• Carbohydrate Reserve, Phenology, and Growth Cycles of Nine Colorado Range Species

      Menke, J. W.; Trlica, M. J. (Society for Range Management, 1981-07-01)
      Nine Colorado range species were studied for two consecutive years to relate the carbohydrate reserve status with phenological stage of development and current annual growth, including leaf, twig, or seedstalk length, or plant height. The species were four-wing saltbush (Atriplex canescens), antelope bitterbrush (Purshia tridentata), little rabbitbrush (Chrysothamnus vicidiflorus), fringed sagewort (Artemisia frigida), scarlet globemallow (Sphaeralcea coccinea), blue grama (Bouteloua gracilis), western wheatgrass (Agropyron smithii), James' cryptantha (Cryptantha jamesii), and pricklypear cactus (Opuntia polyacantha and rhodantha in a mixed stand). Seasonal total nonstructural carbohydrate (TNC) reserve cycles were related to phenological stages of development. Growth of all species appeared to be stimulated by late-summer or fall precipitation. Growth was found to be related inversely to carbohydrate reserve storage. Fourwing saltbush and antelope bitterbrush had typical V-shaped annual carbohydrate reserve cycles, and little rabbitbrush had a somewhat flat or extended V-shaped cycle. Fringed sagewort, scarlet globemallow, and western wheatgrass had flat or extended V-shaped cycles and maintained low reserves for more of the growing season than any of the species with typical reserve cycles. Blue grama was the only species that exhibited a narrow V-shaped cycle. The shape of the seasonal TNC cycle appeared to be a good screening tool for assessing the relative effects of defoliation on different plant species. Plants that replenished reserves rapidly after spring draw-down and regrowth periods, and minimized the part of the growing season with low reserve status, were least affected by defoliation and recovered rapidly from severe defoliation.
    • Disagreement among Investment Criteria—A Solution to the Problem

      Workman, J. P. (Society for Range Management, 1981-07-01)
      Three standard investment criteria, benefit-cost ratio (B/C), internal rate of return (IRR), and present net worth (PNW), are commonly used for economic evaluation of range improvements. Unfortunately, as commonly calculated, these three criteria often yield contradictory selections when choosing between two or more possible range improvement projects. Disagreements among the three criteria are caused by differences in project lives and initial investments (size), along with failure to recognize explicitly the rate of return foregone on alternative investments. This paper demonstrates that when projects are normalized for non-uniform lives and differences in size, the three investment criteria yield identical project selections. Correct project selection by B/C requires normalization for non-uniform size, while the IRR calculations must be normalized for differences in both project size and expected life. The following procedure is recommended for selecting an optimum combination of projects from among numerous alternatives: (1) Rank projects by B/C. (2) Select best projects first until available capital is exhausted. (3) Perform PNW side calculations to verify the accuracy of the selected project combination.
    • Early Succession in Aspen Communities Following Fire in Western Wyoming

      Bartos, D. L.; Meuggler, W. F. (Society for Range Management, 1981-07-01)
      Aspen clones in varying degrees of deterioration were burned in northwestern Wyoming in an attempt to regenerate the site. Large numbers of aspen suckers are necessary to perpetuate these stands under current heavy ungulate use. Sucker numbers doubled the second year after burning and by the end of the third year had returned to near preburn levels of 15,000-20,000 suckers per hectare. This slight increase in sucker numbers is probably not sufficient to regenerate the stands under current browsing pressures. Total understory production declined the first year following fire and then increased to 3,600 kg/ha the second year-almost double preburn conditions. Production decreased the third year to about one-third greater than before burning. Forb and grass production increased and shrubs decreased as a result of burning. Fireweed (Epilobium angustifolium) was the largest post-fire contributor to total understory production.
    • Effects of a Wet-Dry Seed Treatment on the Germination and Root Elongation of "Whitmar" Beardless Wheatgrass under Various Water Potentials

      Kastner, W. W.; Goebel, C. J.; Maguire, J. D. (Society for Range Management, 1981-07-01)
      Seeds of Whitmar beardless wheatgrass (Agropyron spicatum f. inerme Beetle) were allowed to imbibe water at 20 degrees C for 24 hours, followed by air-drying at room temperature for 24 hours. Seeds were then placed in slanted-plate containers held at 20° C to measure germination and root elongation under water potentials of -0.3, -7.5, and -15 bars. Seed treatment significantly accelerated germination and root elongation under a water potential of -0.3 bars, with some acceleration occurring at -7.5 bars. Treatment did not accelerate growth activity under a water potential of -15 bars.
    • Effects of Cattle Grazing on Mountain Meadows in Idaho

      Leege, T. A.; Herman, D. J.; Zamora, B. (Society for Range Management, 1981-07-01)
      Vegetation changes which occurred during 12 years of protection from grazing were documented in mountain meadows of north-central Idaho. Plant composition changes were evident on all five sites studied, whereas herbage production was significantly less on the grazed than ungrazed areas at two of the sites. Season-long grazing by cattle has apparently been responsible for decreasing production and retarding plant succession. A change in grazing systems would likely increase the carrying capacity for herbivores.
    • Effects of Fall Clipping or Burning on the Distribution of Chemical Constituents in Bluebunch Wheatgrass in Spring

      Willims, W.; Bailey, A. W.; McLean, A.; Kalnin, C. (Society for Range Management, 1981-07-01)
      We examined the effects of fall clipping or burning on chemical constituents and their distribution in bluebunch wheatgrass the following spring. The study was made in both a big sagebrush-bluebunch wheatgrass and a Douglas fir-bluebunch wheatgrass community. The concentration of mineral constituents (nitrogen, phosphorus, calcium and magnesium) was lower while the concentration of fibrous constituents (acid detergent fiber, neutral detergent fiber and lignin) was higher in leafy material at the top of the plant. In the big sagebrush community, the differences among treatments were generally greater in the lower segments of plants. Generally, the mineral constituents increased while the fibrous constituents decreased from the control to the clipped to the burned treatment. The treatment effect was more variable in plants from the Douglas fir community.
    • Forage Quality of Western Wheatgrass Exposed to Sulfur Dioxide

      Milchunas, D. G.; Lauenroth, W. K.; Dodd, J. L. (Society for Range Management, 1981-07-01)
      Effects of three exposure levels of SO2 (55, 100, and 170 micrograms m-3) on the nutritive value of western wheatgrass were investigated. Significant increases in plant sulfur content were observed, both with time and level of SO2 exposure. Plant ash content paralleled the trends observed for sulfur concentrations. Nitrogen concentrations in western wheatgrass were not affected by SO2 treatments. The increased plant sulfur content and decreased N:S ratios across treatments did not significantly affect forage digestibility as measured by in vitro digestible dry matter.
    • Grazing Systems: Their Influence on Infiltration Rates in the Rolling Plains of Texas

      Wood, M. K.; Blackburn, W. H. (Society for Range Management, 1981-07-01)
      Water infiltration rates into soils after 30 min in shrub canopy areas and in shortgrass interspaces on the Rolling Plains were similar across grazing treatments of heavy and moderate stocking, continuous grazing; rested and grazed deferred-rotation; rested and grazed high intensity, low frequency (HILF); and two live-stock exclosures which had been grazed for 20 years. The mid-grass interspace infiltration rates for the deferred-rotation treatments approached rates in the exclosures and exceeded rates in the heavily stocked, continuously grazed, and grazed HILF pastures. Infiltration rates in the HILF grazing treatments were similar to those of the heavily stocked, continuously and moderately stocked continuously grazed pastures. Infiltration rates in the rested HILF pasture were similar to those of the deferred-rotation pastures; however, the grazed HILF pasture had rates lower than the deferred-rotation pasture rates or rates of the exclosures. Aggregate stability, organic matter content, mulch, standing crop, bulk density, and ground cover significantly influenced infiltration rates.
    • Plot Delineation with a Pin-and-Chain

      Baker, R. L.; Pearson, H. A. (Society for Range Management, 1981-07-01)
      The pin-and-chain is currently being used to delineate sampling plot boundaries in Southern forest-range where conventional rigid plots would be impractical. The pin-and-chain method can be used for delineating both circular and rectangular plots.
    • Rangeland Seeder Development Using Semicircular Seedbox and Auger Agitator Seed Metering Concept

      Wiedemann, H. T.; Cross, B. T. (Society for Range Management, 1981-07-01)
      A rangeland seeder featuring a semicircular seedbox and auger agitator mounted to heavy-duty frame has proven reliable and durable under rough rangeland conditions. The experimental seeder reduces the variability in metering fluffy seed due to the improvement in design. Satisfactory metering of slick seed was accomplished with a commercial, cup-feed mechanism. Flexing, runner openers prepared and placed seed in a furrow without undue mechanical breakage while traversing logs, stumps and other debris left after rootplowing. The features of the experimental seeder increase the potential for seeding brush-infested rangeland because of improved reliability and less need for costly clean-up of brush debris.
    • Responses of Annual Range Grasses and Legumes to Comparable Applications of Manurial and Inorganic Fertilizers

      Jolley, L. W.; Raguse, C. A. (Society for Range Management, 1981-07-01)
      The use of cattle manure as an alternative to commercial inorganic fertilizer for annual rangelands was investigated, using mixtures of annual range grasses and legumes grown in pots containing a range soil known to be low in nitrogen and phosphorus and marginal in sulfur. Equivalent applications were made of N, P, and S over a wide range of levels (ca 100-1,200 kg/ha N, 23-276 kg/ha P, and 17-200 kg/ha S equivalents) with the N:P:S ratios of the inorganic fertilizer treatments adjusted to match those of the manure. All levels of both fertilizer types were applied either soil-incorporated or surface-broadcast. Plants were grown in greenhouse and outdoor environments, harvested twice, and separated into grass and legume components. Total yields and grass vields were higher for inorganic fertilizer. Clover yields were higher in the manure treatments, and in the outdoor environment, and increased from the first to the second harvests. Yields generally increased from first to second harvests and were higher in the outdoor environment. Mode of application had little effect on either yield or grass:legume ratio. Where economically feasible and available, the use of manures on rangeland may be justified, especially where enhancement of a legume component of the vegetation is desired.
    • Seasonal Vegetative Establishment and Shoot Reserves of Eastern Gamagrass

      DeWald, C. E.; Sims, P. L. (Society for Range Management, 1981-07-01)
      Seasonal vegetative establishment and shoot reserves of eastern gamagrass were studied at Woodward, Oklahoma. Single shoots and compound shoots were separated from parent plants and field transplanted twice monthly from January 1977 through September 1978. Shoot reserves were estimated by measurements of mass and percent new growth under etiolation, percent dry matter, and amount and percent total nonstructural carbohydrate (TNC). Etiolated growth, percent dry matter, and TNC were greatest during the winter dormant season and least during May and June. Stand establishment from vegetative propagation followed these same trends, indicating the importance of shoot reserves to vegetative propagation. Etiolated growth followed the same seasonal trends as TNC in shoots but had higher values, indicating that reserves other than carbohydrates measured in the TNC analysis may be important in new shoot growth of eastern gamagrass. Single shoots with high dry weights contained greater amounts of reserves than shoots with low dry weight sampled during the same period. Stand establishment was higher for compound than for single shoots from late June through September, apparently because compound shoots weighed more and contained more reserves than single shoots. Shoots of eastern gamagrass transplanted during the winter dormant season resulted in 90-100% establishment. Vegetative propagation could become an important means of establishing eastern gamagrass if suitable field transplanting equipment were developed. Eastern gamagrass has the potential to become a leading forage producer and engineering research to develop suitable propagation equipment is justified.
    • Streambank Erosion and Ungulate Grazing Relationships

      Buckhouse, J. C.; Skovlin, J. M.; Knight, R. W. (Society for Range Management, 1981-07-01)
      Streambank erosional patterns have been studied for 3 years (1 year of calibration and 2 years of active grazing treatment) on the Starkey Experimental Forest and Range in the Blue Mountains of northeastern Oregon. Livestock grazing use at the rate of 3.2 ha/AUM (8 acres/AUM) has not accelerated streambank degradation on Meadow Creek. Most erosion occurred during wintering periods and this erosion has been independent of grazing season treatments. It appears that high runoff and occasional ice flows are the most significant factors in bank cutting on this stream.
    • The Effect of Slide and Frequency Observation Numbers on the Precision of Microhistological Analysis

      Holechek, J. L.; Vavra, M. (Society for Range Management, 1981-07-01)
      The number of slides and frequency observations per slide required for microhistological analysis was determined. Slides should be prepared so that at least 20 frequency observations are recorded per slide. When five slides were prepared per sample, reasonable estimations were obtained for species comprising 20% or more of the diet. Minor and trace species in the diet were poorly estimated indicating a large number of slides are needed for adequate precision.
    • The Oxalate, Tannin, Crude Fiber, and Crude Protein Composition of Young Plants of Some Atriplex Species

      Davis, A. M. (Society for Range Management, 1981-07-01)
      Oxalate, tannin, crude fiber, and crude protein contents were determined in 11 introduced Atriplex species and four species native to western North America that might be browsed by wildlife and livestock. Atriplex species of foreign origin resembled domestic species in content of oxalate, tannins, crude fiber, and crude protein, with averages and range similar to those of A. canescens. These foreign species could fit into a range ecosystem to improve the quality and quantity of different browse species.
    • The Productivity and Nutritive Value of Imperata cylindrica (L) Beauv. in the Thai Highlands

      Falvey, J. L.; Hengmichai, P.; Pongpiachan, P. (Society for Range Management, 1981-07-01)
      The rate of dry matter production after the annual pre-wet season burning, the rate of regrowth after cutting at three times during the year and the nitrogen content, phosphorus content and in vitro digestibility of Imperata cylindrica were studied in highlands of north Thailand over a one-year period. Dry matter production was slower than that recorded in more tropical regions and nitrogen content and digestibility correspondingly remained higher for longer. It is suggested that the slower growth rates recorded in this environment, permitted Imperata to remain a useful forage for a longer period than is usually considered possible for this species.
    • Tree Age and Dominance Patterns in Great Basin Pinyon-Juniper Woodlands

      Tausch, R. J.; West, N. E.; Nabi, A. A. (Society for Range Management, 1981-07-01)
      Prior studies of pinyon-juniper woodlands at a few locations have indicated considerable historical expansion of the trees and loss of understory. Whether these changes are a widespread phenomenon and related to pervasive, rather than local, influences was the question asked by this research. An objective sampling of 18 randomly selected mountain ranges in the Great Basin was undertaken. Tree age and dominance in the pinyon-juniper woodlands showed definite geographical, elevational, and historical trends. The oldest, most tree-dominated woodlands were located in areas of intermediate topography where disturbances may have been less frequent. Populations of both tree species [Pinus monophylla (Torr.) and Juniperus osteosperma (Torr. and Frem.)] were progressively younger and less dominant in both upslope and downslope directions from the intermediate elevations. Tree densities have also historically increased within the oldest woodlands. Pinyon density has increased faster than that of juniper. Approximately 40 percent of the sampled plots had their trees establishing during the last 150 years. These changes generally coincide with introduction of heavy livestock grazing, tree utilization by the mining industry, and fire suppression that followed settlement of the region. Associated climatic trends were also investigated. The relative importance of these influences on the changes in tree age and dominance cannot be determined without further research. The loss of understory, coincident with increasing tree dominance, has reduced forage production and made the woodlands progressively less susceptible to fire. Barring some major environmental change or management action, this forage reduction and decreased frequency of burning will continue until trees dominate much more area.
    • Variation in Defecation Rates of Pronghorns Relative to Habitat and Activity Level

      Irby, L. R. (Society for Range Management, 1981-07-01)
      During June through September, 1977, pronghorn antelope (Antilocapra americana) were observed in the National Bison Range, Moiese, Montana, to determine if defecation rates were constant in different habitat types and at different levels of activity. Individuals and groups that were active 50% or more of observation periods were found to have defecation rates approximately 10 times greater than groups or individuals that were active less than 50% of observation periods. Habitat type was much less tightly related to defecation frequency than was activity level.