• A viewpoint: Rangeland health and mule deer habitat

      Clements, C. D.; Young, J. A. (Society for Range Management, 1997-03-01)
      The Lassen interstate mule deer (Odocoileus hemionus) herd ranges from the northwestern area of Nevada to the northeastern corner of California along the western rim of the Great Basin. This mule deer herd serves as a model for what has happened in terms of population dynamics for many Intermountain west mule deer populations. Before contact with Europeans the populations were apparently very restricted. After the introduction of domestic livestock there has been significant impacts on the relative abundance of shrubs versus perennial grasses. Mule deer herds underwent tremendous expansion which peaked in the 1950s. Recent mule deer population numbers in the Lassen interstate herd have sharply declined. These population dynamics can be related to several habitat changes that reflect increased frequencies of wildfires in lower elevational sites as shrubs became old and decadent. Lack of fire in the higher elevations resulted in decadent/senscent old shrub stands. Invasion by exotic annual grasses in lower elevational sites. In certain environments, sharply improved range condition due to grazing management systems. The increase in coniferous woodlands, which may reflect changes in climate and/or atmospheric gases, combined with the lack of fire significantly negatively impact the Lassen Interstate mule deer herd. Identifying the specific aspect of winter, transitional, and/or summer habitat, in terms of dietary deficiency, that are most closely related to the decline in mule deer numbers is a highly significant problem facing wildlife and range managers.
    • Bladeploughing and exclosure influence soil properties in a semi-arid Australian woodland

      Eldridge, D. J.; Robson, A. D. (Society for Range Management, 1997-03-01)
      Runoff and sediment yield were evaluated on a sandplain dominated by woody perennial shrubs in north-western NSW, Australia. The site was bladeploughed; and some plots were grazed by sheep and cattle and others exclosed from grazing. Two years after ploughing and exclosure, grazed plots had significantly lower levels of aggregate stability and organic carbon compared with ungrazed plots, but there was no effect of ploughing. Surface pH levels were significantly greater on unploughed plots compared with ploughed plots. Two years after treatment, runoff and sediment yield were greatest on plots with the least disturbance (unploughed and ungrazed) and least on sites with the greatest disturbance (ploughed and grazed). We attribute differences in soil hydrology to the development of a thin physical soil crust on the unploughed-ungrazed plots, which restricted infiltration. On the ungrazed plots, increases in plant cover and biomass, and colonisation of the physical crust by biological elements, are hypothesised to lead to reduced runoff and sediment yield over time.
    • Cheatgrass and yellow starthistle growth at 3 soil depths

      Sheley, R. L.; Larson, L. L. (Society for Range Management, 1997-03-01)
      Community dynamics and dominance on cheatgrass (Bromus tectorum L.) and yellow starthistle (Centaurea solstitialis L.) infested rangeland appear to be influenced by resource acquisition rates and duration of growth. Objectives were to determine the effects of densities, proportions, and soil depth on the growth rate and duration of growth of these species. In 6 field experiments isolated individuals, monocultures (100, 1,000, 10,000 plants m-2), and mixtures (same densities arranged factorially) were grown with unrestricted and restricted (0.2- and 0.5-m) soil depths. Shoot weights were determined on 12-day intervals beginning on day 24 and ending on day 72 for plants grown with restricted soil depth and day 96 (cheatgrass) and day 108 yellow starthistle) for plants grown in unrestricted soil. Quadratic growth curves were fit for each replication for plants grown in isolation. Linear and quadratic models season. We tested whether blue grama [Bouteloua gracilis (HBK.) Lag.] could be established in crested wheatgrass fields to increase plant diversity and grazing season length. Three seeding methods (unseeded, seed broadcast after rototilling, or seed drilled) and 2 herbicide treatments (none or glyphosate [N (phosphonomethyl)-glycine] sprayed at 1.1 kg a.iha-1) were applied in a complete factorial design to 3 X 10 m plots in 1994 in two 50 year-old crested wheatgrass stands. Blue grama established in seeded plots, but the effectiveness of seeding methods varied between sites. At both sites, herbicide control of crested wheatgrass greatly promoted the establishment of blue grama. Crested wheatgrass biomass and cover were reduced by rototilling and by spraying. The results suggest that the establishment of blue grama in crested wheatgrass stands is possible if seed is added and competition from crested wheatgrass is controlled.
    • Crested wheatgrass and shrub response to continuous or rotational grazing

      Angell, R. F. (Society for Range Management, 1997-03-01)
      A four-year study was conducted to investigate effects of continuous and short duration grazing in spring on standing crop and tiller density of crested wheatgrass [Agropyron desertorum (Fisch. ex Link) Schult], along with changes in cover and density of Wyoming big sagebrush (Artemisia tridentata Nutt. subsp. wyomingensis Beetle and Young) and green rabbitbrush [Chrysothamnus viscidiflorus (Hook.) Nutt.]. Eight pastures were each stocked with 10 steers (224 kg) beginning in early May. Four grazing treatments consisted of continuous grazing at 0.6 AUM/ha (CONT) or short duration grazing management at 0.6, 0.9, and 1.2 AUM/ha for LOW, MED, and HIGH treatments, respectively. After 4 years, mean tiller density was greatest on LOW paddocks (P = 0.10) (707 tillers/m2). Tiller density on HIGH paddocks did not differ (P > 0.05) from CONT. Density of large (> 15-cm tall) Wyoming big sagebrush increased (P less than or equal to 0.05) across years, but did not vary (P > 0.05) among treatments, at about 9 plants/100 m2. Sagebrush plants < 15-cm tall responded differently (P = 0.02) in CONT compared to HIGH. Small sagebrush density increased under short duration grazing at doubled stocking rate (HIGH) compared to CONT, but LOW and MED did not differ from CONT. We concluded that short duration rotation grazing at a conventional stocking rate decreased neither tillering nor yield of crested wheatgrass. Shrub density and cover changes on LOW were similar to CONT. It does appear, however, that short duration grazing at the doubled stocking rate has the potential to limit crested wheatgrass productivity over time because of enhanced sagebrush seedling survival.
    • Economic feasibility of rangeland seeding in the arid south-west

      Ethridge, D. E.; Sherwood, R. D.; Sosebee, R. E.; Herbel, C. H. (Society for Range Management, 1997-03-01)
      Results from 6 years of seeding trials in the Chihuahuan Desert indicated that establishment of introduced and native grass species responded directly to soil moisture at the 1.22 cm (0.5 in) depth, soil temperature at the 5.08 cm (2 in) depth, and seedbed preparations of mulching and pits. The economic analysis indicated that seeding is not an advisable financial investment in the region under general circumstances. It also showed that when seeding is deemed necessary the best native species economic alternatives are blue grama [Bouteloma gracilis (H.B.K.) Griffiths] with either no seedbed preparation or with post seedbed preparation of mulch. The best introduced species economic alternative is Lehmann lovegrass (Eragrostis lehmanniana Nees.), with no seedbed preparation.
    • Effect of seed treatment on germination and emergence of 3 warm-season grasses

      Voigt, P. W.; Tischler, C. R. (Society for Range Management, 1997-03-01)
      Seed dormancy can hinder stand establishment and delay progress of genetic and plant improvement studies. Our objective was to evaluate the effect of 2 chemical seed treatments on germination and on emergence and survival of 3 warm-season grasses. Freshly harvested seed of kleingrass (Panicum coloratum L.) weeping lovegrass [Eragrostis curvula (Schrad.) Nees] and wilman lovegrass (Eragrostis superba Peyr.) were treated with concentrated H2SO4 or a 2-chloroethanol sodium hypochlorite (CHL) solution and then germinated on blotters or planted in a commercial peat-vermiculite mix. The 3 grasses responded differently to acid and CHL treatment. Acid treatment increased germination of all 3 species but did not increase the emergence and/or 2 week establishment of weeping or wilman lovegrass. The difference between germination and emergence appeared related to chemical injury from the acid treatment that adversely impacted seedling growth and development. Weeping lovegrass responded to CHL treatment with increased germination and emergence. Wilman lovegrass did not respond well to either chemical.
    • Factors affecting private rangeland lease rates

      Vantassell, L. W.; McNeley, S. M. (Society for Range Management, 1997-03-01)
      Private rangeland lease rates have been used historically as an indication of the price of public grazing lease rates. The ability of these prices to adequately reflect short-term fluctuations in the rancher's ability to pay for forage has been questioned by policy makers and researchers. Multiple regression techniques were used in this study to evaluate how responsive private rangeland lease rates have been to short-term (yearly) fluctuations in market conditions. Independent variables included yearling prices, cattle numbers, hay prices, production cost index, land prices, forage condition index, and the previous year's lease rate. Yearling prices lagged 1 year, hay prices, production cost index lagged 1 year, and lease rates lagged 1 year statistically (P < 0.10) explained lease rates. The previous year's lease rate was the most influential explanatory variable, with more than half of the previous year's lease price reflected in the current year's rate. Statistically significant (P < 0.10) differences in lease rates were also found between western regions.
    • Field measurement of etiolated growth of rhizomatous grasses

      Reece, P. E.; Nichols, J. T.; Brummer, J. E.; Engel, R. K. (Society for Range Management, 1997-03-01)
      Defoliation effects on grasses have been quantified with measurements of etiolated growth since the 1960's, however, field techniques for measuring etiolated growth of rhizomatous grasses with dispersed tillers have not been reported. Tents constructed with landscape fabric were used in a field study of 2 species of rhizomatous grass. When manufactured, the woven polypropylene fabric is needle punched for air and water permeability. Light that may pass through perforations has no measurable effect on etiolated growth as indicated by a test of single and double layers of fabric. Tents can be sized to shade borders around interior sample areas to prevent translocation from outside tillers to harvested tillers. Landscape fabric tents are light weight and reusable and eliminate breakage, water vapor, and storage problems associated with other covers.
    • Golden memories—golden opportunities

      Hunter, J. R. (Society for Range Management, 1997-03-01)
      Address given at the Society's 50th Annual Meeting on Feb. 17, 1997 in Rapid City, IA.
    • Growth and freezing tolerance of winterfat seedlings

      Hou, J.; Romo, J. T. (Society for Range Management, 1997-03-01)
      Tolerance to freezing temperatures may be an important factor in the regeneration ecology of winterfat (Ceratoides lanata (Pursh) J.T. Howell). Therefore, growth and freezing tolerance of winterfat seedlings were determined after being grown under different controlled temperatures for 7, 14, 21, or 28 days. Growth of seedlings was greater under day temperatures of 15 and 20 degrees C relative to 5 and 10 degrees C. Freezing tolerance of seedlings was dependent on seedling age and growth conditions. Younger seedlings were more freezing tolerant than older ones grown under the same environmental conditions. Seedlings grown under lower temperatures were more freezing tolerant than those grown under higher temperatures. The lowest observed lethal temperature for 50% mortality (LT50) was -11.8 degrees C for 7-day old seedlings grown under 10/0 degrees C alternating temperatures, and the highest LT50 was about -5 degrees C for seedlings 28 days of age when grown under 29/1 degrees C. Based on seedbed temperatures in the field, the results suggest that freezing temperatures may indeed limit the establishment of winterfat seedlings on Northern Mixed Prairie. Seedbeds with litter accumulations or standing dead plant material may ameliorate low temperature extremes and reduce mortality of winterfat seedlings.
    • Hydrologic characteristics of vegetation types as affected by prescribed burning

      Hester, J. W.; Thurow, T. L.; Taylor, C. A. (Society for Range Management, 1997-03-01)
      The objective of this study was to determine how rangeland hydrology of oak, juniper, bunchgrass and shortgrass vegetation types is altered by fire. The research was conducted at the Sonora Agricultural Experiment Station on the Edwards Plateau, Texas. Infiltration rate and interrill erosion were measured using a drip-type rainfall simulator. Terminal infiltration rates of unburned areas were significantly greater on sites dominated by oak (Quercus virginiana Mill.) (200 mm hour-1) or juniper (Juniperus ashei Buchh.) (183 mm hour-1) than on sites dominated by bunch-grass (146 mm hour-1) or shortgrass (105 mm hour-1). Terminal infiltration rates on burned areas were significantly reduced on sites dominated by bunchgrass (110 mm hour-1), shortgrass (76 mm hour-1), and on oak sites that were cut and burned (129 mm hour-1). Soil organic matter content (r = .61), total organic cover (r = .59), and aggregate stability (r = .53) were the variables most strongly correlated with infiltration rate. Measured soil structure properties were not altered by fire, therefore, differences in infiltration rate between unburned and burned treatments were attributable to variations in the amount of cover. The terminal infiltration rate of cut and burned juniper sites (162 mm hour-1) was not changed significantly after the fire because the associated good soil structure properties allowed rapid infiltration even after cover was removed. Good soil structure properties were also present on the oak sites, but the infiltration rate significantly decreased as a result of the temporary hydrophobic nature of the soil on this site after burning. Prior to burning, interrill erosion was much lower under the tree sites (oak = 2 kg ha-1; juniper = 34 kg ha-1) than on bunchgrass (300 kg ha-1) or shortgrass (1,299 kg ha-1) sites. After burning, interrill erosion significantly increased for all vegetation types (shortgrass = 5,766 kg ha-1; bunchgrass = 4,463 kg ha-1; oak = 4,500 kg ha-1; juniper = 1,926 kg ha-1). Total organic cover (r = -.74) and bulk density at 0-30 mm (r = .46) were most strongly correlated with interrill erosion.
    • Leaf nutritive value related to tiller development in warm-season grasses

      Hendrickson, J. R.; Moser, L. E.; Moore, K. J.; Waller, S. S. (Society for Range Management, 1997-03-01)
      Assessing nutritive value of key grass species in relation to plant development is essential for producers to efficiently manage livestock enterprises. Changes in nutritive value for tiller populations of 2 common Nebraska Sandhills grasses, prairie sandreed [Calamovilfa longifolia (Hook.) Scribn.] and sand bluestem [Andropogon gerardii var. paucipilus (Nash) Fern], in response to morphological development was evaluated at the Gudmundsen Sandhills Laboratory (GSL) during the 1990 and 1991 growing seasons. Morphological development was determined on a 40 to 60-tiller sample from each block (12 blocks in 1990 and 8 blocks in 1991) at ten-day intervals using a comprehensive staging system. In vitro dry matter digestibility (IVDMD), crude protein (CP), neutral detergent fiber (NDF) and lignin were determined for leaves and correlated with the morphological index (Mean Stage by Count), growing degree days and day of the year. Leaf NDF values of both species remained constant while leaf IVDMD declined throughout the summer indicating that decline in leaf IVDMD was caused by declining cell wall digestibility. Leaf IVDMD was influenced more by tissue aging than advancing morphological stage. Leaf CP was significantly different between years but not between species indicating leaf CP was largely influenced by environmental factors. In both species and for both years, leaf CP initially declined rapidly to low levels and then stabilized during the vegetative phase. Nutritive value of a single vegetative morphological stage over the growing season was similar to the leaf tissue of the tiller populations. Management decisions by producers depend on accurate assessment of changes in nutritive value during the growing season in tiller populations of these 2 important grasses.
    • Leafy spurge control with angora goats and herbicides

      Lym, R. G.; Sedivec, K. K.; Kirby, D. R. (Society for Range Management, 1997-03-01)
      A 4-year experiment to evaluate herbicide treatments with grazing by goats to improve long-term leafy spurge (Euphorbia esula L.) control compared to either herbicides or goats was established on the Sheyenne National Grasslands and the Gilbert C. Grafton South State Military Reservation in North Dakota. Six treatments were evaluated including an untreated control, grazing alone, herbicides applied in the spring or fall alone, grazing following spring-applied herbicides, or grazing during the season prior to fall-applied herbicides. Leafy spurge was rotationally grazed at the Sheyenne National Grasslands but was grazed season-long at Camp Grafton South. Grazing combined with fall-applied herbicide treatment reduced leafy spurge density rapidly and maintained control longer than either method used alone. Picloram (4-amino-3,5,6-trichloro- pyridinecarboxylic acid) plus 2,4-D [(2,4-dichlorophenoxy)acetic acid] applied annually in the spring reduced leafy spurge density similar to or better than the same treatment combined with grazing. Also, leafy spurge control tended to be more rapid with continuous than rotational grazing. The best treatments averaged over both locations were picloram plus 2,4-D at 0.5 plus 1.1 kg ha-1 applied in the fall alone or preceded by spring grazing. These treatments reduced the stem density by 98% from an average of 16 stems per 0.25 m2 at the start of the experiment to 0.3 stem per 0.25 m2 3 years later. Leafy spurge stem density still only averaged 1 stem per 0.25 m2 12 months after the last treatment of season-long grazing plus a fall herbicide treatment compared to 6.5 stems per 0.25 m2 when either method was used alone. Grazing and herbicide treatments alone or in combination reduced the root protein content at both locations but the effect on root carbohydrate content was minimal.
    • Pasture development during brush clearing with sheep and goats

      Dabaan, M. E.; Magadlea, A. M.; Bryan, W. B.; Arbogast, B. L.; Prigge, E. C.; Flores, G.; Skousen, J. G. (Society for Range Management, 1997-03-01)
      Knowing that sheep or goats can be used to control brush we quantified pasture changes during and after brush control. Over an 8-year period we measured the effects of control (no soil amendment), medium soil amendment (4,500 kg lime and 40 kg P ha-1), and high soil amendment (9,000 kg lime and 117 kg P ha-1) on soil fertility, pasture botanical composition and production of brushy pasture grazed by sheep or goats. Botanical composition was estimated from clipped samples. Soil pH was 4.8 in the control, 6.5 in the medium and 7.0 in the high amendment plots. Medium and high amendment increased legume dry matter in the pasture from 2 in the check to 8%. More animal grazing days were obtained on paddocks treated with lime and P. Grazing with sheep or goats and lime and application of P resulted, after 4 years, in pastures with a grass, legume, and other broadleaf plant composition similar to that of brush-free, natural pasture.
    • Plant, small mammal, and avian diversity following control of honey mesquite

      Nolte, K. R.; Fulbright, T. E. (Society for Range Management, 1997-03-01)
      The effects of herbicide applications to kill honey mesquite (Prosopis glandulosa Torr.) on community diversity are poorly documented. Our objective was to test the hypothesis that herbicide application to kill honey mesquite would reduce plant and vertebrate species richness and diversity. A 1:1 mixture of triclopyr ([(3,5,6-trichloro-2-pyridinyl) oxy]acetic acid) + picloram (4-amino-3,5,6-tricholopicolinic acid) was applied to three 13-ha plots during 1992 and to 3 additional plots in 1993. Mesquite and forb canopy cover in the zone less than or equal to 1 m from the soil surface were lower within treated plots than in control plots (n = 3) following the 1992 and 1993 treatments. Grass canopy cover did not differ between herbicide-treated plots and control plots. Vegetation species richness and evenness, Shannon's index, beta diversity, and proportion of rare plant species did not differ between controls and sites treated during 1992 and 1993. Rodent and avian relative frequency, richness, and diversity were not different on 1992 herbicide treatment plots and controls. Based on these results, application of triclopyr + picloram in mesquite-mixed grass communities in the Texas Coastal Bend does not appear to reduce plant and vertebrate species richness and diversity within the first 2 years after treatment. However, our results should be interpreted cautiously because (1) annual rainfall was 16% above the annual average during the study and (2) limited replication possibly reduced statistical power to detect differences.
    • Seed production, seed rain, and the seedbank of fringed sagebrush

      Bai, Y.; Romo, J. T. (Society for Range Management, 1997-03-01)
      Increases in fringed sagebrush (Artemisia frigida Willd.) following disturbance on Northern Mixed Prairie are due to enhanced growth of established plants and seedling recruitment. The roles of seed production and the soil seedbank in population dynamics of fringed sagebrush following disturbance are, however, unknown. Furthermore, seed rain has not been documented for this species. The objectives of this study were to determine: 1) the effect of disturbances in the sward on seed production; 2) relationships between the soil seedbank and current seed production; and 3) seed rain over time for fringed sagebrush. Disturbances of clipping, litter removal, tillage, and a combination of clipping and litter removal were imposed on a sandy range site in central Saskatchewan. Following disturbance seed production plant-1 either increased or was unchanged compared to the undisturbed control. Greater seed production resulted from increased production of seeds head-1, heads inflorescence-1 and inflorescences plant-1. The timing of seed rain varied considerably among individual plants. Five temporal patterns of seed rain were identified for individual fringed sagebrush plants: 1) 5.2% of the plants began and completed dispersing seeds within 6 to 8 weeks of flowering; 2) 20.8% began dispersing within 6 to 8 weeks of flowering and completed dispersal before snow was received in autumn; 3) 37.7% began dispersing seeds within 6 to 8 weeks of flowering and continued over the winter; 4) 29.9% delayed dispersal of seeds more than 8 weeks after flowering and continued over the winter; and 5) 6.5% began and completed seed dispersal during the winter. The number of fringed sagebrush seeds in the soil was correlated with seed production only when many seeds were produced (r=0.76), indicating that annual seed production is of limited importance for maintaining a seedbank. A persistent seedbank is important in maintaining fringed sagebrush populations when seed production is limited. Diverse rates and times of seed rain along with a persistent seedbank may enable fringed sagebrush to occupy safe sites that develop in time.
    • Seeding blue grama in old crested wheatgrass fields in southwestern Saskatchewan

      Bakker, J. D.; Christian, J.; Wilson, S. D.; Waddington, J. (Society for Range Management, 1997-03-01)
      Crested wheatgrass [Agropyron cristatum (L.) Gaertn.] fields have low plant diversity and a limited grazing season. We tested whether blue grama [Bouteloua gracilis (HBK.) Lag.] could be established in crested wheatgrass fields to increase plant diversity and grazing season length. Three seeding methods (unseeded, seed broadcast after rototilling, or seed drilled) and 2 herbicide treatments (none or glyphosate [N (phosphonomethyl)-glycine] sprayed at 1.1 kg a.iha-1) were applied in a complete factorial design to 3 X 10 m plots in 1994 in two 50 year-old crested wheatgrass stands. Blue grama established in seeded plots, but the effectiveness of seeding methods varied between sites. At both sites, herbicide control of crested wheatgrass greatly promoted the establishment of blue grama. Crested wheatgrass biomass and cover were reduced by rototilling and by spraying. The results suggest that the establishment of blue grama in crested wheatgrass stands is possible if seed is added and competition from crested wheatgrass is controlled.
    • Shrub species richness beneath honey mesquite on root-plowed rangeland

      Stewart, K. M.; Bonner, J. P.; Palmer, G. R.; Patten, S. F.; Fulbright, T. E. (Society for Range Management, 1997-03-01)
      Root-plowed rangeland in southern Texas is often dominated by fabaceous shrubs. We tested the hypothesis that the shrub community present 40 years after rootplowing does not exhibit successional trends toward the mixed-brush species community that existed before rootplowing. Twenty shrub clusters, each organized around a central honey mesquite individual, were selected within a control site and a root-plowed (35-40 years ago) site at each of 3 locations. Number of all woody plants species including cacti Opuntia spp. and Yucca spp. beneath the nuclear honey mesquite was determined. Shrub species richness within clusters increased with increasing central honey mesquite basal diameter on control and root-plowed sites. Species richness/honey mesquite in root-plowed (2 +/- 0.5 species, +/- SE) sites was lower than species richness/honey mesquite > 200 mm in diameter on control sites (7 +/- 0.4 species/honey mesquite). Honey mesquite seedlings (1-60 mm basal stem diameter) composed 39 +/- 14% of the shrubs beneath honey mesquite canopies on root-plowed sites compared to less than or equal to 3% of the woody plants present on untreated sites. Honey mesquite may continue to dominate root-plowed sites for some time, since honey mesquite was the major subordinate shrub species on root-plowed sites.
    • Viewpoint: Ungulate herbivory, willows, and political ecology in Yellowstone

      Kay, C. E. (Society for Range Management, 1997-03-01)
      Contentions that willows (Salix spp.) on Yellowstone National Park's northern range have declined because of climatic change, fire suppression, reduced chemical defenses, or other natural factors are not supported by available data. Instead, willows have declined due to repeated browsing by an unnaturally large elk population. By established standards Yellowstone contains some of the worst overgrazed willow communities in the entire West, but that was not true in earlier times. Prior to park establishment, predation by Native Americans kept elk and other ungulate numbers low which, in turn, prevented herbivores from impacting Yellowstone's plant communities, as those animals do today. Finally, the condition of willows in the park is also a test of Yellowstone's "natural regulation" program, and that paradigm must also be rejected.