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  Journal of Range Management, Volume 40, Number 6 (November 1987)

  Society for Range Management, 1987-11-01
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  Journal of Range Management, Volume 40, Number 4 (July 1987)

  Society for Range Management, 1987-07-01
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  Journal of Range Management, Volume 40, Number 5 (September 1987)

  Society for Range Management, 1987-09-01
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  Journal of Range Management, Volume 40, Number 3 (May 1987)

  Society for Range Management, 1987-05-01
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  Journal of Range Management, Volume 40, Number 2 (March 1987)

  Society for Range Management, 1987-03-01
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  Journal of Range Management, Volume 40, Number 1 (January 1987)

  Society for Range Management, 1987-01-01
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  Yield and Digestibility of Old World Bluestem Grasses as Affected by Cultivar, Plant Part, and Maturity

  Dabo, S. M.; Taliaferro, C. M.; Coleman, S. W.; Horn, F. P.; Claypool, P. L. (Society for Range Management, 1987-01-01)

  Old World bluestems (Bothriochloa spp.) have been used in the U.S. for over 60 years but few data are available on effects of management or cultivar differences for forage yield and quality. Field experiments were conducted on a Kirkland silt loam (Uderic Paleustoll) soil for 2 years (1982-83), in order to assess the yield and quality of 4 such cultivars as affected by maturation and plant part. The experimental design was a split-split plot, in a randomized complete block, with 4 replications, 4 cultivars ('Caucasian', 'Ganada', 'Plains', 'WW Spar'), 10 harvest dates, and 3 plant parts (whole plant, stem, and leaf). Cultivars were main plots; harvest dates and plant parts were sub and sub-sub plots, respectively. Response variables were dry matter yield (DMY), in vitro dry matter disappearance (IVDMD), leaf to stem ratio (L/S), and in vitro digestible dry matter yield (IVDDMY). Ganada consistently had the lowest leaf, stem, and whole plant DMY and IVDDMY. Caucasian had higher leaf, stem, and whole plant DMY and IVDDMY than Plains and WW-Spar in 1983, but the DMY and IVDDMY of these cultivars were similar in 1982. Quadratic and linear equations were satisfactorily fit to the DMY and IVDDMY data in 1982 and 1983, respectively. The IVDMD in whole plant samples decreased at average rates of 4.2 and $5.5 g kg ha-1 daily in 1982 and 1983, respectively, during harvest week one. Among cultivars, Caucasian had the highest rate of decline and Ganada the lowest. The decline was quadratic in nature and faster in stem fractions. Cultivar IVDMD differences were consistent over plant parts. Ganada and Caucasian had the highest and lowest IVDMD concentrations, respectively. Plains and WW-Spar had IVDMD values of similar magnitude and intermediate to those of Ganada and Caucasian. Cultivar leaf to stem ratios were similar in 1982 but different in 1983 with Plains and Caucasian having higher L/S ratios than Ganada and WW-Spar. For these cultivars leafiness was a poor indicator of digestibility.
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  Wet-Dry Cycle Effects on Warm-Season Grass Seedling Establishment

  Frasier, G. W.; Cox, J. R.; Woolhiser, D. A. (Society for Range Management, 1987-01-01)

  A series of 14-day field experiments were conducted to evaluate seedling establishment characteristics of Bouteloua, Erogrostis, and Panicum grass species with controlled wet-dry watering combinations. The objective of the study was to validate previously published greenhouse data of Frasier et al. (1985) on the effects of the first wet-dry watering sequence following planting on seedling emergence and survival. Seedling survival numbers were different between the field and greenhouse experiments but the same general responses to watering sequences were measured. With short wet periods (2 days), seeds generally did not germinate but survived the subsequent dry period as viable seeds. Most seeds germinated with 5 wet days and produced seedlings that were able to survive drought periods of 5 to 7 days. Fewer seedlings survived with 3 days wet than with either 2 or 5 days wet. High rates of soil moisture evaporation in a spring field experiment made it difficult to maintain adequate soil moisture for seed germination, and seeds which germinated failed to produce seedlings. Seedlings were successfully established in 2 experiments conducted later in the summer following the onset of summer rains, which increased the relative humidity and reduced the rate of soil moisture evaporation. This effect was verified in a greenhouse study. In both the greenhouse and field experiments, seedlings were established when the relative humidity exceeded 50% for over one-half of the time during the initial wet-dry period.
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  Variations in Physiological Metabolites and Chlorophyll in Sexual Phenotypes of 'Rincon' Fourwing Saltbush

  Tiedemann, A. R.; McArthur, E. D.; Freeman, D. C. (Society for Range Management, 1987-03-01)

  An experiment was conducted to determine if concentrations of chlorophyll and basic metabolites (total organic nitrogen (TN), total phosphorus (TP), and total nonstructural carbohydrates (TNC)) were an indication of the physiological vigor of the 3 sexual phenotypes of fourwing saltbush (Atriplex canescens (Pursh) Nutt.). Our basic hypothesis was that males, females, and plants capable of male and female sex expression (sexually labile) were equally vigorous as was manifested in chlorophyll and metabolite levels. In June, concentrations of chlorophyll a, b, and total chlorophyll in the male phenotype were greater than in either the female or the labile phenotypes. There were no differences among phenotypes for the other dates. Male plants had the highest levels of metabolites (TN, TP, and TNC) when any differences among sexual phenotypes were significant. There were basically no differences in metabolite concentration between the female and labile sexual phenotypes. Results indicate that part of the hypothesis should be rejected-that male, female, and sexually labile plants are equally vigorous based on concentrations of chlorophyll and metabolites. Part of the hypothesis, however, can be accepted-that females and labile plants are comparable in physiological vigor. Levels of all 3 metabolites showed striking trends among sample dates, which indicated that fourwing saltbush has the capability of rebuilding its levels of metabolites in the spring at the physiologically costly time of flowering. This may be related to the photosynthetic efficiency associated with its C-4 photosynthetic pathway.
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  Variation in Utilization of Big Sagebrush Accessions by Wintering Sheep

  Welch, B. L.; McArthur, E. D.; Rodriguez, R. L. (Society for Range Management, 1987-03-01)

  We observed the effects of accessions of big sagebrush (Artemisia tridentata) on big sagebrush utilization by wintering domestic sheep. The sheep had continuous access to high quality alfalfa hay and were fed 0.28 kg of rolled barley per head per day. Utilization was expressed as a percent of the current year's vegetative growth consumed by the sheep and also as grams of dry matter eaten per stem. Utilization of accessions varied from 0 to 98% over 3 sites and from 0 to 7.112 g of dry matter per stem. The sheep tended to remove significant (60 to 70%) amounts of current growth from the more preferred accessions before removing even small (15%) amounts of less preferred accessions. If this is typical grazing behavior, preferred big sagebrush plants may be lost in areas subject to repeated grazing.
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  Using Leaf Fluorescence for Evaluating Atrazine Tolerance of Three Perennial Warm-Season Grasses

  Bahler, C. C.; Moser, L. E.; Vogel, K. P. (Society for Range Management, 1987-03-01)

  Atrazine [6-chloro-N-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine] blocks photosynthetic electron transport in susceptible plants. The energy from the interrupted electron transport is fluoresced from the leaves of atrazine-treated plants. The purpose of this study was to evaluate leaf fluorescence as a nondestructive bioassay of the relative atrazine tolerance of 3 perennial, warm-season grasses. Leaf section of switchgrass [Panicum virgatum L.] (high tolerance), indiangrass [Sorghastrum nutans (L.) Nash] (intermediate tolerance), and sideoats grama [Bouteloua curtipendula (Michx.) Torr.] (lower tolerance) were placed in distilled water for 20 min and then in atrazine solutions. Fluorescence readings were taken prior to and after the atrazine treatment with a portable fluorometer. The difference between the 2 readings provided a reliable measure with low variability of the relative atrazine tolerance of the grasses studied and was effective on greenhouse-and field-grown plants. Optimum atrazine concentrations and incubation periods were 10^-3 M (atrazine in distilled H2O and 30 min, respectively.
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  Understory Herbage Production of Major Soils within the Black Hills of South Dakota

  Bennett, D. L.; Lemme, G. D.; Evenson, P. D. (Society for Range Management, 1987-03-01)

  Two-year understory production was determined on 6 major forest soils across 2 geomorphic regions in the Black Hills of South Dakota. Stepwise multiple regression was used to determine those variables best explaining yield variability. Canopy cover, basal area, soils, May-June precipitation, and soil × cover interactions further improved the models, which accounted for 65 to 76% of the variability in herbage production. Footslope, nonskeletal soils had the highest herbage production (yielding 1,800 kg/ha at 0% canopy cover). The least developed, backslope, skeletal soil had the lowest herbage production (producing only 550 kg/ha at 0% canopy cover) from comparable areas of the Black Hills. Developed models can be used in conjunction with soil survey reports to estimate the forage potential of a given soil mapping unit. Results from this study emphasize the importance of considering the understory vegetation production potential of individual soil series when developing grazable woodland management plans. Soil-related production differences were most strongly expressed under conditions of limited overstory canopy cover.
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  The Woody Vegetation of Eastern Senegal

  Dickie, A.; Pieper, R. D.; Dickey, J. R. (Society for Range Management, 1987-01-01)

  The woody component of the vegetation of eastern Senegal was sampled using the point-centered quarter method. Data were evaluated using cluster, principal component, and multiple discriminant analysis (MDA) techniques. Sites were grouped into 8 ecologically significant groups. Six of these groups were considered woodland lateritic sites, and 2 drainage sediment sites. Species of the genus Combretum dominated all sites. The effect of livestock grazing on the botanical composition was inferred through the use of 4 environmental variables as discriminant factors in MDA. A floristic record of species composition and guidelines for management are embodied in the results of the analyses.
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  The Use of a Portable Computer for Real-Time Recording of Observations of Grazing Behavior in the Field

  Demment, M. W.; Greenwood, G. B. (Society for Range Management, 1987-05-01)

  A real-time system for recording grazing behavior in the field is described. A NEC 8201a portable computer was programmed to allow the incidence, duration, and sequence of behaviors to be recorded. This system was used in the field to record bites, chews, steps, and swallows of grazing cattle. Data files were analyzed to determine biting, stepping, and swallowing rates as well as bites per feeding station. Durations of all activities can be summarized. This system permits the observer to record accurately feeding behavior and reduce significantly the time and cost of processing data.
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  The Influence of Grazing Pressure on Rooting Dynamics of Caucasian Bluestem

  Svejcar, T.; Christiansen, S. (Society for Range Management, 1987-05-01)

  Caucasian bluestem (Bothriochloa caucasica (Trin.) C.E. Hubb.) is a warm-season grass introduced from Eurasia that is currently used for reseeding farmland and depleted range in the Southern Great Plains. Although this species is thought to be grazing tolerant, little specific information is available concerning its response to grazing. Variable (put-and-take) stocking was used to maintain heavy (3 to 8 steers/ha) and light (2.5 to 4.5 steers/ha) grazing treatments during mid May to late September from 1983 to 1985. Seasonal changes in root mass and root length to a depth of 60 cm were measured the first 2 years, and end-of-season root length was measured the third year. Leaf area index (LAI) was measured during the first 2 years. Peak root mass was 27 and 46% less in heavily relative to lightly grazed swards in 1983 and 1984, respectively. Total root length for heavily grazed swards was 33 and 45% less than lengths of lightly grazed swards in 1983 and 1984, respectively. Heavy grazing resulted in a relatively larger reduction in LAI than in either root mass or length, and thus the ratio of absorbing root surface to transpiring leaf surface was greater for heavily grazed than lightly grazed plants. This increased ratio may explain our previous observation that heavy grazing resulted in an improved water status of leaf tissue. End-of-season total root length over the 3-year period (15 to 18 and 24 to 28 km/m2 for heavily and lightly grazed swards, respectively) was remarkably consistent given the variable climatic conditions over the study period.
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  Temperature and Scarification Effects on Germination of Prostrate Bundleflower Seeds

  Fulbright, T. E.; Flenniken, K. S. (Society for Range Management, 1987-03-01)

  A hard seed coat restricts germination of prostrate bundleflower [Desmanthus virgatus var. depressus (Humbolt and Bonpland ex Willd.) Turner] seeds. Our objectives were to determine: (1) the effects of temperature on germination of scarified and untreated seeds in the light and dark and (2) the efficacy of various presowing treatments in increasing germination. Scarified (nicked with a razor blade) and untreated seeds were germinated at 5-15, 10-20, 15-25, 20-30, 25-35, and 30-40 degrees C (12 hours - 12 hours) in the dark or with light during the warmer temperature. Effects of scarification with 17 M H2 SO4, hot (80 degrees C) water, 0.7 mol liter-1 NaOCl, 2.9 mol liter-1 H2O2, and nicking with a razor blade on germination were compared. Maximum germination of untreated seeds was only 6%. Germination of scarified seeds exceeded 90% at 15-25 degrees C and higher temperatures. Light did not affect germination at optimal temperatures for germination. Nicking seeds with a razor blade, soaking 40 minutes in 17 M H2 SO4, and soaking 25 minutes in hot (80 degrees C) water resulted in 91, 88, and 78% germination, respectively, compared to 3% for controls. Our results indicated that, for best germination, seeds should be soaked 40 minutes in 17 M H2 SO4 or nicked with a razor and planted when mean minimum-maximum soil temperatures exceed 15-25 degrees C.
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  Technical Notes: Survival Analysis of Single and Twin Lambs

  Scrivner, J. H.; Dally, M. R.; Howard, W. E. (Society for Range Management, 1987-03-01)

  We illustrate the use of life tables and survival analysis for evaluating data on livestock losses. The techniques are used to compare the rate of coyote (Canis latrans) predation on single and twin lambs. Based on the number of lambs known to have been killed by predators, the survivorship of single and twin lambs was not significantly different (P>0.05) for any year of the study. Survival functions which can be generated and used to evaluate data on livestock losses include the cumulative proportion of livestock surviving at the end of an interval, probability density, and hazard rate.
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  Succession of Pinyon-Juniper Communities After Mechanical Disturbance in Southcentral New Mexico

  Schott, M. R.; Pieper, R. D. (Society for Range Management, 1987-01-01)

  Principal component analysis (PCA) was used to interpret secondary succession of pinyon-juniper stands after cabling or bulldozing. Soil types were used to separate 93 sample units into 3 groupings. A PCA was run on 2 of the groupings. Groups of sample units were defined as community types for each ordination. Stepwise discriminant analysis using environmental variables was used to assist in delineation of community types. Species that contributed the most to the first 3 principal components were compared among community types for each ordination using an analysis of variance and a comparison of the least squares means. Grasses on the deeper soils usually increased after cabling, but after 25 years they had declined to near pretreatment levels. Wavyleaf oak (Quercus undulata Torr.) increased after cabling, and on the older cablings it had reached higher cover values than on the other community types. Pinyon and juniper response appeared to be dependent on density and size of trees before cabling. If the stand was near climax before cabling, pinyons rapidly became dominant on the site. If it was seral, there would be more junipers, but their slow growth and the time they require for maturation required more time before they dominated the site. The successional pattern following cabling on relatively deep soils is similar to what was found after fire, but it occurs faster. Cover of grasses and shrubs increased more on rock-free soils compared to sites treated similarly but with rock. The ordinations indicated that succession in pinyon-juniper communities is directional and leads towards climax with a decrease in variability among sites.
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  Subterranean Clover on Southern Pine Range: Potential Benefits to Game

  Ribbeck, K. F.; Johnson, M. K.; Dancak, K. (Society for Range Management, 1987-03-01)

  Wildlife habitat is an important component of forested lands in the South. We examined effects of silvicultural practices and understory management on abundance of arthropods for wild turkey (Meleagris gallopavo) and bobwhite (Colinus virginianus). Plots (roughtly equal to 0.1 ha) of southern pine timber (25-35 years old) were thinned or cleared and were planted with subterranean clover (Trifolium subterraneum) or were allowed to produce native vegetation. Arthropods were most abundant in clearings for both understory treatments: 127 +/- 15 (subterranean clover), 45 +/- 5 (native) per plot. Abundance of arthropods on pine forested plots with a subterranean clover understory was often greater than abundance of arthropods on cleared plots with native vegetation. Many of the arthropods sampled were the kinds often used by wild turkey and bobwhite. Subterranean clover production on forested plots was about 70% of production on cleared plots. Arthropods from 5 of 8 orders were significantly (P<0.05) more abundant in subterranean clover plots compared to native vegetation. Abundance of arthropods was significantly (P<0.05) associated with forage yield. Dead subterranean clover provided more arthropods in summer than live native vegetation. Planting subterranean clover in Southern pine timber offers a good alternative to removal of timber production for improving wildlife habitat and for integrating livestock and game management practices. Costs for establishing (roughly equal to $100/ha) and maintaining (roughly equal to $50/ha/yr) subterranean clover under pine timber are less than the potential loss in timber revenue ($125 to 340/ha/yr) associated with maintaining clearings.
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  Shrub Litter Production in a Sagebrush-Steppe Ecosystem: Rodent Population Cycles as a Regulating Factor

  Parmenter, R. R.; Mesch, M. R.; MacMahon, MacMahon. J. A. (Society for Range Management, 1987-01-01)

  This study examines the impact of long-tailed vole (Microtus longicaudus) and deer mouse (Peromyscus maniculatus) population changes and their feeding behavior on shrub populations and the resulting litter production in a shrub-steppe ecosystem in southwestern Wyoming. Rodent populations were monitored on 3 replicate plots over a 3-yr period. Populations peaked in autumn 1983 and declined to lower levels in 1984-86. Damage to shrubs (in the form of bark-stripping and girdling) was observed after the winter of 1983-84, but not after the winters of 1984-85 and 1985-86. We assessed damage to shrubs on 4 sites. Extent of damage, mortality, and biomass-to-litter transformations were quantified. We found that: (1) 21% of all shrubs and 28% of the big sagebrush (Artemisia tridentata) sustained rodent damage; (2) 1% of all shrubs were killed as a result of girdling; (3) mean biomass lost from shrubs that suffered damage was 36%; (4) total aboveground biomass loss occurring on big sagebrush was 231 kg/ha or 4% of the standing crop. These results indicate that rodents feeding on big sagebrush can periodically increase annual rates of litter production by as much as 69% above "normal." Rodents in the sagebrush-steppe ultimately influence ecosystem-level nutrient cycles by accelerating shrub litter production, and may affect plant species composition via feeding-induced shrub mortality.

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