• A Riparian Research Program

      Prouty, Mike (Society for Range Management, 1987-12-01)
    • An Evaluation of Dimension Analysis for Predicting Shrub Biomass

      Murray, R. B.; Jacobson, M. Q. (Society for Range Management, 1982-07-01)
      Fifteen independent variables consisting of circumference, surface area, and volume for various assumed shapes were derived from simple diameter and height measurements. These variables were used in seven models to predict aboveground biomass of leaves, different sizes of live and dead twigs, and combinations of fractions for threetip sagebrush, gray horsebrush, green rabbitbrush, and broom snakeweed. In addition, models based on height and circumference were tested on each species and fraction. A simple linear model with surface area or volume as independent variables and height × circumference models gave the best biomass predictions for these species.
    • An investigation on fire effects within xeric sage grouse brood habitat

      Fischer, R. A.; Reese, K. P.; Connelly, J. W. (Society for Range Management, 1996-05-01)
      We investigated the short-term influence of fire on xeric sage grouse (Centrocercus urophasianus) brood habitat in southeastern Idaho from 1990-92. A prescribed fire in 1989 removed Wyoming big sagebrush (Artemisia tridentata wyomingensis Nutt.)/threetip sagebrush (A. tripartita Rydb.) canopy cover from approximately 57% of a 5,800-ha area, potentially influencing brood-rearing habitat. Although the fire created a mosaic of sagebrush areas interspersed with open areas having abundant grasses and forbs, the relative abundance of males, females, and broods on survey routes in burned and unburned habitat were similar. Cover of forbs important in sage grouse summer diets was similar in burned and unburned habitat. However, the abundance of Hymenoptera, an insect Order important in sage grouse diets, was significantly lower in burned habitat the second and third years postburn. Our research did not support the contention that fire may enhance sage grouse brood-rearing habitat.
    • Assessing the Success of Postfire Reseeding in Semiarid Rangelands Using Terra MODIS

      Chen, Fang; Weber, Keith T.; Schnase, John L. (Society for Range Management, 2012-09-01)
      Successful postfire reseeding efforts can aid rangeland ecosystem recovery by rapidly establishing a desired plant community and thereby reducing the likelihood of infestation by invasive plants. Although the success of postfire remediation is critical, few efforts have been made to leverage existing geospatial technologies to develop methodologies to assess reseeding success following a fire. In this study, Terra Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data were used to improve the capacity to assess postfire reseeding rehabilitation efforts, with particular emphasis on the semiarid rangelands of Idaho. Analysis of MODIS data demonstrated a positive effect of reseeding on rangeland ecosystem recovery, as well as differences in vegetation between reseeded areas and burned areas where no reseeding had occurred (P<0.05). We conclude that MODIS provides useful data to assess the success of postfire reseeding./Esfuerzos exitosos de resiembra post-fuego pueden ayudar a los ecosistemas de pastizales para regenerarse rápidamente, estableciendo una comunidad deseable de plantas y reduciendo la probabilidad de infestación de plantas invasivas. Mientras el éxito del mejoramiento post-fuego es crucial, pocos esfuerzos se han hecho para aprovechar las tecnologías geospeciales existentes para desarrollar metodologías encaminadas a medir el éxito en la resiembra después de la presencia de fuego. En este estudio, información de satélite Terra Moderate Resolution Imaging Spectroradiometer (MODIS) se usó para mejorar la capacidad de determinar los trabajos de rehabilitación post-fuego, con un particular énfasis en los pastizales semiáridos de Idaho. Análisis de información de MODIS demostraron un efecto positivo de resiembra en la recuperación de los ecosistemas depastizales así como en diferencias en vegetación entre áreas resembradas y áreas quemadas donde la resiembra no ha ocurrido (P<0.05). Se concluyó que MODIS provee información útil para determinar el é́xito de las resiembras post-fuego.
    • Association of the wheat stem sawfly with basin wildrye

      Youtie, B. A.; Johnson, J. B. (Society for Range Management, 1988-07-01)
      The association of the wheat stem sawfly (Cephus cinctus Nort., Hymenoptera: Cephidae) and basin wildrye (Elymus cinereus Scribn. & Merr) was investigated in 2 wildrye stands in southern Idaho during the summers of 1982 and 1983. From 62 to 88% of wildrye plants were infested with the sawfly at the Idaho National Engineering Laboratory and Craters of the Moon National Monument. Plant phenology was a good predictor of sawfly emergence. Larvae that developed within culms consumed vascular tissues and may have impaired transport of water and carbohydrates. Seed weight and the number of caryopses developing within wildrye florets were significantly reduced in culms containing sawfly larvae (P<0.006 and P<0.018, respectively). Germination rates of seeds from infested and non-infested culms were not significantly different (P>0.05).
    • Bitterbrush and cheatgrass quality on 3 southwest Idaho winter ranges

      Bishop, C. J.; Garton, E. O.; Unsworth, J. W. (Society for Range Management, 2001-09-01)
      Nutritional stress is an important mortality factor for wintering mule deer (Odocoileus hemionus hemionus Rafinesque), particularly fawns. The rate at which fawns utilize existing fat stores is at least partially dependent upon the quality of available forage during winter. Although numerous studies have determined the nutritive value of various forage species, more research is needed to determine whether individual forage species vary in quality across the landscape. We determined whether differences existed in the nutritional quality of antelope bitterbrush (Purshia tridentata [Pursh] DC.) and cheatgrass brome (Bromus tectorum L.) among 3 winter ranges and 6 habitats within the winter ranges. In vitro dry matter digestibility (IVDMD) of bitterbrush varied among winter ranges in 1996 and 1997 (P < 0.001). The highest mean IVDMD measured on a winter range was 29.8% (n = 36, SD = 3.87) in 1997 while the lowest was 15.2% (n = 38, SD = 4.42) in 1996. Bitterbrush crude protein (CP) was different among habitats in 1997 (P = 0.005), with mean CP values ranging from 7.0% (n = 19, SD = 0.73) to 8.0% (n = 13, SD = 0.70). The length and diameter of available bitterbrush leaders varied within and among winter ranges because of differential utilization. Bitterbrush IVDMD and CP varied in relation to the mean diameter of leaders obtained from each random sampling site (P 0.001). The quality of bitterbrush decreased as browse intensity increased. Cheatgrass IVDMD was different between winter ranges (P < 0.001) in 1996, with mean values ranging from 65.8% (n = 36, SD = 4.34) to 69.6% (n = 36, SD = 3.83). Site-specific variation should be considered when evaluating the nutritional quality of mule deer habitat, at least during winter when species diversity in deer diets is limited.
    • Black-tailed Jackrabbit Diet and Density on Rangeland and Near Agricultural Crops

      Fagerstone, K. A.; LaVoie, G. K.; Griffith, R. E. (Society for Range Management, 1980-05-01)
      Black-tailed jackrabbit diets and densities were compared between rangeland and cultivated areas in southern Idaho to determine how heavily jackrabbits rely on crops for spring and summer food. Jackrabbit densities were significantly higher near cultivated crops than on the isolated rangeland. Where barley and crested wheatgrass plants were available to jackrabbits, they were preferred foods and made up a large part of the spring and summer diet. As potato plants were not a highly preferred food, crop, damage by jackrabbits could probably be reduced by planting potatoes in a buffer strip between rangeland and preferred grain crops. Plant phenology was a major factor in determining food preferences of jackrabbits collected on rangeland. In the spring, 85% of rangeland diet consisted of grass. However, in early summer, grasses and forbs were eaten in equal amounts and by late summer, 71% of the diet was comprised of forbs and shrubs.
    • Bowen ratio versus canopy chamber CO2 fluxes on sagebrush rangeland

      Johnson, D. A.; Saliendra, N. Z.; Walker, J. W.; Hendrickson, J. R. (Society for Range Management, 2003-09-01)
      Because of their expansiveness, sagebrush (Artemisia spp.)-steppe rangelands could contribute significantly to the global carbon budget. However, it is important to determine if there are differences between methods for determining CO2 fluxes on these rangelands. The objective of this study was to compare the Bowen ratio-energy balance and canopy chamber techniques for measuring CO2 fluxes in a sagebrush-steppe ecosystem. A Bowen ratio-energy balance system was installed at a sagebrush-steppe site near Dubois, Ida., U.S.A to continuously measure the vertical gradients of air temperature, water vapor, and CO2 concentration in conjunction with associated micrometeorological characteristics. The canopy chamber technique, which employed a 1-m2 (1,020 liter) clear plexiglass/plastic film chamber in combination with a portable gas exchange system, was used periodically during May through August across 4 years (1996-1999) to obtain instantaneous measurements of CO2 fluxes across 3 replicate blocks during a 2-min. measurement period. For the same measurement dates and times across the 4 years of study, CO2 fluxes ranged from -0.22 to 0.55 mg m-2 sec-1 for the Bowen ratio-energy balance technique and from -0.18 to 0.48 mg m-2 sec-1 for the canopy chamber technique. Estimates of CO2 fluxes by the 2 techniques were not statistically different (P > 0.05) for the early (May) and mid-season (June to mid-July) portions of the growing season; however, fluxes measured by the 2 techniques were significantly different (P 0.05) for the late-season period (late-July to late-August). Despite this difference during the hot-dry, late-season period, flux estimates from the 2 techniques were significantly and positively correlated during the early (r2 = 0.71), mid- (r2 = 0.88), and late- (r2 = 0.72) season periods. Thus, both techniques showed similar patterns of CO2 fluxes at our sagebrush-steppe study site across 4 years of study, although caution should be used when the canopy chamber technique is used during hot, dry conditions.
    • Cattle and Fish on the Henry's Fork

      Platts, William S.; Wagstaff, Fred J.; Chaney, Ed (Society for Range Management, 1989-06-01)
    • Cattle Distribution Under Intensive Herded Management

      Butler, Paul J. (Society for Range Management, 2000-04-01)
    • Characterization of diversity among 3 squirreltail taxa

      Jones, T. A.; Nielson, D. C.; Arredondo, J. T.; Redinbaugh, M. G. (Society for Range Management, 2003-09-01)
      Squirreltail (Elymus elymoides, E. multisetus) is a complex of 5 taxa whose systematic interrelationships are uncertain. Our objectives were to determine whether the 3 taxa studied here, Elymus elymoides ssp. elymoides, E. elymoides ssp. brevifolius, and E. multisetus, can be distinguished by several ecological and physiological traits and whether geographical origin is correlated with these traits across accessions within taxa. A multivariate principal component analysis of materials collected in the 10 contiguous western states successfully distinguished taxa, but no pair of the 3 taxa appeared to be more ecologically similar than any other pair. Elymus elymoides ssp. elymoides, which prevails in the semi-arid cold desert, was shortest and exhibited the lowest total plant dry-matter, earliest phenology, and lowest seed mass. Elymus elymoides ssp. brevifolius, which prevails in the Rocky Mountains, exhibited slowest emergence, highest specific root length, lowest nitrate reductase activity, and lowest root-to-shoot ratio. Elymus multisetus, which is most common in areas with relatively warm springs, exhibited fastest emergence (particularly from deep seeding), greatest root length, and greatest root-to-shoot ratio. Elymus elymoides ssp. brevifolius accessions clustered into 3 groups: late-maturing high-seed mass accessions originating in Colorado, New Mexico, and Arizona (Group A), early-maturing low-seed mass accessions originating in Colorado and Utah (Group B), and intermediate-maturing low-seed mass accessions originating in the Snake River Plain of southern Idaho (Group C). The ecologically distinct subspecies and groups within ssp. brevifolius are indicative of the highly ecotypic nature of the squirreltails, suggesting that restoration practitioners should match site with genetically and ecologically appropriate plant material for these species.
    • Chemical Control of Crupina vulgaris, a New Range Weed in Idaho and the United States

      Belles, W. S.; Wattenbarger, D. W.; Lee, G. A. (Society for Range Management, 1981-11-01)
      Crupina vulgaris, crupina, a member of the Compositae family, is a recently introduced threat to the rangelands of Idaho. It is a competitive winter annual which, when established, develops nearly solid stands to the exclusion of desirable forage species. It was demonstrated by field trials that fall and spring application of picloram, glyphosate, dicamba, and 2,4-D (amine) were effective in greatly reducing or eliminating crupina for 2 years. Once crupina was removed by this effective management tool, desirable forage species replaced the unpalatable crupina.
    • Circumstances Associated with Predation Rates on Sheep and Goats

      Nass, R. D.; Lynch, G.; Theade, J. (Society for Range Management, 1984-09-01)
      Factors possibly associated with high (over 5%) and low (0-5%) predation intensities were compared among 95 sheep or goat producers in 5 states to determine if important differences were evident between the 2 groups. Data were compared for the following variables: losses to predation, flock size, type of ranch operation, management practices, predator indices, prey indices, use of U.S. Animal Damage Control program, private control efforts, predation history, timing of predation, and presence of other sheep or goats nearby. Overall, 45% of the producers reported over 5% predation losses of their lambs or kids and predation percentages tended to increase with decreased flock sizes. Feeder lamb and range sheep operations had predominantly low predation loss percentages, but most operations that included goats reported over 5% predation losses due to goat predation. A variety of management practices were used by both groups; however, low loss producers indicated low natural prey and predator populations. Most of the producers used the federal ADC program and some type of private control effort, although more high loss producers used both types. Rough, bottom, and brush grazing lands, historic predation problems, and high predator indices characterized many of the high loss producers.
    • Columbia Ground Squirrel in Subalpine Forest Openings in Central Idaho

      Lambeth, R.; Hironaka, M. (Society for Range Management, 1982-07-01)
      Columbia ground squirrels were studied in natural alpine forest openings. Three sites were selected having the same potential but presently with different vegetation due to differing levels of past domestic sheep use. Ground squirrel population was least in the light-use area and increased with vegetation change induced by increased sheep use. Juveniles were most plentiful in the medium-use site and least in the heavy-use area. Up to a point, ground squirrel population increased with plant retrogression. With continued retrogression the community became less suitable to support a healthy population because of less preferred forage species. Lupinus sericeus was the most preferred forb. Other species included Achillea millefolium and Descurania richardsonii, species not generally preferred by sheep. The discussion of sheep-ground squirrel relative impacts also considers metabolic requirement, grazing period and animal density of both grazers.
    • Comparing the economic value of forage on public lands for wildlife and livestock

      Loomis, J.; Donnelly, D.; Sorg-Swanson, C. (Society for Range Management, 1989-03-01)
      Deciding how to allocate forage among animals is a fundamentally important process in range management. The wisdom of these decisions can be enhanced by estimating the marginal value of forage needed by competing species. We present a method for obtaining such estimates and apply this method to generate net economic values of forage for elk and deer in Challis, Idaho. Specifically, a demand curve derived using a regional travel cost model is used to statistically estimate the marginal value of wildlife and forage. Comparisons of the value of forage to livestock and wildlife indicate equivalent values in the Challis, Idaho, area for these 2 uses.
    • Comparison of forage value on private and public grazing leases

      Van Tassell, L. W.; Torrell, L. A.; Rimbey, N. R.; Bartlett, E. T. (Society for Range Management, 1997-05-01)
      Federal land grazing fees have been set by a formula that uses a base rate developed from a 1966 study comparing total grazing costs on private and public lands. A similar market comparison was recently conducted in Idaho, New Mexico, and Wyoming. Total grazing costs were adhered through personal interviews from 258 ranchers using 245 public grazing permits and 149 private leases. Public land grazing permit values were also estimated in each state. This study demonstrated that many public land ranchers have been willing to pay more for grazing than the apparent value implied from the private forage market. With the 1992 grazing fee of 1.92/animal unit month (AUM), 34% of Bureau of Land Management (BLM) cattle producers, 62% of U.S. Forest Service (USFS) cattle producers, 60% of BLM sheep producers and 92% of USFS sheep producers paid more for grazing public lands than did those grazing privately leased lands. Estimated forage values averaged 3.63/AUM for cattle grazing BLM land, and were negative for cattle using USFS lands and for sheep using both BLM and USFS allotments. Using a 3.35% interest rate to amortize permit value, the annual value of public land forage was estimated to be from 3 to 5/AUM. Doubts were cast about the standard assumptions that ranchers have profit maximization as their primary goal, that permit value measures only excess forage value, and that sufficient private leases are available for a valid comparison between private and public forage markets.
    • Comparison of sheep and goat preferences for leafy spurge

      Walker, J. W.; Kronberg, S. L.; Al-Rowaily, S. L.; West, N. E. (Society for Range Management, 1994-11-01)
      The objective of these studies was to compare preference for leafy spurge (Euphorbia esula L.) by sheep and goats. Study 1 was a choice test that paired leafy spurge with either arrowleaf balsamroot (Balsamorhiza sagittata (Pursh) Nutt.) or crested wheatgrass (Agropyron cristatum (L.)Gaertn.) for a 30 minute feeding period. Study 2 consisted of 3 grazing trials on spurge-infested pastures. Differences between sheep and goat grazing were measured using capacitance meter estimates of standing crop and ocular estimates of composition; counts of grazed and ungrazed leafy spurge stems; and bite counts to estimate botanical composition of diets. The paired choice study showed that selection for leafy spurge was affected by the interaction (P < 0.0001) of animal species and the choice alternative. Goats preferred leafy spurge (80% of consumption) compared to arrowleaf balsamroot, but demonstrated a relative avoidance (33% of consumption) of leafy spurge when paired with crested wheatgrass. Sheep always avoided leafy spurge compared to the alternative forage and consumed an average of only 28% of their intake from leafy spurge during the 30 minute test. In the grazing trials goats took 64% of their bites from leafy spurge compared to 20% for sheep. This represented a relative preference for spurge by goats compared to a strong relative avoidance by sheep. Sheep avoided areas in the pasture that had high densities of flowering spurge stems while goats were relatively unresponsive to stem densities. Goat grazing reduced the number of flowering stems. Stem numbers were 90 vs. 23 flowering stems m2 (P = .04) in sheep- and goat-grazed pastures, respectively. Goats appear to have a greater potential for biological control of leafy spurge than sheep. This advantage may be particularly important in areas where leafy spurge is relatively unpalatable, which the present study site represented.
    • Cover components on long-term seasonal sheep grazing treatments in three-tip sagebrush steppe

      Bork, E. W.; West, N. E.; Walker, J. W. (Society for Range Management, 1998-05-01)
      The effects of fall and spring sheep use on cover components and recovery following a change in seasonality of grazing practices, were studied within long-term grazing treatments of three-tip sagebrush (Artemisia tripartita Rydb.) steppe on the U.S. Sheep Experiment Station near Dubois, Ida. Few significant differences existed among treatments within the litter, moss, lichen, and soil components, but several differences in vegetational cover categories occurred. More live shrub and annual grass cover were observed in the long-term (since 1924) and new spring (since 1950) treatments than in the long-term fall (since 1924), new fall (since 1950), old exclosure (since 1940), and new exclosure (since 1950) (P < 0.01). More perennial grass and forb cover, and less dead shrub cover existed in fall-grazed treatments (P < 0.01). The new fall- grazed treatment previously grazed in the spring failed to reach a more uniform mixture of perennial growth forms after 46 years such as was evident in the long-term fall, which suggests low resilience following spring grazing. The exclosure which was heavily spring and fall-grazed prior to 1950 had even less perennial forb cover than the new fall treatment, indicating that the cessation of sheep grazing did not promote herb recovery any better than continued fall use. The direct impact of sheep herbivory and its indirect effects on the competitive relationships among major plants appear to have affected the cover of sagebrush steppe components at this study site.
    • Coyote responses to changing jackrabbit abundance affect sheep predation

      Stoddart, L. C.; Griffiths, R. E.; Knowlton, F. F. (Society for Range Management, 2001-01-01)
      Domestic sheep ranchers generally perceive abundances of natural prey and coyotes (Canis latrans) as important factors affecting coyote predation rates on sheep. To determine the effect of a changing natural prey base on coyote predation rates, we estimated coyote density and predation rates on ewes and lambs during part of 1 cycle of black-tailed jackrabbit (Lepus californicus) abundance on a 2,300 km2 area of the Idaho National Engineering Laboratory in southcentral Idaho from 1979-1985. We used 100, 1.6-km scat collection lines and 80, 1.6-km flushing transects to assess coyote and jackrabbit densities, respectively. Ewe and lamb loss rates were determined from questionnaires sent to all 13 producers grazing sheep on the area. Spring coyote density varied from 0.10 to 1.39 coyotes km-2 in response to a systematic fluctuation in jackrabbit density from 0 to 243 jackrabbits km-2. Reported total loss rates of ewes and lambs varied from 2.2 to 42.1 ewes/10(5) ewe-days and 33.0 to 163 lambs/10(5) lamb-days and were linearly and directly related to coyote density (P < 0.005). Ewe and lamb loss rates were independent of jackrabbit density (P > 0.18) except for 1 year when jackrabbits were virtually absent from the study area and the loss of lambs escalated dramatically. Our data suggest the increased losses of lambs resulted from reduced buffering by natural prey.
    • Crop coefficients for rangeland

      Wight, J. R.; Hanson, C. L. (Society for Range Management, 1990-11-01)
      Crop coefficients (Kc) provide a means of relating evapotranspiration (ET) to standard references such as pan evaporation or other climatic based reference ET’s (ET = Kc*reference ET). They have been used extensively in irrigated agriculture but only limitedly on rangelands. This study used lysimeter-measured ET to determine Kc’s for conditions where water was nonlimiting for both transpiration (T) and soil water evaporation (E) and transpiration coefficients (Tc) for conditions where E was minimal and water was nonlimiting for T. Growing season ET was measured daily with hydraulic lysimeters from mixed grass, shortgrass, and sagebrush-grass plant communities near Newell, South Dakota; Gillette, Wyoming; and Reynolds, Idaho, respectively. From seasonal plots of daily ET/reference ET, lysimeter-measured ET, and daily precipitation, time periods were identified, following periods of precipitation, that met the conditions for determining Kc and Tc values. The Kc values were relatively constant among the 3 study sites and over most of the growing season ranging from 0.75 to 0.90. Maximum Tc varied among years with most of the values occurring within the 0.40 to 0.60 range.