• Tall Larkspur: Some Reasons for Its Continuing Preeminence as a Poisonous Plant

      Cronin, E. H. (Society for Range Management, 1971-07-01)
      Tall larkspur (Delphinium barbeyi Huth) causes more financial loss than all other poisonous plants growing on the Wasatch Plateau of Central Utah. It is found in the subalpine zone above 9,500 ft and is only locally abundant on a small portion of this area. Dense stands of tall larkspur occur mainly on sites where deep snowdrifts accumulate during the winter. Plants in the communities on these snowdrift areas remain tender, succulent, and green while the palatability of plants on the surrounding areas declines with increased maturity. This differential palatability limits the effectiveness of livestock management to reduce losses. Control of tall larkspur must be selective. Adequate vegetative cover must remain to protect sites which are predisposed to erosion. The survival capacity of tall larkspur indicates the need for surveillance schedule and provisions for retreating plants not killed by previous treatments.
    • Tallgrass Prairie Plant Community Dynamics Along a Canopy Cover Gradient of Eastern Redcedar (Juniperus virginiana L.)

      Limb, Ryan F.; Engle, David M.; Alford, Aaron L.; Hellgren, Eric C. (Society for Range Management, 2010-11-01)
      North American grasslands make up less than 75% of their historic pre-European settlement area, and they continue to be converted to woodlands by woody plant encroachment. Conversion of grassland to woodland alters nutrient cycling, water use, and light penetration, which drives herbaceous plant community dynamics. Because studies examining this relationship among Juniperus species are limited largely to individual trees, we designed a study to examine the relationship between stand-level canopy cover of eastern redcedar (Juniperus virginiana L.) and the herbaceous plant community. We documented herbaceous plant species composition, abundance, and biomass within a North American tallgrass prairie invaded by eastern redcedar in which canopy cover of eastern redcedar ranged from 0% to 80%. Herbaceous species richness declined as a function of increased canopy cover of eastern redcedar and subsequent loss of open space, but this decrease in species richness closely followed a species-area model. Moreover, composition of C3 and C4 grasses and forbs did not change with increasing canopy cover. Herbaceous biomass, which declined with increasing canopy cover, varied most within those plots with intermediate canopy cover. While we found that species richness and biomass declined as canopy cover increased, the decline followed a species-area relationship and was without abrupt change typical of ecological thresholds. We recommend additional research with removal of eastern redcedar trees over a range of canopy cover to assess restoration potential along the encroachment gradient. 
    • Tallgrass prairie response to grazing system and stocking rate

      Gillen, R. L.; McCollum, F. T.; Tate, K. W.; Hodges, M. E. (Society for Range Management, 1998-03-01)
      Grazing system and stocking rate effects on standing crop of species and relative species composition of tallgrass prairies in north-central Oklahoma were evaluated from 1989 to 1993. Twelve experimental units, consisting of pastures dominated by big bluestem [Andropogon gerardii Vitman], little bluestem [Schizachyrium scoparium (Michx.) Nash], and indiangrass [Sorghastrum nutans (L.) Nash], were arranged in a completely randomized design with either a short duration rotation or continuous grazing system and stocking rates ranging from 51.5 animal-unit-days/ha (AUD/ha) to 89.8 AUD/ha. Yearling steers grazed the pastures from late April to late September. Cumulative precipitation was above average during the study period. Continuous and rotation grazing affected the major herbage components similarly over time. Standing crop of all major herbage components declined as stocking rate increased. The standing crop of the major herbage components also declined from the first to the last year of the study. The decrease in standing crop of big bluestem, indiangrass and forbs over years was greatest at lighter stocking rates. Relative composition of switchgrass [Panicum virgatum L.] increased at the lower stocking rates over time in both grazing systems. The relationship between shortgrasses and stocking rate was different between grazing systems at the start of the study but became similar between grazing systems over time. After 5 years, short-grasses were positively related to stocking rate under both grazing systems. Favorable growing conditions and the high seral state of the vegetation in the experimental pastures may have tempered the response to grazing treatments.
    • Tallgrass prairie vegetation response to spring burning dates, fertilizer, and atrazine

      Mitchell, R. B.; Masters, R. A.; Waller, S. S.; Moore, K. J.; Young, L. J. (Society for Range Management, 1996-03-01)
      Tallgrass prairies provide an important source of hay and summer forage in eastern Nebraska. A study was conducted in 1989 and 1990 on 2 late seral tallgrass prairies near Lincoln and Virginia, Nebraska to determine if production of selected components of tallgrass prairie communities could be altered by burning (not burned, or burned in either early, mid-, or late spring)and applying fertilizer (0 and 67-23 kg N-P ha-1) and atrazine [6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine] (0 and 2.2 kg a.iha-1). Vegetation was harvested the year treatments were applied at about 30-day intervals starting in June and ending in August. Maximum big bluestem (Andropogon gerardii var. gerardii Vitman) accumulated standing crop (ASC) on unburned areas and areas burned in mid-spring occurred later in 1990 than in 1989. Burning in late spring 1989 maintained big bluestem ASC above 1,100 kg ha-1 through July, whereas big bluestem ASC declined below 840 kg ha-1 in July on areas where other burn treatments were applied. In 1990, big bluestem ASC exceeded 1,570 kg ha-1 in June on areas burned in early and midspring and exceeded 1,500 kg ha-1 in July on areas that were not burned or burned in mid- or late spring. From July to August 1990 big bluestem ASC declined below 730 kg ha-1 for all treatments except the late spring burn treatment where ASC was 1,340 kg ha-1. Burning in late spring reduced prairie dropseed [Sporobolus heterolepis (A. Gray) A. Gray] and tall dropseed [S. asper (Michx.) Kunth.] ASC by at least 67% in June 1990 compared to areas burned in early and mid-spring. Cool-season grass ASC at Virginia declined 86% in June when burned in late spring compared to areas that were not burned. Fertilization increased big bluestem ASC by about 23 and 29% in June and July. Vegetation response to atrazine was variable. Atrazine had a negligible effect on big bluestem ASC. Burning late seral tallgrass prairie in late spring increased big bluestem ASC later in the growing season and decreased cool-season grasses more effectively than burning earlier in the spring.
    • Tannin and in vitro digestibility of tropical browse: predictive equations

      Conklin, N. L. (Society for Range Management, 1994-09-01)
      Summative equations to predict digestibility of tropical browse species for cattle were tested by comparison to in vitro digestibility. Four equations were used for the comparison: first the 2 Van Soest equations, 1 using sulfuric acid lignin and the other using permanganate lignin, neither of which have a correction for tannins. And second, the 2 Horvath equations, each using 1 of the 2 above mentioned lignin values and both include a value for tannin content. The Van Soest equation using permanganate lignin and the Horvath equation using sulfuric acid lignin predicted the in vitro digestibilities of the leaf species quite well (r = 0.89 for both). The same Horvath equation predicted the digestibility of the high tannin species better than the Van Soest equation (r = 0.93 versus 0.84). For initial evaluation and ranking of browse species suitable for future research efforts, either equation suitable.
    • Tannin chemistry in relation to digestion

      Hagerman, A. E.; Robbins, C. T.; Weerasuriya, Y.; Wilson, T. C.; McArthur, C. (Society for Range Management, 1992-01-01)
      Tannins are a diverse group of compounds which precipitate protein. The impact of tannins on herbivory has been difficult to assess because of diversity in tannin chemistry and in animal physiology. We have evaluated the effects of tannin on large ruminants (deer, sheep) using artificial diets containing well-defined tannins, and have compared the results to those obtained with natural forages. The different effects of condensed tannins and gallotannins on herbivores are related to the chemical stability of the tannins. Commercial tannic acid does not have the same effects on herbivores as gallotannins in natural forages. Molecular weight apparently determines the metabolic fate of gallotannins from various sources.
    • Targeted Grazing of White Locoweed: Short-Term Effects of Herbivory Regime on Vegetation and Sheep

      Goodman, L. E.; Cibils, A. F.; Lopez, S. C.; Steiner, R. L.; Graham, J. D.; McDaniel, K. C.; Abbott, L. B.; Stegelmeier, B. L.; Hallford, D. M. (Society for Range Management, 2014-11)
      White locoweed (Oxytropis sericea Nuttall) and nontarget vegetation response to 2 yr of targeted grazing by sheep, one treatment of picloram plus 2, 4-D (HER) or no treatment (CON) were compared. Serum of sheep that grazed locoweed intermittently (IGZ, 5 d on locoweed followed by 3 d off locoweed) vs. counterparts that grazed locoweed continuously for 24 d (CGZ) was also examined. Alkaloid toxicity was inferred by serum levels of thyroxine (T4), triiodothyronine (T3), alkaline phosphatase (ALKP), aspartate aminotransferase (AST), and swainsonine, as well as behavior and body weight gains. Three sites were used in a randomized complete block design. IGZ, CGZ, and HER treatments reduced locoweed density (P < 0.01), canopy cover (P < 0.01), number of flower stalks (IGZ: P = 0.02, CGZ and HER: P = 0.01), and plant size (P < 0.01). White locoweed seed density in the soil seed bank was not reduced with grazing, and nontarget vegetation was mostly unaffected by treatments. Grass canopy cover increased in grazed and herbicide plots throughout the study (IGZ: P = 0.03, CGZ and HER: P < 0.01). Percentage bare ground was unchanged (IGZ: P = 0.46, CGZ: P = 0.44) in grazed plots but decreased (P = 0.03) in HER plots. After 24 d, ewes in the IGZ treatment had lower levels of serum ALKP (P < 0.01) and AST (P = 0.02) and marginally lower swainsonine levels (P < 0.07) than CGZ ewes that tended to exhibit lower serum T3 (P < 0.07) and similar serum T4 (P = 0.25) levels. Time spent feeding on locoweed tended to differ (P = 0.06) between treatments. Body weight gain was the same (P = 0.19) regardless of treatment. IGZ of locoweed-infested rangeland with sheep may be a viable short-term means of reducing locoweed density without detrimentally affecting animal health. © 2014 Society for Range Management
    • Taxonomic and Agronomic Variation in Agropyron spicatum and Agropyron inerme

      Chapman, S. R.; Perry, L. J. (Society for Range Management, 1973-01-01)
      The main morphological distinction between bluebunch wheatgrass and beardless wheatgrass is the presence of geniculate awns in the former and the absence of awns in the latter. Open pollinate progenies of plants classified as either A. spicatum or as A. inerme segregated clearly for this trait. This indicates the mere presence or absence of awns does not afford reproductive isolation; thus, the species designation is questionable. In addition, variation for rhizomes was detected in the progenies of bunch type plants, but segregation was not clear cut. Significant variation among progeny means for forage yield was also detected. There is apparent, real potential for varietal development, but care must be exercised in mixing awned and awnless types.
    • Taxonomic Determination, Distribution, and Ecological Indicator Values of Sagebrush within the Pinyon-Juniper Woodlands of the Great Basin

      West, N. E.; Tausch, R. J.; Rea, K. H.; Tueller, P. T. (Society for Range Management, 1978-03-01)
      Various sagebrush taxa are major understory components of most Great Basin pinyon-juniper woodlands. Improved understanding of their identification, distribution, and ecological indicator significance is necessary to interpret site differences for these ranges. Morphology within sagebrush taxa is so variable that chromatographic determination is more easily and objectively relied upon for identification. Big sagebrush is so widespread and likely genetically diverse that sub-specific designations are more helpful in reading site conditions. The various sagebrush taxa are found in particular situations in Great Basin woodlands. Climatic differences explain the basin-wide distributions much more than geologic, landform, or soil conditions. Soils and exposure become more important on the local scale. Presence of a particular sagebrush taxon within pinyon-juniper woodlands can be used for comparisons of site favorableness provided one understands the general distribution of the other sagebrush taxa.
    • Teaching Range Facts—The Role of the Schools

      Young, V. A. (Society for Range Management, 1951-09-01)
    • Teaching Tomorrow's Ranchers Today

      Wilson, D. (Society for Range Management, 1955-09-01)
    • Technical Assistance in Agricultural Development

      Drosdoff, M. (Society for Range Management, 1966-11-01)
    • Technical note: A comparison of techniques for extracting monoterpenoids from Juniperus (Cupressaceae) species

      Owens, M. K.; Straka, E. J.; Carroll, C. J.; Taylor, C. A. (Society for Range Management, 1998-09-01)
      Concentration and composition of monoterpenoids in plant tissue affects a variety of environmental and ecological issues such as plant defenses, plant classification and phytotoxicity. Developing the techniques for extracting and estimating the concentration and composition of monoterpenoids must be species-specific because monoterpenoid storage location varies between species. Ashe juniper (Juniperus ashei Buchholz) and redberry juniper (J. pinchotti Sudw) are 2 co-occurring species which differ in palatability and preference. The objective of this study was to determine which of 2 common extraction techniques provided the best estimate of the concentration and composition of monoterpenoids in mature plant tissue. Two extraction techniques were tested by soaking crushed juniper needles in hexane solvent for 6, 12, 18 and 24 hours or by steam distilling samples for 2, 4, 6, or 8 hours. The extracts were analyzed by using 2 different analytical columns in separate gas chromatographs. The hexane solvent soak, regardless of time in the solvent yielded a lower total concentration and a decreased compositional diversity of monoterpenoids compared to the steam distillation technique. An 8-hour steam distillation yielded the greatest concentration and composition of monoterpenoids. Both types of analytical columns resulted in similar estimates of monoterpenoid concentrations and composition.
    • Technical Note: A containerized technique for studying root systems

      Engel, R. K.; Nichols, J. T.; Brummer, J. E. (Society for Range Management, 1993-09-01)
      Quantifying root responses of naturally growing range plants to treatments is difficult. The objective of this study was to develop a containerized technique to study individual plants growing in the field under near natural environmental conditions. Three containers were evaluated: 15 X 100 cm nylon (2,000 pores/cm2) sacks, 15 X 100 cm polyvinyl chloride (PVC) tubes, and 30 X 100 cm PVC tubes. The 15 X 100 cm PVC tubes were easiest to handle, and plants grown in these containers appeared similar in size and growth form to adjacent, undisturbed plants. Survival rate for 165 sand bluestem (Andropogon hallii Hack.) plants grown for 2 years in the 15 X 100 cm PVC tubes was 98.8%. This survival rate was achieved despite clipping treatments during the second year.
    • Technical Note: A rotary seed processor for removing pubescence from seed of prairie grasses

      Vogel, K. P.; Masters, R. A.; Callahan, P. J.; Grams, K. (Society for Range Management, 1998-09-01)
      Many of the perennial prairie grasses that are used in restoration plantings in the central Great Plains have seed appendages such as awns and pubescence that make seed now through planters difficult. We have developed a rotary seed processor that efficiently processes small breeder or experimental lots of seed that can then be easily planted with small plot cone planters or conventional planters. The processor consists of a metal cylinder that is lined with corrugated rubber and a rotating center shaft with rubber paddles. Processing can be controlled by varying shaft rotation speed and processing time. A top-opening, full length trap door allows for easy loading and the cylinder can be inverted to dump out processed seed. The processor has been used successfully for several years on big bluestem [Andropogon gerardii Vitman], indiangrass [Sorghastrum nutans (L) Nash], little bluestem [Schizachyrium scoparium (Michaux) Nash], prairie sand reed [Calamovilfa longifolia (Rook.) Scribner] , and blue grama [Bouteloua gracilis (Willd. ex Kunth) Lagascaex Griffiths] seed. By removing seed appendages and pubescence, seed bulk is reduced and seed density and flow ability are improved. The processing operation is relatively gentle and seed germination per unit weight of seed is improved.
    • Technical Note: A simple method for preparing reference slides of seed

      Dacar, M. A.; Giannoni, S. M. (Society for Range Management, 2001-03-01)
      Microhistological analysis has become the most commonly used and successful method for determining micromammal diets. However, this technique has a number of limitations, particularly when used on fecal samples where identification of some items is difficult. This method underestimates those nearly unrecognizable plant parts in the diet, such as seed, and overestimates easily identifiable parts, such as leaf epidermis. In this note we describe a simple technique that uses a macerating solution of 17.5% NaHCO3 for preparing reference slides of seeds. Advantages of the proposed method are discussed and compared with Jeffrey's technique.
    • Technical note: a technique for conducting small-plot burn treatments

      Korfmacher, J. L.; Chambers, J. C.; Tausch, R. J.; Roundy, B. A.; Meyer, S. E.; Kitchen, S. (Society for Range Management, 2003-05-01)
      An experimental design required burn treatments for 10-m2 circular plots. We constructed a fire enclosure for the plots using sheetmetal, electrical conduit, and other commonly available materials. We field tested the enclosure in sagebrush-grass ecosystems in central Nevada and central Utah, and evaluated peak fire temperatures using small metal tags striped with temperature sensitive paint. We obtained average peak surface temperatures of 310, 307, and 381 degrees C in bare ground, under grass, and under shrub microsites, respectively, for the Nevada sites and 253, 299, and 337 degrees C for the same microsites, respectively, in Utah. Subsurface (2-cm depth) temperatures rarely exceeded 79 degrees C, the lowest temperature detectable by our method. The enclosure contained the fire and did not permit escape of any embers or firebrands. The fire enclosure, burn technique and temperature monitoring method used are inexpensive, easily deployed, and desirable for experiments where larger-scale burns are impractical.
    • Technical Note: A total urine collection apparatus for female bison and cattle

      Deliberto, T. J.; Urness, P. J. (Society for Range Management, 1995-01-01)
      A urinary collection device is described for use in metabolism studies on female bison (Bison bison) and cattle. Separating urine from feces, and collecting all urine produced by female animals in metabolism stalls present difficulties. Catheters are usually used on animals in confinement, but often with varying degrees of success. Thus, an external device designed to divert urine into collection receptacles was developed. The urine collection apparatus was used successfully in six 8-day metabolism trials conducted during 1991 and 1992.
    • Technical Note: An evaluation of 4 clovers and Italian ryegrass for white-tailed deer

      Johnson, M. K.; Schultz, S. R. (Society for Range Management, 1992-11-01)
      We evaluated winter weight gain of captive male white-tailed deer (Odocoileus virginianus) that grazed pastures of berseem (Trifolium alexandrinium L.), white (T. repens L.), crimson (T. incarnatum L.), or subterranean (T. subterraneum L.) clover their first winter and pastures of berseem, white, or crimson clover or Italian ryegrass (Lolium multiflorum Lam.) their second winter. Weight gains the first winter (14.7 +/- 0.7kg) did not differ (P>0.10) among the clovers. Bucks that grazed berseem, white, or crimson clover the second winter gained 3.0 +/- 0.5 kg, while bucks that grazed Italian ryegrass gained 0.9 +/- 0.9 kg.