• Range Resources of Iceland

      Thorsteinsson, I.; Olafsson, G.; Van Dyne, G. M. (Society for Range Management, 1971-03-01)
      Animal agriculture in Iceland is second only to fisheries. At least half the forage consumed by large herbivorous animals comes from rangelands. During the period June to September most of the sheep and large numbers of unbroken horses graze on mountain ranges where they roam freely in large grazing districts or commons. There is urgent need for land reclamation and range improvement. Only 25% of the country is covered with vegetation, much of which does not provide adequate protection against soil erosion and has low carrying capacity. With increasing population and demands upon rangelands for food production, an aggressive program of rangeland improvement and management, supported by adequate research, is essential.
    • Seed Dispersal in Relation to Rodent Activities in Seral Big Sagebrush Communities

      La Tourrette, J. E.; Young, J. A.; Evans, R. A. (Society for Range Management, 1971-03-01)
      Heteromyid rodents play an active role in the dispersal of caryopses and seeds of herbaceous species in degraded big sagebrush communities. Collections of caryopses of downy brome, deposited in caches, influence the dynamics of the grass population and the diet of animals on range sites in winter. Seeds and caryopses of alien weeds and exotic wheatgrasses were recovered more frequently from the pouches of rodents than seeds of native species.
    • Sheep Behavior Under Unherded Conditions on Mountain Summer Ranges

      Bowns, J. E. (Society for Range Management, 1971-03-01)
      Purebred Rambouillet, Targhee and Columbia sheep were observed on mountain summer ranges in southwestern Utah. Under unherded conditions Rambouillet sheep travelled greater distances and spent more time resting, while Columbias travelled the least distances, rested least and grazed longer than the other breeds. All breeds travelled farther in the morning than in the afternoon but grazed longer in the afternoon. There was a tendency for the sheep to water and take salt in the mornings rather than in the afternoons. Overgrazing on established bedgrounds was caused by animals grazing these areas in the evening prior to bedding down. Fencing along the crests of the ridges and more strategic salt placement appear to be the most useful means of improving distribution.
    • Spraying Tarweed Infestations on Ranges Newly Seeded to Grass

      Hull, A. C. (Society for Range Management, 1971-03-01)
      A high elevation, tarweed-infested range which had been newly seeded to grass was sprayed with 3 rates of 2,4-D at 2 growth stages of the seeded grass. 2,4-D at 0.5 lb./acre killed over 97% of the tarweed and 1 and 2 pounds killed 99 and almost 100, respectively. Rate of spraying when grasses had 1 to 2 leaves did not affect numbers of grass plants but killed more tarweed than did spraying when grasses had 2 to 4 leaves.
    • Thermal Regulation of Water Uptake by Germinating Honey Mesquite Seeds

      Scifres, C. J.; Brock, J. H. (Society for Range Management, 1971-03-01)
      Ambient temperature regulated the rate and extent of water imbibition by germinating honey mesquite (Prosopis glandulosa Torr., var. glandulosa) seeds. Honey mesquite seeds required less water and less time for germination at 85 than at 100 or 70 F. Seeds at 70 F contained almost 3 times as much water as seeds at 85 F when germination first occurred although the rate of water uptake (mg/seed/hr) was reduced considerably. Decreasing moisture availability to 8 atm influenced the rate of water absorption by seeds more at 85 and 100 F than at 70 F.
    • Timing Use of Cool- and Warm-Season Grasses on Pine Ranges

      Pearson, H. A.; Mann, J. F.; Howard, D. A. (Society for Range Management, 1971-03-01)
      A 3-pasture rest-rotation grazing system based on plant growth and development during 2 annual precipitation periods resulted in more equitable utilization of cool- and warm-season grasses (Arizona fescue and mountain muhly) on ponderosa pine range. Plant and cattle productivity were maintained and utilization of forage species was more uniform./El presente estudio se llevó a cabo en un tipo de vegetación de pino ponderosa (Pinus ponderosa) cerca de Flagstaff, Arizona, E.U.A. Los pastos de esta zona se caracterizan por una mezcla de zacates de verano e invierno. Esto dificulta el pastoreo uniforme de las especies debido a la mezcla. Este estudio significó que con un sistema de rotación con tres potreros se obtuvo mas uniformidad de pastoreo de los diferentes zacates. Las épocas de pastoreo y descanso fueron conforme a las épocas de crecimiento relacionadas a las épocas de precipitación.