• Composition and Quality of Mule Deer Diets on Pinyon-Juniper Winter Range, Colorado

      Bartmann, R. M. (Society for Range Management, 1983-07-01)
      Estimates of botanical composition and nutritional quality of mule deer diets on pinyon-juniper winter range in Piceance Basin, Colorado, were based on forage selections of 8 tame animals. Diets contained nearly all browse in early winter, but browse content decreased and forbs increased as winter progressed until April when consumption of new grass growth increased sharply. Dietary crude protein levels were marginally adequate for body maintenance during much of the winter. Levels of dietary in vitro digestible dry matter were inadequate. Browse was considered critical to winter survival of deer in Piceance Basin because it was the most available forage in deep snow. Also, its nutritional value was comparable or better than that of forbs and grasses selected by deer except in April when new plant growth was available. In spite of large variation in diet compositions, deer apparently selected forage mixes to maintain a consistent, although inadequate, diet quality through the critical wintering period.
    • Desert Saltgrass Seed Germination and Seedbed Ecology

      Cluff, G. J.; Evans, R. A.; Young, J. A. (Society for Range Management, 1983-07-01)
      Desert saltgrass [Distichlis spicata var. stricta (Torr.) Beetle] is an important forage species of the saline-alkali basins of the western United States. Revegetation of disturbed sites using saltgrass currently involves the use of rhizomes, but seeding saltgrass with conventional equipment would be much more efficient. The seed and seedbed ecology of desert saltgrass is important to land managers who wish to try new revegetation techniques. The germination of nine collections of saltgrass seed was determined at a wide range of constant and alternating temperatures. The effects of decreasing osmotic potentials on seed germination of one collection was determined using polyethylene glycol and sodium chloride solutions. Seedbed temperatures and moisture potentials were determined during the growing season in two saltgrass stands using thermocouple temperature probes and psychrometers. The temperature regime that produced the highest mean germination (58%) for all nine collections was 10 degrees C for 16 hours alternating with 40 degrees C for 8 hours (10/40 degrees C). Germination response varied significantly (P=0.01) between collections. The best germination was 96% with one collection at the 10/50 degrees C regime, but most collections germinated best with 10/40 degrees C regime. For all collections, at least a 20 degrees C diurnal fluctuation in temperature was needed for germination above 10%. Seeds did not germinate at temperatures as cold as -5 degrees C or as hot as 60 degrees C. Saltgrass germination was enhanced at osmotic potentials of -1 bar, but inhibited by potentials lower than -1 bar. No significant (P=0.01) germination occurred at -15 bars. Field seedbed temperatures reached optimum levels for germination after moisture potentials were below that required for germination. This suggests that saltgrass seed germination is an episodic event in nature, occurring only when moisture events coincide with optimum seedbed temperatures and can leach sufficient salts to raise moisture potentials above -15 bars.
    • A Mechanical Animal-powered Cow Spacer

      Anderson, D. M.; Mertz, D. I. (Society for Range Management, 1983-07-01)
      The low-cost, practical, easy-to-build, low-maintenance mechanical animal-powered cow spacer described spaces animals that are moving single file through a chute. The spacer unit can be used successfully in conjunction with an automatic electronic weighing/identification system for obtaining accurate daily weight data on individual animals.
    • A Method for Mapping Vegetation Utilizing Multivariate Statistical Techniques

      McLendon, T.; Dahl, D. E. (Society for Range Management, 1983-07-01)
      Principal component analysis and stepwise discriminant analysis were used to map the vegetation of the Pat Welder Ranch on the Texas Coastal Plains into 5 vegetation types based on relative frequency data of the major plant species. These 5 types were shown to be subdivisions of 2 plant communities previously reported for the area by researchers utilizing conventional mapping techniques. In addition to separating the 5 types and classifying the 140 sample points into their respective types, the technique provided a key for field separation of the types based on 3 vegetative variables, and provided indicator species values for rapid field identification of the types. The technique is presented as a means of mapping vegetation with a minimum of human bias, a maximum of repeatability and information content, and maximum applicability.
    • A Comparison of Three Methods for Estimating Forage Disappearance

      Sharrow, S. H.; Motazedian, I. (Society for Range Management, 1983-07-01)
      Three methods of calculating forage disappearance from forage standing crop present on mowed versus protected plots were compared to the actual amount of forage harvested from mowed plots. The method most widely used by range scientists, the difference method, displayed a marked tendency to overestimate forage disappearance during periods of rapid plant growth or when plots were protected for more than 3 weeks. More accurate estimates of forage disappearance were generally obtained using formulae suggested by Linehan et al. (1947) and Bosch (1956) than could be obtained by the difference method.
    • Effect of Cultural Practices on Seeded Plant Communities on Intensively Disturbed Soils

      Doerr, T. B.; Redente, E. F.; Sievers, T. E. (Society for Range Management, 1983-07-01)
      A revegetation technique study was established in a disturbed sagebrush-juniper community in northwestern Colorado in the fall of 1976. The purpose of the study was to identify effective cultural practices for establishing diverse and productive plant communities on disturbed soils. A combination of 4 treatments was applied: (1) altering life form seeding ratios, (2) seeding mixtures, (3) fertilizer, and (4) irrigation. After 4 years there was no significant difference in aboveground biomass production and canopy cover between irrigated and nonirrigated treatments. Fertilization increased production of grasses and shrub growth but depressed forb growth somewhat. The aboveground production of native and introduced mixtures was similar following four growing seasons. In general, introduced grasses out-produced native grasses, introduced forbs produced more than native forbs, and native shrubs out- performed introduced shrubs. Altering ratios among life forms affected shrub biomass more than forb and grass production. The use of different seeding rates indicates that plant community composition will change and may be a function of not only seeding rates but also plant and environmental factors over time and space.
    • Gains of Steers and Calves Grazing Crested Wheatgrass

      Hart, R. H.; Balla, E. F.; Waggoner, J. W. (Society for Range Management, 1983-07-01)
      Efficient utilization of pasture requires proper class of livestock, stocking rate, and season of use. Crested wheatgrass was grazed with steers in spring for 3 years at two stocking rates and with calves in fall for 2 years at 2 stocking rates to evaluate alternate uses. Differences in forage production and lengths of grazing season over years produced grazing pressures of 47-79 steer days or 53-73 calf days per metric tonne of forage produced. Steer gains of 0.85-1.20 kg/day were unaffected by grazing pressure, but lighter steers gained faster. Implantation of 36 mg of Ralgro per steer increased daily gains by 13%. Calf gains were 0.15-0.24 kg/day, and decreased with increasing grazing pressure according to the function ADG=0.45-0.0041 (calf days/tonne forage); r2=0.95. Such grazing pressure-gain response functions facilitate comparisons between seasons of use and class of livestock, as well as those between stocking rates, and help range managers make management decisions. Maximum steer gains in spring per hectare and tonne of forage were over 3 and 6 times, respectively, the gains of calves in fall.
    • Herbicidal Control of Common Broomweed

      Boyd, W. E.; Herndon, E. B.; Sosebee, R. E. (Society for Range Management, 1983-07-01)
      Common broomweed (Amphiachyris dracunculoides) infests Texas rangelands during the fall, winter, or spring in years with abundant soil water. Herbicidal control of common broomweed was studied in the Rolling Plains of Texas in 1977, a wet year. Dicamba and picloram plus 2,4,5-T effectively controiled broomweed at rates ranging from 0.14 to 1.1 kg a.i./ha. Tebuthiuron produced less consistent control and 2,4-D was ineffective at rates from 0.14 to 1.1 kg/ha. Broomweed production was reduced and grass production increased regardless of whether dicamba or picloram plus 2,4,5-T were applied in early December, late January, or mid-May. Grass production increased 1.5 fold following broomweed control. Compared to untreated plots, neither soil water content nor soil temperature were affected by broomweed reduction, but photosynthetic active radiation reaching more desirable forage was significantly increased by broomweed control.
    • Fiber Effects on Microhistological Analysis

      Mukhtar, H. K.; Hansen, R. M. (Society for Range Management, 1983-07-01)
      A study was done to illustrate the influence of fiber on the ratio of estimated to actual dry weight fractions of selected species of grasses, forbs, and shrubs in samples analyzed by microhistological analysis. There was no significant relation between the fiber fraction of the plants and the over or under estimations. Forbs were not generally underestimated any more than were grasses or shrubs. The hypothesis is rejected which states that plants with low fiber values are usually underestimated by the microhistological technique.
    • Estimating Snowberry (Symphoricarpos oreophilus) Utilization by Sheep from Twig Diameter-Weight Relations

      Ruyle, G. B.; Bowns, J. E.; Schlundt, A. F. (Society for Range Management, 1983-07-01)
      Three procedures were used to estimate snowberry biomass browsed at 3 stocking intensities by domestic sheep on mountain range in southwestern Utah. Two regression equations and (percentage of) grazed stems were compared. Each technique gave different estimates of utilization, which were affected by grazing intensity. The two regression equations we developed distinguished between two kinds of sheep browsing, leaf only and entire stem removal. Sheep usually strip only the leaves and rarely is the entire stem removed. The predictive equations accounted for both methods of browsing and related twig diameters to twig leaf weight (R2=.89) and twig plus leaf weight (R2=.90).
    • Food Habits of Mountain Goats, Mule Deer, and Cattle on Chopaka Mountain, Washington, 1977-1980

      Campbell, E. G.; Johnson, R. L. (Society for Range Management, 1983-07-01)
      The seasonal food habits of mountain goats, mule deer, and cattle on Chopaka Mountain, Wash., (1977-1980) were determined by fecal analysis. Graminoids represented 84% of the fall diet of cattle, the only period when cattle occurred within the mountain goat range. Mountain goats utilized graminoids (42%) and shrubs (31%) primarily; whereas, mule deer consumed shrubs (45%) and conifers (29%). Dietary overlap was greatest between mt. goats and mule deer (37%) and mt. goats and cattle (32%), and minimal between mule deer and cattle (15%). Considerable intra- and inter-seasonal variation was experienced for all 3 species.
    • Habitat Differences Between Basin and Wyoming Big Sagebrush in Contiguous Populations

      Barker, J. R.; McKell, C. M. (Society for Range Management, 1983-07-01)
      Basin and Wyoming big sagebrush plants growing in contiguous populations were studied to identify potential habitat differences in plant water and soil relationships. At 3 study sites, basin big sagebrush plants were growing in and adjacent to a drainage, while Wyoming big sagebrush plants occupied areas adjacent to the basin big sagebrush populations. Soil- and leaf-water potentials and leaf-transpiration resistances were measured from May to October 1980 to identify differences between basin and Wyoming big sagebrush plant-water relationships. Soil identification and plant tissue analyses were conducted to help characterize edaphic differences between the subspecies. The results of these studies showed that basin big sagebrush plants grew in a more mesic and fertile habitat than did Wyoming big sagebrush plants. Understanding the environmental differences of these two big sagebrush subspecies is important in effectively managing basin and Wyoming big sagebrush ranges.
    • Mastication Effects on Cattle Diet Determined by Microhistological Analysis

      Gross, B. D.; Mahgoub, E.; Holechek, J. L. (Society for Range Management, 1983-07-01)
      This study examined the influence of mastication on the composition of several hand compounded diets fed to esophageally fistulated cattle. Microhistological analysis was used to determine diet sample botanical composition. Mastication had no effect on diet botanical composition. However, considerable variation existed between observers. The use of observers demonstrating high accuracy with hand compounded mixtures and replication of observers are possible ways to maintain accuracy when microhistological analysis is used to evaluate herbivore diets.
    • Mule Deer Preference and Monoterpenoids (Essential Oils)

      Welch, B. L.; McArthur, E. D.; Davis, J. N. (Society for Range Management, 1983-07-01)
      Wild wintering mule deer browsed on a uniform shrub garden near Helper, Utah. On this garden, 21 accessions from 5 Artemisia taxa were selected to test the relationship between deer preference for these accessions and the amount of monoterpenoids present in the accessions. Deer preferences were determined by measuring removal of current year's growth. Samples of current year's growth (leaves and stems with terminal buds) were collected at the time preference measurements were taken to determine monoterpenoid content. Deer use ranged from zero to 83% of the current year's growth. Total monoterpenoid content among accessions varied from 0.75 to 3.62% of dry matter. Coefficients of determination, preference versus monoterpenoid levels (total and individual) ranged from 0 to 18%. The monoterpenoid content of various accessions of Artemisia taxa was not significantly related to deer preference.
    • Nutrient and Sediment Discharge from Southern Plains Grasslands

      Smith, S. J.; Menzel, R. J.; Rhoades, E. D.; Williams, J. R.; Eck, H. V. (Society for Range Management, 1983-07-01)
      Amounts of nitrogen, phosphorus, and sediment were measured in runoff from grassland watersheds in the Blackland Prairies, High Plains, Reddish Prairies, and Rolling Red Plains land resource areas of Oklahoma and Texas. Periods of study were 3 to 5 years and included treatments involving fertilization, cultivation, and burning. Overall nutrient concentrations generally ranged from 2 to 10 mg/l for nitrogen and 0.3 to 2 mg/l for phosphorus. In most cases, less than half the nutrients existed as soluble forms in the runoff water. Typically, annual sediment losses were less than 0.5 metric tons/ha. Corresponding losses for nitrogen and phosphorus were less than 5 and 2 kg/ha, respectively. In the case of nitrate, more was received in precipitation than was lost in runoff. Total nitrogen and phosphorus losses were strongly correlated with sediment losses. Preliminary results using predictive techniques to estimate nutrient and sediment discharge from the watersheds were encouraging. With proper management, the likelihood of any adverse environmental effects due to nutrient and sediment discharge from Southern Plains grasslands appears slight.
    • Predicting Soluble Nitrogen and Fibrous Fractions in Crested Wheatgrass with Near-Infrared-Reflectance Spectroscopy

      Park, Y. W.; Anderson, M. J.; Asay, K. H.; Mahoney, A. W. (Society for Range Management, 1983-07-01)
      A near-infrared-reflectance (IR) spectroscopic method was evaluated for potential usage in predicting soluble N, total N and some fibrous fractions in crested wheatgrass, Agropyron cristatum (L.) Gaertn., A. desertorum (Fisch. ex Link), et al. The correlation coefficients (r) between IR and total N, soluble N in 0.15N NaCl (N Sal), soluble N in 10% Burroughs Mineral Mixture solution (NBMM), neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) for 84 samples were 0.95, 0.90, 0.70, 0.90, 0.82, and 0.72, respectively. The IR technique provided a closer estimation of total N and N Sal than of NBMM in the calibration data. The mean solubility of N Sal was higher than that of NBMM. High variation occurred between the duplicate determinations of NBMM. The predictions on 30 unknown samples by the equation developed using 84 calibration samples for mean, SED (standard error of difference), and r were: total N, 1.01, 0.04, 0.98; N Sal, 0.43, 0.04, 0.90; NDF, 64.1, 0.96, 0.93, ADF, 36.2, 1.01, 0.91; and ADL, 5.24, 0.53, 0.62. Predictions of fibrous fractions were highly satisfactory even though the correlations were low. Correlations between chemical determinations of total N and N Sal, NBMM, NDF, ADF, ADL were 0.89, 0.53, -0.13, -0.33, -0.08, respectively. Significant differences (P<0.01) were found among crested wheatgrass species for all nitrogenous and fibrous fractions measured. Differences among clonal lines within species were also significant (P<0.05 or 0.01) for all determinations indicating that opportunities are available to improve the nutritional value of crested wheatgrass through selection.
    • Response of Soft Chess (Bromus mollis) and Slender Oat (Avena barbata) to Simulated Drought Cycles

      Ewing, A. L.; Menke, J. W. (Society for Range Management, 1983-07-01)
      Herbage production in the California annual grassland has been correlated with seasonal weather, particularly fall and spring rainfall patterns. To further examine the relationship between herbage production and rainfall pattern, 3 soil water regimes (-1, -7, -15 bars) simulating expected rainfall and drought events in annual rangelands were applied in seminatural annual grassland communities. Soft chess (Bromus mollis) tillers grew longest under the -7 bar water regime treatments while total plant growth was greatest under the -1 bar treatment. Tiller length and total growth of slender oat (Avena barbata) were greatest under the -1 bar treatment. Vegetative growth of slender oat was less sensitive to season-long soil water regimes than soft chess. The two species required different soil water conditions for maximum spring growth; soft chess put on spring growth most rapidly in the -7 bar treatment while slender oat grew fastest in the -1 bar treatment. Periodic water stress during the growing season did not reduce spring herbage production. Maximum growth and herbage production occurred only when soil water was available after March 15. Withholding water after March 15 reduced herbage production by 46%.
    • Seasonal Variation of Monoterpenoids in Big Sagebrush (Artemisia tridentata)

      Cedarleaf, J. D.; Welch, B. L.; Brotherson, J. D. (Society for Range Management, 1983-07-01)
      Monthly monoterpenoid content was determined for 16 big sagebrush (Artemisia tridentata) plants grown on a uniform garden. These 16 plants were selected at random from 4 accessions of basin big sagebrush (A.t. ssp. tridentata)-4 plants per accession. A composite sample was taken for a fifth accession of mountain big sagebrush (A.t. vaseyana). Monoterpenoid content varied seasonally with the lowest content occurring during May (0.97% of dry matter). Highest monoterpenoid content occurred during July (4.18%) followed by August (3.36%) and September (2.73%). Dove Creek (2.61% of dry matter) and Marysvale (2.64%) basin big sagebrush accessions contained significantly higher pooled levels of monoterpenoids than the Indianola (1.73%) and Loa (1.55%) big sagebrush accessions. The composite samples of the Indian Peaks mountain big sagebrush accession, an accession significantly preferred over the Marysvale and Loa accessions, contained an overall monoterpenoid level of 2.82%. Adverse relationships between monoterpenoid content and the consumption of big sagebrush by wintering mule deer seem weak.