• Drummond's Goldenweed and Its Control with Herbicides

      Mayeux, H. S.; Scifres, C. J. (Society for Range Management, 1981-03-01)
      Several selective and nonselective foliar-active herbicides were applied alone and in 1:1 combinations as broadcast sprays in the spring for control of Drummond's goldenweed on the Coastal Prairie of Texas. Picloram at 0.56 kg/ha or picloram plus 2,4,5-T, glyphosate, or atrazine plus paraquat at 1.12 kg/ha consistently controlled the weed. Atrazine and 2,4-D, applied singly or in combination at 1.12 to 2.24 kg/ha total herbicide, effectively controlled Drummond's goldenweed only when soil-water content was high. Dicamba, like 2,4-D, was effective when applied in a "wet" year but not in a "dry" year. The effective herbicides controlled Drummond's goldenweed for at least 3 years. Although Drummond's goldenweed is morphologically similar to common goldenweed, it is apparently more susceptible to herbicides than its western counterpart.
    • Dry Matter Accumulation of Four Warm Season Grasses in the Nebraska Sandhills

      Gilbert, W. L.; Perry, L. J.; Stubbendieck, J. (Society for Range Management, 1979-01-01)
      Grass development and seasonal growth patterns are used in making range management decisions. Plant development and dry matter accumulation of four warm-season grasses were studied in the Nebraska Sandhills. Development of the grasses were slowed during 1974 due to low precipitation. Plant, leaf blade, and stem dry matter accumulation per shoot increased with successive harvests and were considerably greater both years for the tall grasses, sand bluestem [Andropogon hallii Hack.] and switchgrass [Panicum virgatum L.], than for the mid-grasses, little bluestem [Schizachyrium scoparium (Michx.) Nash.] and sand lovegrass [Eragrostis trichodes (Nutt.) Wood]. Leaf blade to stem ratios decreased with successive harvests for all grasses. Dry matter accumulation of the tall grasses was affected more by the low rainfall in 1974 than that of the mid-grasses. At the last harvest, decrease in stem dry matter accumulation was considerably greater than the decrease in leaf blade dry matter accumulation in 1974 as compared to 1973.
    • Dry Season Forage Selection by Alpaca (Lama pacos) in Southern Peru

      Bryant, F. C.; Farfan, R. D. (Society for Range Management, 1984-07-01)
      Two hundred eighty adult female alpacas (Lama pacos) and 200 tui alpacas (young alpacas 3-7 months of age) were grazed on a Festuca-Calamagrostis association at the South American Camelids Research Station, La Raya, Peru, during the dry season and early wet season of 1981 (June-December). Vegetation was sampled monthly during this period for herbage yield by species. Fecal material from both adult female alpaca and tui alpaca was collected monthly for microhistological analyses of food habits. Alpacas were primarily grazers rather than forb eaters during the dry season and early wet period of 1981. Forage classes consumed were different for adult and tui alpaca. Tui alpaca consumed more grass-like plants and forbs than adults during the driest months. Diet indices revealed the following as highly selected, common forage species: Eleocharis albibracteata, Poa. sp., Calamagrostis heterophylla, C. vicunarum, Alchemilla pinnata, Muhlenbergia fastigiata, and Carex spp. Highly selected, trace species were P. gymnantha, M. peruviana, Stipa brachiphylla, Ranunculus limoselloides, and Trifolium amabile. Festuca dolichophylla had been considered by range managers as highly preferred species overall. However, because it was the most abundant species (73% of the total forage yield), F. dolichophylla had a low selection index during the dry season. Alpacas consumed remarkable quantities of grass seeds (up to 20% of the diet) during the driest months of the year, apparently compensating for low quality forage.
    • Dry Season Regrowth of Six Forage Species Following Wildfire

      Falvey, J. L. (Society for Range Management, 1977-01-01)
      The regrowth of three introduced perennial grasses, buffelgrass, Pangolagrass, and Sabigrass; one native perennial grass, sehima; and two perennial legumes, Caribbean stylo and leucaena, after a dry season wildfire was studied in northern Australia. The native grass produced similar quantities of dry matter during the dry season but was of lower digestibility and crude protein content than all other species. Crude protein yield per hectare was highest for Sabigrass during the dry season. After the onset of the wet season the native grass produced significantly more dry matter and crude protein per hectare than all other species. Neither of the legumes provided large amounts of feed during the dry season. It is suggested that introduced grasses may be of greater value after a fire while native grasses may be superior after rains have begun.
    • Dry-weight-rank method assessment in heterogenous communities

      Dowhower, S. L.; Teague, W. R.; Ansley, R. J.; Pinchak, W. E. (Society for Range Management, 2001-01-01)
      Assessment of herbaceous standing crop in heterogeneous range plant communities requires large numbers of samples to account for inherent variability. The dry-weight-rank method (DWR) was developed to eliminate the need for clipping and sorting of herbage to determine relative proportions on a dry weight basis. The technique was assessed for applicability and accuracy in the mixed prairie of the Texas Rolling Plains. Much of the herbage within the communities investigated occurred in monospecific patches that resulted in only 15% of quadrats having 3 species ranked for which DWR was designed. Non-harvest methods of determining grass proportion by species were compared to harvested proportions in mesquite (Prosopis glandulosa Torr.) and redberry juniper (Juniperus pinchotii Sudw.) communities. Estimation methods evaluated were 1) harvest by species, 2) weight estimation by species, 3) DWR with quadrat weighting, 4) unweighted estimated proportion by species, and 5) unweighted DWR. Correlations of non-harvest to harvest proportions were improved with quadrat weighting. Weighting improved values more in the juniper than in the mesquite communities. Although cumulative ranking of DWR multipliers was necessary in 85% of sample quadrats, there was a high correlation (r2>0.995) between weight estimation and weighted DWR and between estimated proportion and unweighted DWR. This indicates that cumulative ranking with the original DWR multipliers was virtually the same as evaluator estimation. Analysis of variance indicated significant differences in non-harvest methods compared to harvesting. Quadrat weighting with DWR was necessary to draw the same statistical conclusions between means that harvest data provided. Ranks are easier to apply and more likely to be applied similarly by individual evaluators than estimated proportions. For sites with high standing crop variation and patchiness of species that require considerable use of cumulative ranking, DWR with quadrat weighting provides adequate determination of species proportions of biomass.
    • Drying and storage effects on germination of primed grass seeds

      Hardegree, S. P. (Society for Range Management, 1994-05-01)
      Cheatgrass (Bromus tectorum L.) has become the dominant species over large areas of rangeland in the Great Basin region of the western United States. Rapid germination at low temperature may contribute to the competitive success of cheatgrass in areas formerly dominated by native sagebrush and bunchgrass species. The objectives of this study were to determine whether seed priming could be used to stimulate low-temperature germination rate of native bunchgrass seeds and whether any priming effect was retained after drying and storage. Matric-priming was used to enhance germination rate response of 7 Great Basin native perennial grasses: thickspike wheatgrass [Agropyron dasystachyum (Hook.) Scribn.], bluebunch wheatgrass [Pseudoroegneria spicata (Pursh) Love], canby bluegrass (Poa canbyi Scribn.), sandberg bluegrass (Poa sandbergii Vasey.), bottlebrush squirreltail [Sitanion hystrix (Nutt.) J.G. Smith], sheep fescue (Festuca ovina L.), and basin wildrye [Leymus cinereus (Scribn. and Merr.) A. Love]. Priming enhanced germination rate of these species by 4 to 8 days at 10 degrees C. All species except canby bluegrass and basin wildrye could be induced to germinate as quickly as cheatgrass if they were not air-dried after priming. All species except canby bluegrass retained significant germination enhancement after 11 weeks of storage but only bluebunch wheatgrass maintained a germination rate comparable to cheatgrass when seeds were dried for storage.
    • Dryland Farming in Iran and Its Impact on Rangelands and Nomadic Life

      Koocheki, A. (Society for Range Management, 1986-12-01)
    • Drylot All-Concentrate Feeding—An Approach to Flexible Ranching

      Thomas, G. W.; Durham, R. M. (Society for Range Management, 1964-07-01)
    • Drylot Wintering of Range Cows—Adaptation to the Ranching Operation

      Schuster, J. L.; Albin, R. C. (Society for Range Management, 1966-09-01)
      Pregnant range beef cows adjusted to drylotting on all-concentrate grain sorghum rations and then readjusted to native range. Weight changes and reproductive performance on a limited all-concentrate ration compared favorably with commonly used methods of wintering the cow herd. Costs for two drylot methods were higher than for two pasturage methods.
    • "Duck Stamp" Dollars Reserve Native Prairie Tracts

      Higgins, Kenneth F. (Society for Range Management, 1981-10-01)
    • Duluth—An Island Seaport

      Wright, Donald C. (Society for Range Management, 1988-06-01)
    • Dung Deposition, Breakdown and Grazing Behavior of Beef Cattle at Two Seasons in a Tropical Grassland Ecosystem

      Omaliko, C. P. E. (Society for Range Management, 1981-09-01)
      The effects of seasons on size, number and area of the dung deposited on a grazed paddock were examined. Rate of dung breakdown, herbage fouling, and rejection were also investigated. Significant seasonal differences were found in number, size, area of dung and in proportion of paddock fouled per grazing such that these values were higher in wet than in dry season. A higher breakdown rate was obtained in the dry season when the termites were the main degradation agents than in the wet season when the dung was degraded mainly by the copriphilous fungi. The herd rejected the fouled herbage for a longer period during wet season than during the dry season. Two breakdown patterns for the dry season (depending on the presence of termites in the ecosystem) were suggested. Herbage rejection was discussed in relation to animal production and range improvement.
    • Duration of Seeded Stands on Terraced Mountain Lands, Davis County, Utah

      Hull, A. C. (Society for Range Management, 1973-03-01)
      Thirty-seven species were seeded experimentally in northern Utah on 14 areas on depleted and terraced mountainous rangelands from 1936 to 1939. Seventeen species had fair to excellent 3-year-old stands. Most stands decreased; and in 1971 only smooth brome, tall oatgrass, intermediate wheatgrass, and red fescue have fair to excellent stands. Smooth brome spread slowly by rhizomes and usually formed a dense sod. Tall oatgrass spread by seed with a poor to good stand on ten times the original seeded area. Intermediate wheatgrass has spread by rhizomes and forms a good stand on the large plot where it was seeded in 1941. Red fescue did well on favorable sites but was not tested under typical conditions. Native grasses, forbs, shrubs, and trees have reinvaded the seeded areas.
    • Dutchwoman Butte Revisted

      Sprinkle, Jim; Holder, Mick; Erickson, Chas; Medina, Al; Robinett, Dan; Ruyle, George; Maynard, Jim; Tuttle, Sabrina; Hays, John; Meyer, Walt; et al. (Society for Range Management, 2007-12-01)
    • Dutchwoman Butte: A Relict Grassland in Central Arizona

      Ambos, Norman; Robertson, George; Douglas, Jason (Society for Range Management, 2000-04-01)
    • Dynamics of Blue Grama within a Shortgrass Ecosystem

      Uresk, D. W.; Sims, P. L.; Jameson, D. A. (Society for Range Management, 1975-05-01)
      The dynamics of standing crop for live, dead, and litter compartments of blue grama were studied for 2 years to formulate equations useful for predicting growth rates over 2-week intervals. During the period of rapid vegetative growth, 54% of the variation in rates of changes for live herbage was accounted for by the amount of live herbage present at a given time. During the declining period, the amount of live herbage, leaf moisture, and air temperature accounted for 58% of the variation in net changes. The transfer rate from live to dead herbage was 0.22% of the live herbage per day during the growing season, while litter accumulated from the dead herbage at a rate of 0.31% per day. This transfer rate became 0.086% per day during the non-growing season. Litter decomposed during the growing season at a rate of 0.35% per day.
    • Dynamics of Dormancy-Status Subpopulations of Indian Ricegrass Seed Held in Dry Storage

      Jones, T. A. (Society for Range Management, 2009-05-01)
      Germination of Indian ricegrass (Achnatherum hymenoides [Roem. Schult] Barkworth), a rangeland species native to western North America, is limited by persistent seed dormancy. We previously identified high-dormancy (HD) and low-dormancy (LD) genotypes from within the genetically heterogeneous cultivar Rimrock. Seed was produced in 2000 and 2001 in a common garden, stored in paper-can containers at room temperature, and tested every 3 mo with and without prechill through 2005. In 2005, tetrazolium viability of all four lots was 99%, reflective of this species’ extensive seed longevity. Over this time period, germination of nonprechilled seed increased from 1% to 53% for HD and from 15% to 79% for LD, whereas corresponding increases for prechilled seed were from 8% to 56% for HD and from 61% to 76% for LD. At first, the great majority of seeds of HD (99%) and LD (86%) were dormant, but this majority was overwhelmingly prechill nonresponsive for HD (92%) compared to roughly equal portions of prechill-nonresponsive (39%) and prechill-responsive (46%) seed for LD. At the end of the trial, most seeds of both HD (53%) and LD (79%) were nondormant, but more prechill-nonresponsive seeds were present in HD (44%) than LD (24%). Over the course of the study, the prechill-nonresponsive subpopulation declined more for HD (by 32%), the prechill-responsive subpopulation declined more for LD (by 45%), and overall dormancy (sum of the two subpopulations) declined more for HD (by 13%). The prechill-responsive subpopulation was depleted more quickly than the prechill-nonresponsive subpopulation for both genotypes. Both HD and LD genotypes were responsive to room-temperature storage without loss of viability over a 4-5-yr period. These data highlight the utility of long-term storage as a technique to improve germinability, and consequently establishment, success of Indian ricegrass. 
    • Dynamics of shrub die-off in a salt desert plant community

      Ewing, K.; Dobrowolski, J. P. (Society for Range Management, 1992-03-01)
      Mortality of shadscale (Atriplex confertifolia [Torr. & Frem.] Wats.) was severe in Great Basin valley bottoms between 1983 and 1988. Puddle Valley, Utah, just west of the Great Salt Lake, typifies areas of extensive shrub loss in which density decreased from over 12,000 ha-1 to less than 200 ha-1. We analyzed vegetation along a radial transect established in the bottom of Puddle Valley in 1987. Mortality was greatest at the lowest elevations where shrubs were initially most dense. These sites occurred where soil moisture, fine-textured soils, and bulk density were greatest of all sites evaluated. Soil was most saline at the margins of the valley bottom. Higher densities of live shadscale occurred where slopes are greater, soil is more droughty, and soil moisture was lower during the 3 years of data collection. The die-off "front" continued about 5 km to the west of the valley center in 1989. Refugia of live shadscale populations were found where soil salinities were higher. Population dynamics of annuals, including summer-cypress (Kochia scoparia [L.] Schrader), cheatgrass (Bromus tectorum L.), and halogeton (Halogeton glomeratus [Bieb.] C.A. Mey.) were highly variable between 1987 and 1989.
    • Dynamics of the Root System of Blue Grama

      Ares, J. (Society for Range Management, 1976-05-01)
      Field experiments were conducted to determine dynamics of the root system of blue grama (Bouteloua gracilis) during the 1973 growing season at the US/IBP Pawnee Site in northern Colorado. Differentiation and growth of blue grama roots were recorded in field conditions by means of windows in excavations. Roots began to grow and differentiate a short time before leaf growth was apparent. Desiccation of soil in the mid-growing season resulted in death and subsequent decomposition of 30% to 60% of the newly formed roots. Massive root growth occurred when soil water potential was high near the end of the growing season. Roots were separated into morphological categories by microscopic analysis of soil samples on May 15, near the beginning of the growing season, and on August 9, near the end of it. Young nonsuberized roots, so important in water absorption, were concentrated in regions of the soil profile where soil water potential was high. An empirical model of root growth and development in B. gracilis is derived from the data.
    • Dynamics of vegetation along and adjacent to an ephemeral channel

      Smith, M. A.; Dodd, J. L.; Skinner, Q. D.; Rodgers, J. D. (Society for Range Management, 1993-01-01)
      Ephemeral channels may be greater contributors to nonpoint sediment loads than perennial channels because of their abundance and lower vegetative cover. This study examines above- and belowground standing crop responses of selected vegetation classes and density of shrubs to grazing use and yearly weather variation along an ephemeral stream in northcentral Wyoming. Aboveground biomass standing crop was determined yearly in channel, floodplain, and upland habitats in ungrazed and grazed pastures during the 4-year study. Belowground biomass and shrub densities were determined yearly in the channel habitat only. Perennial grass standing crop in channels did not respond to grazing but decreased up to 73% with decreases in frequency and amount of precipitation. In floodplains, perennial grasses were not responsive to grazing; annual grasses were twice as abundant in grazed pastures. Vegetation standing crop in uplands was not influenced by grazing. Over the study period in all pastures, standing crop of blue grama (Bouteloua gracilis (H.B.K.) Lag. ex Griffiths) declined 4 fold while cool-season grasses increased 5 fold. Shrub density did not increase as much in grazed as in ungrazed pastures. Root biomass of the channel decreased 23% in years with less precipitation but was greater by 24% on concave than convex bank types. Location on channels influenced root biomass but grazing did not. Lack of general negative grazing influences on vegetation suggest short periods (10 days) of grazing as used in this study represent a sustainable management alternative for grazing in the cold desert.