• Rabbits as a Tool in Pasture and Range Utilization Research

      Hedrick, D. W. (Society for Range Management, 1957-07-01)
    • Rabies in Rangeland Environments

      Young, James A. (Society for Range Management, 1984-04-01)
    • Radiant Temperatures of Hair Surfaces

      Moen, Aaron N. (Society for Range Management, 1974-09-01)
      The radiant temperatures T(r) of the surfaces of winter pelage of white-tailed deer, mule deer, snowshoe hare, cottontail rabbit, and red fox decrease with a decrease in air temperature T(a) and an increase in wind velocity (U). The relationship between T(r) and T a is linear, but nonlinear for T(r):U. Changes in the lower velocities have a relatively greater effect than changes in the higher velocities. The variation between species results in considerable overlap; the use of thermal scanning techniques for censusing of these different species is doubtful under most field conditions.
    • Radioisotope Uptake Bb Selected Range Forage and Weed Species

      Eckert, R. E.; Blincoe, C. R. (Society for Range Management, 1970-09-01)
      Two wheatgrasses, one annual grass, and one annual forb were used to evaluate the uptake of fourteen gammaemitting isotopes from an important range soil. Uptake of copper, molybdenum, and selenium ranged from moderate to very good from all soil horizons. Uptake of iodine and chromium was poor from the surface and lower soil horizons, respectively, but moderate to very good from other horizons. Other desirable characteristics of these isotopes for root-tracing studies are half-lives of from 12.8 hours to 128 days, and energy differences which permit detection of each isotope in the presence of others.
    • Radiometric Reflectance Measurements of Northern Great Plains Rangeland and Crested Wheatgrass Pastures

      Aase, J. K.; Frank, A. B.; Lorenz, R. J. (Society for Range Management, 1987-07-01)
      Calculated reflectance factors and vegetation indices derived from radiometric reflectance measurements were used in regression analyses to test for a single relationship between canopy reflectance characteristics and measured vegetation parameters from 1 moderately grazed and 1 heavily grazed native rangeland pastures and 1 crested wheatgrass [Agropyron desertorum (Fisch. ex Link) J.A. Schultes] pasture. The study was located on a Williams loam (fine-loamy mixed, Typic Argiboroll) near Mandan, North Dakota. Reflectance measurements were made near solar noon once a week during the 1983 and 1984 growing seasons. There was a statistically significant relationship (r=0.76**) between leaf area index and dry green matter among pastures and years. However, each pasture exhibited a unique relationship (statistically significant) between vegetation indices developed from the reflectance measurements and leaf area index or dry green matter. Based on the techniques and wavebands used in this study, over a given geographic region and with pasture management practices known, it may be possible to remotely estimate green dry matter.
    • Radiometry for predicting tallgrass prairie biomass using regression and neural models

      Olson, K. C.; Cochran, R. C. (Society for Range Management, 1998-03-01)
      Standing forage biomass (SFB) and the percent of standing biomass composed of forbs (PCTF) were modeled across the growing season. Samples representing stages of plant maturity from early vegetative to dormant were collected from grazed and ungrazed native tallgrass paddocks using a 0.5 X 0.5 m quadrat. Total biomass was measured during all years of the study (1992-1995). Grass and forb biomass were measured separately during 1995. Height of canopy closure also was measured during 1995. Before clipping, plots were scanned with a multispectral radiometer. Models were prepared using simple regression, multiple regression (MR), or a commercial neural network (NN) computer program. Potential inputs to MR and NN models of SFB and PCTF included Julian day of harvest (JD), range site, canopy closure height (CH), incident radiation, spectral reflectance values (RFV) at 8 discreet bandwidths, and the normalized difference vegetation index (NDVI). The NDVI alone accounted for little variability (R2 = 0.13) in SFB during all years of the study. The optimal MR model for the same data set (SFB = 3.5[JD] - 43.7[460 nm RFV] + 1099[NDVI] - 992; R2 = 0.62) accounted for a greater amount of the variability in SFB. The capacity to describe variation in SFB for the 1995 data with MR was improved when CH was included as a variable (R2 = 0.58 versus 0.78). A NN model accounted for the most variation in SFB across the entire study (R2 = 0.76). During 1995, the capability of a NN to account for variation in SFB within the training data was similar whether or not CH was included as an input (R2 = 0.86); however, prediction of SFB from validation data using the same NN was improved by using CH as an input variable. Little variation in PCTF was accounted for by a MR model (R2 = 0.23); however, a considerably larger proportion of the variation in PCTF was accounted for when an NN was used (R2 = 0.59). Seasonal changes in SFB and PCTF were described with an acceptable degree of accuracy by forage reflectance characteristics that were adjusted for time of season and canopy complexity. Moreover, when provided with the same potential inputs, NN predicted SFB and PCTF from validation data more accurately than MR models.
    • Rainfall Effects on Soil Surface Characteristics Following Range Improvement Treatments

      Kincaid, D. R.; Williams, G. (Society for Range Management, 1966-11-01)
      Range improvement treatments-brush clearing, pitting, and seeding to grass-were imposed on twenty-four 6 by 12-foot plots near Tombstone, Arizona. One summer's rainfall of average amount and intensity reduced roughness due to pitting; and such other surface characteristics as erosion pavement and exposed soil approached a state of stability similar to the untreated plots. Surface runoff exhibited little correlation with treatment, but showed a statistically significant negative correlation with crown cover of vegetation.
    • Rainfall Interception by Cool-desert Shrubs

      West, N. E.; Gifford, G. F. (Society for Range Management, 1976-03-01)
      Interception patterns of big sagebrush (Artemisia tridentata Nutt.) and shadscale (Atriplex confertifolia (Torr.) Wats.) were measured under two simulated rainfall intensities during three different seasons. Mean rainfall interception rate of individual plants of both species was 0.15 cm when averaged over all sampling dates and rainfall intensities. Interception during individual storms of at least 0.15 cm size by entire plant communities, based on measured vegetal cover, was calculated at 0.028 cm or less. On the average, about 4% of the total annual rainfall (not snowfall) would be intercepted by these plant communities.
    • Rainfall Interception by Midgrass, Shortgrass, and Live Oak Mottes

      Thurow, T. L.; Blackburn, W. H.; Warren, S. D.; Taylor, C. A. (Society for Range Management, 1987-09-01)
      Interception, as a function of simulated rainfall intensity and duration, was determined for a midgrass [sideoats grama (Bouteloua curtipendula (Michx.) Torr.)] and a shortgrass [curleymesquite (Hilaria belangeri (Steud.) Nash)]. In addition, the redistribution of natural precipitation via plant interception was determined for live oak (Quercus virginiana Mill.) mottes. Interception storage capacity for sideoats grama and curleymesquite was 81 and 114% of dry weight, respectively. This difference was attributed to physical characteristics of the species and their respective growth forms. However, because sites dominated by sideoats grama had more standing biomass (3,640 kg ha-1) than sites dominated by curleymesquite (1,490 kg ha-1), it was estimated that a sideoats grama dominated site had an interception storage capacity of 1.8 mm compared to curleymesquite dominated site with an interception storage capacity of 1.0 mm. Based upon precipitation event size and distribution for the study site at the Texas Agricultural Experiment Station near Sonora, Texas, the estimated interception loss for curleymesquite dominated sites was 10.8% of annual precipitation, compared to 18.1% interception loss for sideoats grama dominated sites. Only 54% of the annual precipitation reached mineral soil beneath the oak mottes as throughfall or stemflow. The remainder of the precipitation was intercepted by the motte canopy or litter layer and evaporated. Due to the water concentrating effect of stemflow, soil near the base of trees received about 222% of annual precipitation. Soil at a distance greater than approximately 100 mm from a tree trunk received only 50.6% of annual rainfall. Individual tree canopy width, height and depth measurements were insignificant predictors of stemflow and throughfall. Interception, throughfall and stemflow, expressed as percent of storm precipitation, were well-defined curvilinear functions.
    • Rainfall interception by selected plants in the Chihuahuan Desert

      Wood, M. K.; Jones, T. L.; Vera-Cruz, M. T. (Society for Range Management, 1998-01-01)
      Water budget modeling usually requires quantification of all possible processes of the hydrologic cycle. This includes rainfall interception. The purpose of this study was to estimate the potential amounts of water transferred back to the atmosphere from interception for some common plants found in the Chihuahuan desert. Fifty plants of many sizes representing 10 common species of the Chihuahuan Desert were chosen for evaluation. Plants were submerged in a 2 X 2 m tank filled with water. After submersion, the plants were weighed, and the difference in weight was recorded as the maximum water storage capacity of the plant's canopy. Plants were also measured for maximum and minimum crown diameter (cm), height (cm), green weight (g) at time of submersion, and oven-dry weight (g). The forb, grass, and shrub species had different variables included in the prediction equations. Dry and green weight were the 2 variables which appear to have the strongest relationship with the amount of water intercepted for all species. Of the 7 grass species evaluated, dry and green weight were part of all equations, and height was included in only 2 equations.
    • Rainfall Pattern and Monthly Forage Yields in Thal Ranges of Pakistan

      Khan, C. M. A. (Society for Range Management, 1971-01-01)
      The multiple correlation and multiple regression between monthly forage yield of dhaman (Cenchrus ciliaris Linn.) and the four factors of the amount of monthly rainfall, the number of rainy days in the month, the amount of rainfall during the previous month and the month of the growing period were positive and highly significant (0.01 level). The same multiple relationships for karera (Elyonurus hirsutus Vahl.) were significant only if rainfall during the previous month was not included. There were highly significant positive correlation and regression relationships between forage yield and monthly rainfall, for both species. For either species, positive significant correlation existed betwen monthly forage yields and number of rainy days. Dhaman was more responsive than karera to all three rainfall factors involved.
    • Rainfall, Temperature, and Forage Dynamics Affect Nutritional Quality of Desert Mule Deer Forage

      Marshal, Jason P.; Krausman, Paul R.; Bleich, Vernon C. (Society for Range Management, 2005-07-01)
      Forage quality affects physiological condition, population dynamics, habitat use, and distribution of ungulates. We studied how rainfall, temperature, forage biomass, and forage growth are related to water content, crude protein (CP), and in vitro dry- matter digestibility (IVDMD) of some common forage species of desert mule deer (Odocoileus hemionus eremicus Mearns) in the Sonoran Desert, California. We established vegetation transects in desert washes to collect forage samples and to measure forage biomass, growth, rainfall, and temperature on a quarterly basis. Percent water and CP were positively associated with forage growth (P < 0.001) and with rainfall (P < 0.025). There were positive relationships between IVDMD and forage growth (P < 0.001), forage biomass (P < 0.001), and the combination of temperature and rainfall (P < 0.001). These findings suggest that the highest quality landscapes for deer are those with rapidly growing forage where forage water, CP, and IVDMD are greatest. With the quantified relationships between rainfall, temperature, and forage characteristics presented here, the nutritional constituents for deer forage can be predicted.  
    • Raintrap Performance on the Fishlake National Forest

      Dedrick, A. R. (Society for Range Management, 1973-01-01)
      Fifteen raintraps on the Fishlake National Forest in central Utah were observed over an 11-year period in an effort to evaluate field operation, maintenance requirements, and serviceability of raintrap systems. The raintraps generally functioned properly during the first 7 to 8 years. Some problems occurred during the latter part of the period. Five problem types were classified: (1) material failure-oxidation, ozone attack, and tearing; (2) mechanical damage-vermin attack and puncture by plants and animals; (3) snow accumulation which prevented water storage; (4) insufficient maintenance to catchment aprons, storage bags and ponds, watering troughs, and fences; and (5) improper design resulting from inaccurate estimate of or change in water requirements, poor site selection, and inadequate evaporation and precipitation data. Operational problems associated with the storage part of the raintrap system were more serious than those related to the catchment apron.
    • Rainwater harvesting for increasing livestock forage on arid rangelands of Pakistan

      Suleman, S.; Wood, M. K.; Shah, B. H.; Murray, L. (Society for Range Management, 1995-11-01)
      This study determined forage production and cover of several plant species resulting from the use of water harvesting catchments with catchment: cultivated area ratios of 1:1 and 1.25:1 and contributing aprons with 7, 10, and 15% slope gradients. Plots with 1.25:1 ratios produced more forage and had more cover than plots with 1:1 and 0:1 ratios. Plots with 7, 10, and 15% slope gradients had similar forage production and cover. Tuft planted plots produced more forage and cover than seeded plots. Ghorka (Elionurus hirsutus (Vahl) Munro), blue panicum (Panicum antidotale Retz.), and buffer (Cenchrus ciliaris L.) grasses produced similar forage and cover, which was higher than khev grass (Sporobolus helvolus (Trin.) Th. Dur. & Schinz) production and cover.
    • Ramifications of Vegetative Manipulation on Rangelands

      Byerly, T. C. (Society for Range Management, 1980-06-01)
    • Ranch Business Planning and Resource Monitoring for Rangeland Sustainability

      Maczko, Kristie A.; Tanaka, John A.; Smith, Michael; Garretson-Weibel, Cindy; Hamilton, Stanley F.; Mitchell, John E.; Fults, Gene; Stanley, Charles; Loper, Dick; Bryant, Larry D.; et al. (Society for Range Management, 2012-02-01)
      Aligning a rancher’s business plan goals with the capability of the ranch’s rangeland resources improves the viability and sustainability of family ranches. Strategically monitoring the condition of soil, water, vegetation, wildlife, livestock production, and economics helps inform business plan goals. Business planning and resource monitoring help keep ranchers on the land, support the well-being of rangeland-dependent communities, and conserve the rural way of life. To work toward this goal, the Sustainable Rangelands Roundtable (SRR), Wyoming Business Council (WBC), Wyoming State Grazing Board (WSGB), University of Wyoming Extension, Grazing Lands Conservation Initiative (GLCI), Samuel Roberts Noble Foundation, USDA Forest Service Rocky Mountain Research Station, Natural Resources Conservation Service, and several ranchers formed the SRR Ranch Sustainability Assessment Group. The working group focuses on implementing a monitoring framework for ecological, economic, and social sustainability within the context of ranchers’ business plans...
    • Ranch Decision-Making under Uncertainty—an Illustration

      Whitson, R. E. (Society for Range Management, 1975-07-01)
      Risk and uncertainty were explicitly included in a ranch decision model by the use of quadratic programming. Alternative ranch organizations are presented for a typical ranch firm in the Rolling Plains of Texas. These organizations illustrate the trade-offs between increasing net ranch income and the annual stability of income. To increase profits, the typical rancher was required to assume increasing amounts of risk. Incorporation of risk in the decision model improved understanding of the decision-making process of ranchers and the reasons why two similar ranchers could be "optimally" organized and operate with completely different ranch plans.
    • Ranch Management

      Oliver, H. (Society for Range Management, 1949-01-01)
    • Ranch Resource Differences Affecting Profitability of Crested Wheatgrass as a Spring Forage Source

      Spielman, K. A.; Shane, R. L. (Society for Range Management, 1985-07-01)
      A representative cow-calf ranch operation in Elko County, Nev., was modeled using a linear programming procedure to determine effects of selected ranch resource differences on profitability of seeding crested wheatgrass. Net present value (NPV) results suggest seeding crested wheatgrass as a spring forage can be a profitable investment if there are associated increases in calf weaning weights of 9.07 kg and increases in calving rates of 5 percentage points. Amount of meadow hayland, deeded range, and BLM forage available to the representative ranch were increased and decreased 50%. NPV's of the crested wheatgrass investment are greater for ranches with excess meadow hay and excess deeded range. NPV's are lower for ranches with limiting resources of meadow hayland, deeded range, and BLM forage.
    • Ranch Values and the Federal Grazing Fee

      Lambert, D. K. (Society for Range Management, 1987-09-01)
      Past analysis of the impacts of higher federal grazing fees on ranch values have been purely speculative due to the absence of observations on sales of Western cattle ranches under a wide range of fee levels. An income approach to ranch value determination is described here in which numerous parameters affecting value can be varied. Solutions attained under different grazing fees are capitalized into the net present value of a potential ranch investment. Substantial decreases in ranch revenues and ranch values can occur with large fee increases in cases where public land forage comprises a large share of a ranch's annual forage supply.