• Technical Notes: Direct effect of parasitism by Dinarmus acutus Thomson on seed predation by Acanthoscelides perforatus (Horn) in Canada milkvetch

      Boe, A.; McDaniel, B.; Robbins, K. (Society for Range Management, 1989-11-01)
      Canada milk-vetch (Astragalus canadensis L.) is a widespread North American legume considered to be good forage in some regions but potentially dangerous to livestock when it contains high levels of 3-nitropropionic acid. Larvae of the seed predator Acanthoscelides perforatus (Horn) (Coleoptera:Bruchidae) occurred in 77% of the mature pods from 10 genotypes of the legume growing in a nursery at Brookings, S. Dak., in autumn 1987. Dinarmus acutus Thomson (Hymenoptera: Pteromalidae) parasitized 48% of the A. perforatus larvae and reduced numbers of seeds consumed by A. perforatus larvae by 23%. This study identified D. acutus as a parasitoid of A. perforatus and indicated parasitoids may play an important role in recruitment of native legumes.
    • Technical Notes: Double sampling revisited

      Reich, R. M.; Bonham, C. D.; Remington, K. K. (Society for Range Management, 1993-01-01)
      The decision to use double sampling with a regression or ratio estimator is not a simple task. This study was conducted to determine whether a ratio or regression estimator should be used to estimate aboveground biomass of stands dominated by blue grama (Bouteloua gracilis (H.B.K.) Lag ex Steud.) in eastern Colorado. One hundred 0.25-m-1 circular plots were systematically located in a homogeneous stand of blue grama, and on each plot biomass was estimated visually and then clipped. Three methods (classical, jackknife, and bootstrap) of estimating the variance for double sampling with regression and ratio estimator were compared in a simulation study using sample sizes 10, 20, 30, 40, and 50 clipped plots. The ratio estimator consistently had smaller bias and should be used for estimating average clipped weight of blue grama. For n = 10 clipped plots, the jackknife variance estimator is recommended for constructing confidence intervals. For n greater than or equal to 20 clipped plots, the classical variance estimate should be used to obtain reliable estimates of the population variance and in estimating confidence intervals.
    • Technical Notes: Evaluation of dietary preference with a multiple latin square design

      Borman, M. M.; Adams, D. C.; Knapp, B. W.; Haferkamp, M. R. (Society for Range Management, 1991-05-01)
      A sequential multiple latin square experimental design was evaluated as a tool for establishing dietary preference rankings. Dietary preference of 4 grasses was determined by a series of four 4 X 4 latin squares where rows were 4 days within a pen, columns were 4 locations of a grass within a pen, and treatments were 4 grasses. Each square (i.e., pen) utilized 1 lamb. Following the completion of trial 1, the most preferred grass was withdrawn and the 3 remaining grasses were further studied with a series of four 3 X 3 latin squares. This procedure was found to be a resource efficient and effective tool for preference ranking.
    • Technical Notes: Evaluation of the Dry-Weight-Rank Method for Determining Species Composition in Tallgrass Prairie

      Gillen, R. L.; Smith, E. L. (Society for Range Management, 1986-05-01)
      The dry-weight-rank (DWR) method for determining species composition of tallgrass prairie vegetation was compared to hand clipping. Species composition estimates for the 2 methods were similar in 3 of 4 trials when true ranking and previously published multipliers were used. Weighting the DWR estimates by plot total weight did not consistently improve the accuracy of the method. Observer errors reduced the accuracy of DWR, emphasizing the need for observer training. DWR estimates were generally less precise than hand clipped estimates for a given sample size but the speed of DWR would allow more samples to be taken resulting in more precise estimates in practice.
    • Technical Notes: Germination of 2 legumes in leachate from introduced grasses

      Fulbright, N.; Fulbright, T. E. (Society for Range Management, 1990-09-01)
      Kleberg bluestem [Dichanthium annulatum (Forsk.) Staph and buffelgrass (Cenchrus ciIiaris L.) may produce pbytotoxic chemicals that inhibit germination and growth of legumes planted in seeding mixtures with grasses. We determined the effects of leachate from these introduced grasses on seed germination of Illinois bundleflower [Desmanthus illinoensis (Michx.) MacM.] and partridge pea (Cassia fasciculata Michx.). Percent germination of Illinois bundleflower seeds on substrata moistened with Kleberg bluestem root or buffelgrass leaf leachate was lower than that of seeds placed on substrata moistened with distilled water. Buffelgrass root Ieachate reduced germination of partridge pea more than did root leachate from Kleberg bluestem or leaf leachate from Kleberg bluestem or buffelgrass. Results of these laboratory experiments indicate that field studies are warranted to determine the effects of buffelgrass on establishment of partridge pea and Illinois bundleflower in order to help land managers select the optimum combination of species for rangeland seeding.
    • Technical Notes: Reference Unit-based Estimates of Winterfat Browse Weights

      Cabral, D. R.; West, N. E. (Society for Range Management, 1986-03-01)
      Precise and accurate plant weight data are important to range managers, but difficult and expensive to obtain. Indirect and nondestructive estimates are especially desirable where vegetation is sparse and slow-growing on permanent plots. A new indirect, nondestructive approach developed in Australia, the reference unit method, was quantitatively related to clipped weights of winterfat (Ceratoides lanata) browse in Curlew Valley, Utah. The reference unit method was quite precise, accurate, and efficient in predicting browse weights even though size and form of the shrubs differed greatly. The only major disadvantage was mental fatigue created by the requirement of greater sustained concentration.
    • Technical Notes: Secar bluebunch wheatgrass as a competitor to medusahead

      Goebel, C. J.; Tazi, M.; Harris, G. A. (Society for Range Management, 1988-01-01)
      A search continues for native perennial range grasses which will compete successfully with introducted annual grasses. Secar blue-bunch wheatgrass (Agropyron spicatum) is a recently released cultivar selected for seedling vigor. Medusahead (Taeniatherum asperum) seeds germinated in about one third the time, were less inhibited by cold temperatures typical of range conditions, and seedlings grew more than twice as fast as Secar in a 30-day trial. Indications are that even this new cultivar will not compete successfully with vigorous medusahead seedlings without initial weed control.
    • Technical Notes: Separating leaves from browse for use in nutritional studies with herbivores

      Gallagher, J. F.; Barnes, T. G.; Varner, L. W. (Society for Range Management, 1988-11-01)
      A technique has been developed that facilitates removal of green leafy material from stems of shrub species using a thresher. Use of this technique makes possible the rapid removal of leaves from woody species that would otherwise require excessive hand labor.
    • Technical Notes: Survival Analysis of Single and Twin Lambs

      Scrivner, J. H.; Dally, M. R.; Howard, W. E. (Society for Range Management, 1987-03-01)
      We illustrate the use of life tables and survival analysis for evaluating data on livestock losses. The techniques are used to compare the rate of coyote (Canis latrans) predation on single and twin lambs. Based on the number of lambs known to have been killed by predators, the survivorship of single and twin lambs was not significantly different (P>0.05) for any year of the study. Survival functions which can be generated and used to evaluate data on livestock losses include the cumulative proportion of livestock surviving at the end of an interval, probability density, and hazard rate.
    • Technical Notes: The effect of light on adventitious root formation in blue grama

      Roohi, R.; Jameson, D. A.; Nemati, N. (Society for Range Management, 1991-03-01)
      Formation of adventitious roots in blue grama seedlings requires that the node between the subcoleoptile and the coleoptile be exposed to light at the 3-leaf or later stages of development. Thus, adventitious root formation will occur only at or near the soil surface. With continuous light, the subcoleoptile approximated zero length, but for those developed in darkness the usual length was about 1 cm. Under usual range conditions, the time between germination and the 3-leaf stage of development is such that it is rare that both of these events will occur with moist soil conditions, and seedling survival will be infrequent.
    • Technical Notes: The grass spikelet formula: an aid in teaching and identification

      Allred, K. W.; Columbus, J. T. (Society for Range Management, 1988-07-01)
      The structure and arrangement of the grass spikelet may be summarized by use of a spikelet formula. The parts of the formula are stacked vertically to correspond to the parts of the grass spikelet. Nerves and numbers of parts are indicated by super- and subscripts. Spikelet formulae may be a useful teaching tool, as well as a convenient field notation.
    • Technical Notes: The relationship of stocking intensity and stocking pressure to other stocking variables

      Scarnecchia, D. L. (Society for Range Management, 1985-11-01)
      Stocking intensity and stocking pressure have been defined and used as technical stocking variables describing animals on pasture. Relationships between these variables and stocking variables such as stocking density and stocking rate are discussed. One conclusion is that stocking intensity and stocking pressure are not informationally unique variables, but are equivalent to stocking variables defined in other work. Retention of the terms stocking intensity and stocking pressure is recommended for nontechnical use in describing livestock grazing.
    • Technical Service Providers: What's the Potential?

      Leahy, Stephen (Society for Range Management, 2003-06-01)
    • Technique to Separate Grazing Cattle into Groups for Feeding

      Karn, J. F.; Lorenz, R. J. (Society for Range Management, 1984-11-01)
      A training procedure is described which was used to separate a group of cattle grazing the same pasture into smaller groups to facilitate supplementation. The procedure was successfully used to make 3 separations and probably could be used for 1 or 2 more. It appears to be a useful alternative to maintaining supplementation groups on separate pastures.
    • Techniques for computer-assisted mapping of rangeland change

      Yool, S. R.; Makaio, M. J.; Watts, J. M. (Society for Range Management, 1997-05-01)
      Management of grasslands subject to replacement by woody species requires an understanding of the scales and patterns of change and how to detect and express them. We used the Jornada del Muerto Basin of southern New Mexico as a case study, testing the suitability of Landsat Multi-Spectral Scanner (MSS) data for detecting vegetation changes. Cycles of drought and heavy grazing have apparently changed the once extensive grasslands of the upland Jornada and surrounding areas gradually into a patchwork of shrublands and relict grasslands. Integrated remote sensing and geographic information system (GIS) techniques can facilitate automated detection of these rangeland changes. A GIS was used to store and process two 4-band, co-registered multi-temporal Landsat MSS scenes collected in July 1983 and August 1992. Scene-to-scene radiometric calibration was performed using a regression technique. The data were then evaluated for changes 3 different ways using algorithms based on differences between the 'red' (chlorophyll absorption) bands for the 2 scenes; the Euclidean distances between the 'red' and 'near-infrared' bands for the 2 scenes; and a standardized principal components analysis using all 8 MSS bands. A threshold of 3 standard deviations above the mean was applied to each of the 3 resulting 'change' images to represent areas of extreme change. Correlations among these images ranged between 0.83 and 0.95. We conclude these techniques can identify successfully the patterns and extent of extreme change, and thus have potential value for management of our rangelands resources.
    • Techniques in Studying Competition Between Big Game and Livestock

      Julander, O. (Society for Range Management, 1958-01-01)
    • Techniques Useful in Range Research

      Heady, H. F. (Society for Range Management, 1955-05-01)
    • Technology for Reversing Desertification

      Anderson, Ray (Society for Range Management, 1981-04-01)
    • Technology Transfer: Who Uses Information About Rangelands and Why?

      Svejcar, Tony; Brown, Joel; Connor, Mike (Society for Range Management, 1995-06-01)
    • Telling It Like It Is

      Maltsberger, Bill (Society for Range Management, 1984-06-01)