an external indicator of total fecal output. Acknowledging the limitation imposed by having only two rumen-fistulated animals, accurate estimates of total daily fecal output were made by combining average values obtained from sampling at different times during the day. Factors which contributed to diurnal variation in excretion of chromic oxide should be studied further before the technique can be of practical value.
    • Dry Season Regrowth of Six Forage Species Following Wildfire

      Falvey, J. L. (Society for Range Management, 1977-01-01)
      The regrowth of three introduced perennial grasses, buffelgrass, Pangolagrass, and Sabigrass; one native perennial grass, sehima; and two perennial legumes, Caribbean stylo and leucaena, after a dry season wildfire was studied in northern Australia. The native grass produced similar quantities of dry matter during the dry season but was of lower digestibility and crude protein content than all other species. Crude protein yield per hectare was highest for Sabigrass during the dry season. After the onset of the wet season the native grass produced significantly more dry matter and crude protein per hectare than all other species. Neither of the legumes provided large amounts of feed during the dry season. It is suggested that introduced grasses may be of greater value after a fire while native grasses may be superior after rains have begun.
    • Effects of Range Treatment With 2,4-D on Prairie Dog Diet

      Fagerstone, K. A.; Tietjen, H. P.; LaVoie, G. K. (Society for Range Management, 1977-01-01)
      Two established prairie dog colonies in Montana were studied to determine the effect of range treatment with 2,4-D on prairie dogs' diet. One colony was sprayed with 2,4-D for 2 consecutive years and the other was not treated. There was a significant reduction in foliar cover by forbs and shrubs on the treated colony but no change on the untreated colony. Foliar cover by grass did not change significantly on either area. Prairie dog diet changed significantly from forbs to grass after forb coverage was reduced. Before spraying, prairie dogs ate 73% forbs and 5% grass. Afterward, they ate 9% forbs and 82% grass. The availability of these foods appeared to be responsible for the diet change. Despite the change in diet, the 2,4-D treatment appeared to have little detrimental effect on prairie dogs. They remained in good condition after treatment, as indicated by body weight, and there was no significant difference in prairie dog activity between the treated and untreated colonies. There was considerable variation in diet between the two colonies the first year, with the prairie dogs preferring grass in the untreated colony and forbs in the treated colony. However, in later years preference values were higher for grass than for forbs on both colonies.
    • Effects of Rest Following Defoliations on the Recovery of Several Range Species

      Trlica, M. J.; Buwai, M.; Menke, J. W. (Society for Range Management, 1977-01-01)
      Seven range species, western wheatgrass (Agropyron smithii), blue grama (Bouteloua gracilis), fourwing saltbush (Artiplex canescens), antelope bitterbrush (Purshia tridentata), fringed sagewort (Artemisia frigida), scarlet globemallow (Sphaeralcea coccinea), and little rabbitbrush (Chrysothamnus vicidiflorus) were heavily defoliated once to remove 90% of the foliage during each of four different phenological stages. Defoliation effects were evaluated in the fall after the defoliated plants had received from 14 to 26 months of rest. Western wheatgrass, little rabbitbrush, and scarlet globemallow made good recovery in herbage yield, vigor, and total nonstructural carbohydrates (TNC) after a single heavy defoliation followed by 14 to 26 months of rest. Vigor and TNC levels of defoliated blue grama plants were similar to those of the control plants after the rest period, but the rest period was insufficient for the recovery of herbage yield. Herbage yield, vigor, and TNC levels of antelope bitterbrush and fourwing saltbush plants were still less than those of the control plants after the rest period when plants had been previously defoliated during the seed shatter or near maturity phenological stage. A 14- to 26-month rest period was insufficient for complete recovery of herbage yield, vigor, and TNC levels of fringed sagewort subjected to a single heavy defoliation at any phenological stage. After 26 months of rest, antelope bitterbrush and fourwing saltbush previously subjected to three heavy defoliations during quiescence, fruit developing, and fall regrowth showed some recovery. However, six heavy defoliations were detrimental and plants made little recovery in herbage yield, vigor, and TNC even after more than 2 years of rest. Blue grama plants that received three heavy defoliations made fair recovery after 2 years of rest. However, more than 2 years of nonuse would be necessary before blue grama plants subjected to six heavy multiple defoliations could completely recover. Scarlet globemallow subjected to either three or six heavy defoliations and then given 26 months of rest had herbage yields, vigor, and TNC levels that were fairly similar to that of the control plants.
    • Effects of Subsoil Draining on Heather Moors in Scotland

      Phillips, J.; Moss, R. (Society for Range Management, 1977-01-01)
      Subsoil draining improved the growth and nutrient content of heather on Scottish moors covered by shallow peat, where drainage is impeded by an iron pan underneath. On such moors, subsoiling has significant advantages over conventional open drains.
    • Food Relations of Wild Free-Roaming Horses to Livestock and Big Game, Red Desert, Wyoming

      Olsen, F. W.; Hansen, R. M. (Society for Range Management, 1977-01-01)
      The seasonal foods selected by wild horses, cattle, elk, domestic sheep, and antelope on the Red Desert in southwestern Wyoming were determined by microscopic inspection of fecal material. A large percentage of the diets of wild horses, cattle, and elk were the same species of grasses and sedges. Wheatgrass and needlegrass each made up 11 to 46% of the average annual diets of the herbivores studied except antelope. Sagebrush was the major food in antelope diets regardless of season. Saltbush was an important food in each herbivore's seasonal diet and was the major food of domestic sheep each season except summer. Each herbivore species ate a variety of plants each season, but the majority of the diet within a season usually consisted of fewer than six major plant species.
    • Improving Gambel Oak Ranges for Elk and Mule Deer by Spraying with 2,4,5-TP

      Kufeld, R. C. (Society for Range Management, 1977-01-01)
      Areas of Gambel oak vegetation in northwestern Colorado were sprayed with 2,4,5-TP to evaluate effects on plant abundance and deer and elk use 2 and 5 years after treatment. Grasses increased in abundance 44% after 2 years; shrubs and forbs decreased 29 and 15%, respectively. After 5 years, grasses and shrubs were 17 and 7%, respectively, above pretreatment levels of abundance; forbs were 4% below. Total vegetation on the treated area decreased 4% after 2 years, while a 5% increase was recorded after 5 years. Elk and deer use on the sprayed area increased 73 and 16%, respectively, 2 years after spraying. After 5 years elk use was 11% above pretreatment levels and deer use was 21% below. If 2,4,5-TP is used to spray Gambel oak to modify plant composition and increase elk or deer use, the area should be resprayed at 3-year intervals, indefinitely, if the improved situation is to be maintained.
    • Phytotoxic Effects of Bunchgrass Residues on Germination and Initial Root Growth of Yellow Sweetclover

      Rietveld, W. J. (Society for Range Management, 1977-01-01)
      The subclimax bunchgrasses Arizona fescue and mountain muhly promptly invade disturbances in the climax ponderosa pine forest and develop into dense, persistent, impenetrable communities. Yellow sweetclover and several weed species invade disturbances in the bunchgrass community, flourish briefly, then decline as the bunchgrasses recover the site. Extracts prepared from green foliage and straw of fescue and muhly significantly reduced sweetclover seed germination and retarded speed of elongation and mean radicle length. Leachates from live grass foliage significantly inhibited sweetclover seed germination, suggesting that leaching may be a route of release of the inhibitor.
    • Plains Pricklypear Is a Good Forage for Cattle

      Shoop, M. C.; Alford, E. J.; Mayland, H. F. (Society for Range Management, 1977-01-01)
      Singed plains pricklypear was assessed as a cattle forage. In an 84-day feeding trial, six pairs of heifers were individually fed a basal ration of hay and cottonseed meal at 2.3% of initial bodyweight. One heifer in each pair also ate singed pricklypear offered ad libitum. Pricklypear increased total dry matter consumption 43% and weight gain 72%. The heifers experienced no digestive problems during the trial or ensuing 60 days on pricklypear range. Chemical analyses and microdigestion trials indicated that digestibility of pricklypear was equal or superior to that of high quality alfalfa hay. Pricklypear contained about 40% more soluble carbohydrates than alfalfa hay, but contained only 3.4% digestible protein. Therefore, rations containing pricklypear would usually require protein supplementation. We concluded that singed pricklypear was a palatable and nutritious feed and should be evaluated as an additional forage on shortgrass range.
    • Plant Succession Following Chaining of Pinyon-Juniper Woodlands in Eastern Nevada

      Tausch, R. J.; Tueller, P. T. (Society for Range Management, 1977-01-01)
      This study was undertaken to determine some of the long-term effects of secondary succession on tree control in pinyon-juniper woodlands by cabling and chaining with "debris in place," a technique used for about two decades. Plant species representative of all the successional stages we observed following treatment exist simultaneously from treatment. These observed changes were primarily changes in relative abundance resulting from differences in the growth rates and competitive abilities of the species concerned. Competitive ability appears directly related to the length of time following treatment that a species is able to maintain an increased growth rate. The trees maintain this increased growth for two to three times as long as any understory species studied. The result is a steady reduction of understory cover and production beyond the fifth to eight year following treatment, depending on site.
    • Reseda lutea: A Multipurpose Plant for Arid and Semiarid Lands

      Moghaddam, M. R. (Society for Range Management, 1977-01-01)
      Reseda lutea is a plant well adapted to the arid and semiarid rangelands of Iran. It provides early spring green growth, is palatable to sheep and goats, and compares favorably with alfalfa in nutritive content.
    • Seasonal Use of Soil Water by Mature Velvet Mesquite

      Cable, D. R. (Society for Range Management, 1977-01-01)
      Mesquites used water consistently to a depth of 3 m and outward to 10 m beyond the crowns, but use at 15 m was limited mainly to drier periods when water supplies closer to the trees were depleted. With the start of spring growth, water was extracted most rapidly from the surface layers. As the season advanced, the watersupply zone became increasingly thicker. Rates of extraction were highest immediately after recharge in early spring and early summer, and lowest in late fall. Differences in available water in the soil accounted for 72 to 88% of the variation in rates of extraction. The competitive effect of velvet mesquite on perennial grasses is most severe in the upper 37.5 cm of soil under and near the mesquite crowns, and gradually decreases with distance into adjacent openings. The competitive effect in the openings is much more severe in dry years than in wet years.
    • Species Susceptibility to Atrazine Herbicide on Shortgrass Range

      Houston, W. R. (Society for Range Management, 1977-01-01)
      Atrazine was applied at 2 kg/ha for three consecutive years on shortgrass range in northeastern Colorado. The atrazine controlled all annual plant species, greatly reduced frequency of occurrence of cool-season perennial grasses, and increased drought survival of warm-season perennial grasses and two warm-season perennial forbs. Other species varied in their susceptibility to atrazine. The species frequency method of vegetation sampling used in this study provided reliable data for 27 of the approximately 100 species encountered on this range.
    • Squirreltail Seed Germination

      Young, J. A.; Evans, R. A. (Society for Range Management, 1977-01-01)
      Germination tests on squirreltail seed showed that three temperature regimes always produced optimum germination of 76 to 100%. We defined optimum as not statistically (p = 0.01) different from maximum. The always optimum temperature regimes were: (1) a constant 15 degrees C, (2) alternating 10/15 degrees C (16 hours cold/8 hours warm each day), and (3) 10/20 degrees C. When seed was produced in a year with good growing conditions, optimum germination extended over a wide range of temperatures. At optimum temperatures, the rate of germination was very rapid with a high percentage of total germination occurring within a week. The lack of inherent germination requirements that restrict germination, high germinability, and a rapid rate of germination help to explain the colonizing ability of this species.