• Genetic variability of Mg, Ca, and K in crested wheatgrass

      Mayland, H. F.; Asay, K. H. (Society for Range Management, 1989-03-01)
      Increasing available Mg in crested wheatgrass (Agropyron spp.) could reduce the incidence of grass tetany (hypomagnesemia) in ruminants grazing this forage. Raising the Mg levels might be done through genetic processes if enough variation in ion concentration existed in the Agropyrons. The purpose of this study was to determine the genetic variation in Mg, Ca, and K concentrations in 2 crested wheatgrass populations. Parent plants were vegetatively propagated to provide 6 replicates each of 12 clones of crested wheatgrass (A. desertorum) and 16 F3 clones of colchicine-induced tetraploid A. cristatum X natural tetraploid A. desertorum. Each plant was selected on a basis of seedling and mature plant vigor, forage, and seed yield, leafiness, resistance to pests, and response to environmental stress. The 2 populations were grown in separate, space-planted nurseries at Logan, Utah. Herbage was harvested at the pre-boot and early flowering stage in each of 2 years. Magnesium and Ca were determined by atomic absorption and K by flame emission. A reduced tetany potential (RTP) index for each clone was calculated as the sum of normalized Mg and (Ca+Mg)/K values. Significant (P < 0.01) differences for all traits were detected among clones in each population. All traits, except K and RTP, were closely correlated. Broad-sense heritability values for most traits ranged from 0.61 to 0.84. Enough genotypic variation existed in both populations to warrant breeding lines with higher concentrations of Mg and larger RTP values. Such changes could reduce the incidence of grass tetany in livestock grazing crested wheatgrass.
    • Genetic variances for dry matter yield, nitrogen content, and nitrogen yield in crested wheatgrass-alfalfa mixtures

      Asay, K. H.; Mayland, H. F. (Society for Range Management, 1991-09-01)
      Since its introduction from Asia in the early 1900s, crested wheatgrass [Agropyron cristatum (L.)Gaertner, A. desertorum (Fisch. ex Link) Schultes et al.] has had a major impact on the improvement of western rangelands of North America. Most of the early seedings with this cool-season grass were made as monocultures. Present and projected use of rangelands, however, prescribe that future crested wheatgrass cultivars have the genetic potential to be an effective component in a species complex including other grasses, shrubs, and forbs. The present study was conducted to evaluate the effect of associated alfalfa (Medicago sativa L.) on the performance and genetic variability in a 50-clone sample of a tetraploid crested wheatgrass breeding population. Significant (P < 0.05) differences were found among the clonal lines for dry matter (DM) yield, nitrogen (N), and N yield. Opportunities for genetic improvement, as indicated by the magnitude of the genetic variation for these characters, was significantly increased when the grasses were grown in association with alfalfa. Significant (P < 0.01) and positive correlations of clonal means between stand types indicated that differences among the clonal lines in DM yield, N content, and N yield were relatively consistent when grown with or without alfalfa. These results indicate that initial screening could be effectively done in tetraploid crested wheatgrass in the presence or absence of alfalfa. Final evaluation of breeding lines and experimental strains, however, should be done with alfalfa if the object is to develop cultivars to be grown in combination with that species.
    • Genetic variation and inheritance characteristics for carbon isotope discrimination in alfalfa

      Johnson, D. A.; Rumbaugh, M. D. (Society for Range Management, 1995-03-01)
      The negative correlation between carbon isotope discrimination and water-use efficiency in C3 species, including alfalfa (Medicago sativa L.), suggests that carbon isotope discrimination that might be useful in the selection of alfalfa cultivars that use water more efficiently. We initiated field experiments with alfalfa in northern Utah to determine genetic variation for carbon isotope discrimination within representative breeding populations, the effect of drought on carbon isotope discrimination, magnitudes of heritability for carbon isotope discimination, genetic regulation of carbon isotope discrimination, and how carbon isotope discrimination differs among plant parts. In an experiment conducted under a rainout shelter facility equipped with a line-source sprinkler system, genetic variability for carbon isotope discrimination was not detected in 15 clones each from the NC-83-1 germplasm and 'Spredor 2' cultivar. In another experiment with 25 clones from the NC-83-1 germplasm, there was significant (P < 0.01) genetic variation for carbon isotope discrimination with a range of 1.6 per thousand, and broad-sense heritabilities exceeded 0.80. In a field trial with 78 cultivars and elite breeding lines, significant genetic variation for carbon isotope discrimination was observed, although the range for carbon isotope discrimination was only 0.8 per thousand. We also detected significant genetic variation for carbon isotope discrimination in a diallel experiment with 196 crosses from 14 parent clones from NC-83-1. Furthermore, general combining ability was significant, but specific combining ability and reciprocal effects were not, indicating that standard breeding techniques could be used to alter carbon isotope discrimination response in alfalfa. Plant parts differed significantly for carbon isotope discrimination with stems having the lowest value (18.7 per thousand) followed by the entire shoot (19.0 per thousand), upper leaves (19.4 per thousand), and bottom leaves (20.2 per thouand). The lack of significant statistical interactions among plant parts suggested that any plant part could be sampled to determine carbon isotope discrimination. The results from these experiments indicated that promise exists for using carbon isotope discrimination to improve water-use efficiency in alfalfa; however, use of more diverse germplasm may be necessary to expand opportunities for selection in North American alfalfa germplasm.
    • Genotype and planting depth effects on seedling vigor in sericea lespedeza

      Qiu, J.; Mosjidis, J. A. (Society for Range Management, 1993-07-01)
      Sericea lespedeza [Lespedeza cuneata (Dumont de Courset) G. Don.] is a small-seeded forage legume that can improve forage quality and nitrogen content of interseeded pasturelands. Poor seedling vigor has caused interseeding failure. This study was conducted to determine the effects of genotype, planting depth, and their interaction on seeding vigor of services lespedeza in the field, and to determine if seedling traits measured in a growth chamber can be used to predict seedling growth in the field. Substantial variability was found among 54 sericea lespedeza genotypes for traits that can be used in a breeding program to improve seedling vigor. All seedling traits were correlated with each other, indicating a high proportionality existed among plant parts. Thus, any of the seedling traits measured could be used to represent seedling vigor. Genotypes 73-162-16, AU L2, AU L13, and 'Serala 76' outperformed other genotypes for most seedling traits under field and growth chamber conditions. Planting to a depth of 3 cm did not reduce seedling vigor, and therefore, may be recommended when there is insufficient moisture in the upper layer of sandy loam soils at planting. Although measurements taken in the growth chamber did not reliably predict field performance, information gathered in the growth chamber provides a good means of increasing the frequency of superior plants to be tested in the field.
    • Geographic Distribution and Factors Affecting the Distribution of Salt Desert Shrubs in the United States

      Branson, F. A.; Miller, R. F.; McQueen, I. S. (Society for Range Management, 1967-09-01)
      Four previously published classifications of intermountain shrub vegetation and a new classification based on maximum salt tolerances and water relationships are presented. Maps show that the geographic range of salt desert shrub species far exceeds the distribution of mappable communities in which these shrubs are dominants. Species differ in their capacity to tolerate soil osmotic stress, but variable results from measurements of osmotic stress in 20 different plant communities indicate that additional factors must be important in determining species present in different habitats. Data obtained by the use of a new method of measuring total soil moisture stress in field samples show that the capacity of different species to remove soil moisture to different maximum stresses appears to determine the kinds of plants that occupy different habitats. Total soil moisture stresses for 14 plant communities sampled ranged from 19 to more than 90 bars.
    • Geographic Information System as an Aid to Rangeland Management in Kenya

      Herlocker, D. J.; Shaabani, S. B.; Thurow, T. L. (Society for Range Management, 1994-12-01)
    • Geographical Information System Technology for Developing a Conservation Plan for the Northern Cheyenne Tribe in Montana

      Noggles, R. Sue; Harrison, William D.; Schwagler, Rocklin R.; Johnson, Terry W. (Society for Range Management, 1998-06-01)
    • Geologic grazing refuges and grassland diversity: A shortgrass steppe study

      Milchunas, Daniel G.; Noy-Meir, Imanuel (Society for Range Management, 2004-03-01)
      Geologically isolated, natural grazing refuges that have never been grazed by domestic livestock can be foci of diversity for rare species. This study compared refuges protected from grazing by ravines to adjacent grazed sites in an uncommon grassland type in eastern Colorado. We also tested whether differences between refuge and grazed sites were due to protection from grazing versus abiotic conditions, based on temporary caging of little bluestem plants (Schizachyrium scoparium [Michaux] Nash). Regionally rare species were not exclusive to refuges, but occurred also on adjacent grazed sites. However, refuges showed greater species richness, as well as greater abundance of several tall stature species that are uncommon in the surrounding shortgrass steppe. Temporary protection of little bluestem plants in grazed sites resulted in significant changes in growth and reproductive output, in the direction of refuge plants. Though this geological refuge did not manifest an exclusive set of rare species as reported from other systems, it does preserve strong source populations of uncommon species that are sensitive to grazing and thereby contributes to regional grassland diversity.
    • Geology and Mines of Idaho

      Alt, Dave (Society for Range Management, 1999-10-01)
    • Geology and Soils of Grassland Ranges, Kamloops, British Columbia

      van Ryswyk, A. L.; McLean, A. (Society for Range Management, 1989-06-01)
    • George Elmo Glendening—An "Unknown Star" in Southwestern Range Research

      Cox, Jerry R.; Johnsen, Thomas N.; Morton, Howard L. (Society for Range Management, 1987-08-01)
    • Geospatial Assessment of Grazing Regime Shifts and Sociopolitical Changes in a Mongolian Rangeland

      Sankey, Temuulen Tsagaan; Sankey, Joel B.; Weber, Keith T; Montagne, Cliff (Society for Range Management, 2009-11-01)
      Drastic changes have occurred in Mongolia’s grazing land management over the last two decades, but their effects on rangelands are ambiguous. Temporal trends in Mongolia’s rangeland condition have not been well documented relative to the effects of long-term management changes. This study examined changes in grazing land use and rangeland biomass associated with the transition from the socialist collective to the current management systems in the Tsahiriin tal area of northern Mongolia. Grazing lands in Tsahiriin tal that were formerly managed by the socialist collective are now used by numerous nomadic households with their privately owned herds, although the lands remain publicly owned. Grazing pressure has more than tripled and herd distribution has changed from a few spatially clustered large herds of sheep to numerous smaller herds of multiple species. Landsat image- derived normalized-difference vegetation index estimates suggest that rangeland biomass significantly decreased (P < 0.001) from the collective to the postcollective periods. The observed decrease was significantly correlated with changes in the grazing management system and increased stocking density (P < 0.001), even when potential climate-induced changes were considered. Furthermore, field- and Satellite Pour l’Observation de la Terre imagery-based rangeland assessments in 2007 and 2008 indicate that current rangeland biomass is low. Spatial pattern analyses show that the low biomass is uniform throughout the study site. The observed decrease in rangeland biomass might be further accelerated if current grazing land use continues with no formal rangeland management institution or organized, well-structured efforts by the local herding households. 
    • Germinability and Seedling Vigor of Haloxylon salicornicum as Affected by Storage and Seed Size

      Clor, M. A.; Al-Ani, T. A.; Charchafchy, F. (Society for Range Management, 1976-01-01)
      When newly collected in early spring, seeds of Haloxylon salicornicum (Moq.) Bge., an important range shrub in Iraq, attained 100% germination within 24 hours. As the summer months followed, a considerable loss of viability was observed in seeds stored at room temperature. By December, only about 50% of the seeds germinated. The seeds maintained their full germination capacity, with little difference between large and small size seeds when stored at 5°C. Under room temperature, the small size seeds lost their viability faster than the larger ones. Seeds stored at 5°C produced more vigorous seedlings than those stored at room temperature. Large seeds produced more vigorous seedlings than small seeds, regardless of method of storage. Seeds that germinated rapidly produced more vigorous seedlings than those that germinated slowly.
    • Germination and Emergence of Different Age Seeds of Six Grasses

      Shaidaee, G.; Dahl, B. E.; Hansen, R. M. (Society for Range Management, 1969-07-01)
      Different aged seeds of six grass varieties were tested for percentage laboratory germination and percentage field emergence. Best age of seed for planting differed greatly among the varieties and the results from laboratory and field tests were not always consistent. One-year-old seeds of sand bluestem, blue grama and A-6606 switchgrass; two-year-old side-oats grama and yellow indiangrass; and seven-year-old Grenville switchgrass seeds had emerged best at the end of the field test. Except for sandhill bluestem, seeds two years and older emerged faster, a factor that may be important in successful field establishment of seeded grasses.
    • Germination and Longevity of Velvet Mesquite Seed in Soil

      Tschirley, F. H.; Martin, S. C. (Society for Range Management, 1960-03-01)
    • Germination and root growth of 4 osmoconditioned cool-season grasses

      Mueller, D. M. (Society for Range Management, 1996-03-01)
      Establishment of grass species used in range reseeding should improve if germination time can be decreased. Osmotically controlling the hydration of seed so that germination processes proceed other than radicle emergence (osmoconditioning) can decrease germination time of many plant species. Growth chamber esperiments were conducted to evaluate effects of osmoconditioning at -1.5, -2.0, and -2.5 hlpa for 4,8,12,16, and 20 days on germination and root growth of ‘Flintlock’ western wheatgrass (Pascopyrum smithii (Rydb.) A. Löve) and ‘Vinall’ Russian wildrye (Psathyrostuchys juncea (Fischer) Nevski) and at -2.0, -2.5, and -3.0 hWa for 4, 8, 12, 16, and 20 days on ‘Nordan’ Crested wheatgrass (Agropyron desertorum (L.) Gaertn.) and ‘Tegmar’ intermediate wheatgrass (Agropyron intermedium (Host) Beauv.). A second study looked at germination time of seed from the same species conditioned at osmotic potentials and durations producing the shortest time to 50% germination (optimum conditioning) and air dried for 0, 1, or 7 days. Conditioned seed of Russian wildrye and western wheatgrass germinated 2 to 4 days faster, respectively than untreated seed. Optimum conditioning of seed from all 4 species produced seedlings with roots 20 to 67% shorter 4 days after germination than seedlings from untreated seed. Conditioned western wheatgrass seed continued to germinate faster than untreated seed after being air dried for 7 days. Slow root growth from conditioned seed may negate any benefits derived from rapid germination.
    • Germination and Seedling Emergence of Three Semiarid Western North American Legumes

      Bushman, B. S.; Johnson, D. A.; Connors, K. J.; Jones, T. A. (Society for Range Management, 2015-11)
      Few seed sources of North American forbs are available for revegetation/restoration of degraded western rangelands adapted to annual precipitation zones less than 300 mm, and those that are available are mainly wildland collected. The amount of time and resources necessary to make wildland collections in quantity results in high seed prices and variable seed quality, such that forbs have been under-represented in rangeland seeding mixes. We have previously identified western prairie clover (Dalea ornata Douglas ex Hook.), Searls' prairie clover (Dalea searlsiae A. Gray), and basalt milkvetch (Astragalus filipes Torr. ex A. Gray) as native species adapted to low precipitation zones in the western United States for which field-grown seed production would potentially reduce seed costs and increase availability. A series of glasshouse experiments were conducted to determine the effects of scarification, planting depth, and soil composition on germination and seedling emergence of these species. All three species produce hard seeds, and scarification was necessary to increase germination and seedling emergence. Compared with a 6-mm planting depth, a planting depth of 19 mm retarded the rate of emergence for all species but only reduced the total seedling emergence for basalt milkvetch. With seed scarification in sandy soils, prairie clover seedling emergence exceeded 80% while basalt milkvetch was less than 10%. With seed scarification in soils with higher clay content, prairie clover total seedling emergence reduced to 58-70% while basalt milkvetch increased to approximately 30%. Along with enhancing stand establishment in seed production fields, these data will assist land managers in planning for optimal establishment of these species in rangeland revegetation/restoration projects. © Published by Elsevier Inc. On behalf of Society for Range Management.
    • Germination and seedling establishment of spiny hopsage in response to planting date and seedbed environment

      Shaw, N. L.; Haferkamp, M. R.; Hurd, E. G. (Society for Range Management, 1994-03-01)
      Reestablishment of spiny hopsage (Grayia spinosa [Hook.] Moq.) in the shrub steppe requires development of appropriate seeding technology. We examined the effect of planting date and seedbed environment on germination and seedling establishment of 2 seed sources at 2 southwestern Idaho sites. Seedbeds were prepared by rototilling. In 1987-88, seeds collected in 1986 were drilled at 66 viable seeds m-1 of row at Birds of Prey in late fall, winter, and early spring and at Reynolds Creek in late fall, early spring, and late spring. Seeds collected in 1986 and 1988 were broadcast at 400 viable seeds m-2 at both sites in late fall, early spring, and late spring 1988-89. Seeds in nylon bags were also planted at each site in late fall, winter, and early spring in 1987-88 and in late fall, winter, early spring, and late spring in 1988-89. On each succeeding planting date and in early summer, 5 bags of each seed source from each of the earlier planting dates were recovered. Water content, viability, and germination were compared among seeds from previous plantings and control seeds stored in the laboratory. Each year, first-year seedling establishment at both sites was favored by late fall compared to other planting dates. In 1988, seedlings established only from late fall plantings at a density of 1 m(-2) st each site. In 1989, late fall planting at the 2 sites increased seedling establishment 6 (51 vs 8 m-2) and 20 (41 vs 2 m-2) times compared to early spring planting. Germination was generally greater for seeds incubated at field sites compared to controls. Germination total and rate increased 6-11 times and 13 days from late fall 1987 to early spring 1988, 1-6 times and 4 and 9 days from winter 1988 to early spring 1988, 17 times and 10-11 days from late fall 1988 to winter 1989, and 4-7 times and 11 days from winter 1989 to early spring 1989. Late fall or early winter planting is essential to permit early spring germination when surface soils are moist.
    • Germination and Seedling Growth of Tall Wheat-Grass and Basin Wildrye in Relation to Boron

      Roundy, B. A. (Society for Range Management, 1985-05-01)
      Seedling establishment on many saline, arid rangeland soils in the Great Basin may be limited not only by low soil osmotic and matric potentials, but also by high boron concentrations. Germinationa and seedling growth of tall wheatgrass [Agropyron elongatum (Host) Beau. 'Jose'] and basin wildrye (Elymus cincereus Scribn. and Merr. 'Magnar') were measured in relation to increasing boron concentrations in laboratory and greenhouse experiments. Rate and total germination of both species were unaffected by boron concentrations up to 200 ppm, while radicle length was unaffected at less than 100 ppm. Growth of both species was much more sensitive to boron than was germination. Root growth of both species was more sensitive to boron than shoot growth. Shoot growth of Jose tall wheatgrass was less sensitive to boron than that of Magnar basin wildrye. Reduction in root and shoot yield of 50% occurred at soil saturation extract concentrations of 30 and 66 ppm of boron, respectively, for Jose tall wheatgrass, and 22 and 37 ppm of boron, respectively, for Magnar basin wildrye. Boron concentrations ranging up to 97 ppm in the saturation extract of a typical Great Basin saline soil in central Nevada would probably affect seedling growth and survival, but not emergence of these species. The fact that Jose tall wheatgrass has greater absolute root growth and boron tolerance than does Magnar basin wildrye may account, in part, for its greater seedling survival on a saline soil in central Nevada.