bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxalate and tannins assessment in Atriplex halimus L. and A. nummularia L
Authors: Abu-Zanat M. M. , Al-Hassanat F. M. , Alawi M. ,   Society for Range Management
Published: March 2016

The study was conducted at 3 locations in the arid region of Jordan to assess the seasonal changes of oxalate and tannins in Atriplex halimus L. and A. nummularia L. plants commonly used for revegetation of degraded rangelands. During spring and fall seasons, 20 shrubs of each species were selected randomly at each location, 20 similar twigs per shrub were clipped and analyzed for oxalate and tannins. Atriplex halimus contained higher levels of oxalate (7.00%) compared with A. nummularia plants (6.20%) (P < 0.001). Oxalate levels averaged 8.29 and 4.92% in spring and fall season, respectively. Plants of A. halimus accumulated more oxalate in spring than those of A. nummularia. Clipping had no effect on oxalate concentration. The seedlings of A. nummularia contained more oxalate than old plants whereas old shrubs of A. halimus contained more oxalate than the young seedlings. The browse of A. halimus contained more condensed and hydrolyzable tannins (1.05% and 0.67%, P < 0.0001) than A. nummularia (0.80% and 0.39%, P 0.0001), respectively. Clipping had no effect on the levels of tannic phenols, condensed and hydrolyzable tannins. Young plants of the 2 species had higher levels of condensed tannins compared to older plants. However, seedlings of A. nummularia contained significantly higher levels of condensed tannins compared to A. nummularia seedlings (1.57% and 1.47%, respectively). Atriplex halimus synthesized more oxalate, tannic phenols, condensed and hydrolyzable tannins than A. nummularia. These secondary metabolites may explain the low palatability of Atriplex halimus compared to A. nummularia.
Journal of Range Management, Volume 56, Number 4 (July 2003)
Authors:   Society for Range Management
Published: March 2016

Complete digitized issue.
Defoliation impacts on Festuca campestris (Rydb.) plants exposed to wildfire
Authors: Bogen A. D. , Bork E. W. , Willms W. D. ,   Society for Range Management
Published: March 2016

Wildfires commonly occur in the Fescue Prairie of Alberta, but little information exists to provide a basis for making grazing recommendations after burning. A wildfire in April 1999 provided an opportunity to study the effect of season and intensity of post-burn defoliation on foothills rough fescue (F. campestris Rydb.) in southwestern Alberta. A 3 (date of defoliation) x 2 (defoliation intensity) factorial experiment with 10 replicates (plants) was established in both a burned and a non-burned grassland and analyzed as a nested design. Plants were defoliated once during active vegetative growth (17 May), inflorescence development (2 July), or dormancy (30 September), at either 5 or 15-cm clipped stubble heights in the first growing season after fire. Burning increased tiller numbers by 54% compared to non-burned plants but reduced plant ANPP by 51% in the second growing season. While a single defoliation of burned plants, particularly early in the year, had little effect on growth, delaying defoliation into July decreased tillers 1 year later. Increasing defoliation intensity had the greatest impact on non-burned plants, reducing plant height (15%) as well as tiller (21%) and plant (32%) ANPP in the second year. May defoliation reduced etiolated growth 1 year later regardless of burn treatment. A single grazing event after wildfire does not necessarily appear to detrimentally affect rough fescue; however, the low herbage available immediately after fire may not justify the increased risk to the plant with subsequent grazing.
The economic logic of prescribed burning law and regulation
Authors: Yoder J. , Engle D. M. , Tilley M. ,   Society for Range Management
Published: March 2016

Prescribed burning has long been recognized as a useful tool in rangeland management, but with it comes the risk of fire and smoke damage to the property of others. All but 2 states have codified laws specifying criminal penalties or liability rules for prescribed burning, but the laws in a number of states have changed in recent years or are under review. We develop an economic model of the incentive and welfare effects of prescribed burning law and regulation in which the likelihood and extent of external damage can be reduced by precautionary effort on the part of both the burner and/or the victim. The model provides implications regarding the comparative advantages to the public of strict liability versus negligence rules. We conclude that the relative effectiveness of a liability rule depends in large part on the relative ability of burners and other landowners to mitigate the probability and extent of damage, as well as the legal costs associated with implementing a given liability rule.
Journal of Range Management, Volume 56, Number 5 (September 2003)
Authors:   Society for Range Management
Published: March 2016

Complete digitized issue.
Wyoming big sagebrush seed production from mined and unmined rangelands
Authors: Booth D. T. , Bai Y. , Roos E. E. ,   Society for Range Management
Published: March 2016

Wyoming Coal Rules and Regulations require shrubs be returned to mined land and that revegetation "...be self renewing." We evaluated seed production and seed quality of Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis (Beetle Young)) by measuring the effect of mining, herbivory, and environmental modification on seed production at 5 sites on the Dave Johnston Coal Mine near Glenrock, Wyo. Mined-land stands ranged in age from 5 to >20 years. Single sagebrush plants on mined, and adjacent unmined land were treated by: (1) fabric mulch around the base, (2) windbreak on the north and west, (3) both mulch and windbreak, and (4) neither windbreak nor mulch. Plants were fenced and compared with unfenced, untreated, neighboring plants. Seeds were harvested for 3 years and data were collected on seed-stalk numbers, bulk weight of seeds produced, and seed quality. Fenced mined-land plants produced several times more seeds than fenced plants on adjacent unmined land. There was no difference in seed quality. Treatments to modify the plant environment resulted in some benefits but fencing had a greater effect on seed-quality parameters than did planned treatments. We conclude the sagebrush seed-production potential on reclaimed lands such as those of the Dave Johnston Coal Mine is equal to, and often several times greater than that of adjacent unmined lands. However, browsing by wild ungulates can eliminate the mined-land yield advantage.
Research observation: Hydrolyzable and condensed tannins in plants of northwest Spain forests
Authors: González-Hernández M. P. , Karchesy J. , Starkey E. E. ,   Society for Range Management
Published: March 2016

Tannins are secondary metabolites that may influence feeding by mammals on plants. We analyzed hydrolyzable and condensed tannins in 30 plant species consumed by livestock and deer, as a preliminary attempt to study their possible implications on browsing and grazing in forest ecosystems. Heathers (Ericaceae) and plants of the Rose (Rosaceae) family had tannins, while forbs, grasses and shrubs other than the heathers did not show astringency properties. We found the highest tannin content of all the species in Rubus sp., with the highest value around 180 mg TAE/g dry weight in spring. Potentilla erecta, Alnus glutinosa and Quercus robur were next with 57 to 44 mg TAE/g dw. Total tannins in heathers ranged from 22 to 36 mg TAE/g dw. Levels of condensed tannins were higher than hydrolyzable for most of the species. Only Betula alba, Calluna vulgaris, Pteridium aquilinum and Vaccinium myrtillus had 100% hydrolyzable tannins. Tannin content of the species changed seasonally with highest values during the growing season, corresponding to late winter or early spring, depending on the species.
Observations of cattle use of prairie dog towns
Authors: Guenther D. A. , Detling J. K. ,   Society for Range Management
Published: March 2016

We investigated the use of prairie dog towns by cattle (Bos taurus) on the shortgrass steppe of northeastern Colorado by conducting surveys of cattle and vegetation from June to August 1999. Cattle presence and behavior were recorded 3 times a week during driving surveys of 15 black-tailed prairie dog (Cynomys ludovicianus) towns. A subset of 3 pastures with prairie dog towns was intensively surveyed twice weekly wherein the habitat and activity of a randomly chosen focal animal was recorded every 6 minutes for 3.5 hours. Bite and step counts of other individuals were recorded for 5-minute intervals. Vegetation height and cover data were collected monthly on each of 6 habitats. Results from driving surveys and intensively surveyed pastures were similar; cattle neither significantly preferred nor avoided prairie dog towns. Bare ground cover on prairie dog towns did not significantly differ from most other habitats, but vegetation on prairie dog towns was significantly shorter on (mean = 6.7 cm) than that off (mean = 11.9 cm) prairie dog towns. Nevertheless, foraging observations indicated that there was no significant difference between cattle foraging rates on swales (70.9 bites/min) and prairie dog towns (69.5 bites/min). Thus, cattle on the shortgrass steppe appear to use prairie dog towns in proportion to their availability and, while there, they graze as intensively as they do on habitats not inhabited by prairie dogs.
Water, nitrogen and ploidy effects on Russian wildrye mineral concentrations
Authors: Karn J. F. , Frank A. B. , Berdahl J. D. ,   Society for Range Management
Published: March 2016

High quality forage for spring and autumn grazing can be obtained from Russian wildrye [Psathyrostachys juncea (Fisch.) Nevski], a cool-season bunchgrass. However, little is known about mineral concentrations critical to livestock production, especially in the relatively new tetraploid plants. A knowledge of plant mineral concentrations and how they can be manipulated to more nearly meet animal requirements is necessary to optimize animal production. A study was undertaken to determine the extent that concentrations of critical minerals in leaf and stem tissue of Russian wildrye were affected by ploidy level, growing-season water (50 and 150% of average), and N fertilizer (10 and 134 kg N ha-1). Plants were sampled at vegetative, boot, anthesis, and anthesis plus 10-day stages of maturity in 1994, 1995, and 1996. Ploidy level resulted in small but significant differences in some mineral concentrations, with diploid plants usually having higher levels. An exception was P in stem tissue. This finding indicates that in breeding and selection for other traits, forage quality was not adversely affected. Growing-season water level also had minimal effects on mineral concentrations, except for P which was enhanced (P < 0.05) by greater amounts of soil water. Fertilizer N increased forage levels of Ca, K, Cu, and Zn, and decreased levels of P. Higher concentrations of K are not desirable, because they increase the possibility of a grass tetany problem. Advancing plant maturity caused a decrease in P and Zn concentrations, but Ca and Mg in leaf tissue increased as plants matured. These results suggest that concentrations of P, Ca, Mg, and Cu were marginal for high producing cattle at some stages of maturity, but we found the effects of nitrogen and growing-season water did not result in leaf and stem mineral concentration changes that would adversely affect the safety and nutritive quality of Russian wildrye.
Comparison of 2 techniques for monitoring vegetation on military lands
Authors: Prosser C. W. , Skinner K. M. , Sedivec K. K. ,   Society for Range Management
Published: March 2016

The U.S. Army is responsible for preparing a well-trained combat force while maintaining the ecological diversity and integrity of the lands it manages. The ability to efficiently collect data that accurately capture plant community diversity and percent composition is imperative to proper monitoring and land management of military lands. To ensure that the dual goals of military training and land stewardship are met on an army-wide basis, the U.S. Army Land Condition-Trend Analysis (LCTA) Program was developed. The LCTA Program specifies the Army's standard methodology for the collection, analysis, and reporting of natural resource data used for land inventory and monitoring. However, the LCTA sampling technique was developed in Colorado and Texas and little information is available on whether these methods are suitable for vegetation inventory and monitoring in other grassland ecosystems. This study compares LCTA measures of species richness and composition with quadrat sampling in the transitional area between the tall- and mixed-grass prairies of Camp Gilbert C. Grafton (South Unit) in North Dakota. Species richness was 67% higher when sampling with quadrats than using the LCTA technique, suggesting that LCTA samples did not detect a third of the plants present. Compared with the quadrat technique, LCTA samples overestimated the community contribution of Bouteloua gracilis (H.B.K.) Lag. ex Steud. (blue grama) and underestimated proportions of forbs and sedges. Moreover, LCTA samples are labor intensive and time consuming to collect. Other sampling methods may be needed to detect shifts in species composition towards a less desirable plant community or decreases in biodiversity that may be due to land-use. Thus, it is important for Camp Gilbert C. Grafton (South Unit) to re-evaluate the current standard methodology for monitoring the impacts of military training. Since military installations are located in many different ecosystems, it may be necessary for other installations to likewise examine the usefulness of LCTA techniques in their ecosystems.
Economic implications of off-stream water developments to improve riparian grazing
Authors: Stillings A. M. , Tanaka J. A. , Rimbey N. R. ,   Society for Range Management
Published: March 2016

Livestock grazing in riparian areas is an important management issue on both private and public lands. A study was initiated in northeastern Oregon to evaluate the economic and ecological impacts of different cattle management practices on riparian areas. The effect of off-stream water and salt on livestock distribution and subsequent impact on riparian use, water quality, and livestock production was evaluated. A multi-period bioeconomic linear programming model is used to evaluate the long-term economic feasibility of this management practice with a riparian utilization restriction of 35% for a 300 cow-calf operation. The utilization restriction resulted in economically optimal herd sizes 10% smaller than the baseline herd size. With the management practice, cattle were distributed more evenly, consumed more upland forage before maximum riparian utilization was reached, and gained more weight. The economic impacts of these outcomes were increased with expected annual net returns to the ranch for the project ranging between 4,500 and 11,000 depending on cattle prices and precipitation levels.
Spatial and temporal patterns of cattle feces deposition on rangeland
Authors: Tate K. W. , Atwill E. R. , McDougald N. K. ,   Society for Range Management
Published: March 2016

The objective of this study was to identify and model environmental and management factors associated with cattle feces deposition patterns across annual rangeland watersheds in the Sierra Nevada foothills. Daily cattle fecal load accumulation rates were calculated from seasonal fecal loads measured biannually on 40 m2 permanent transects distributed across a 150.5 ha pasture in Madera County, Calif. during the 4 year period from 1995 through 1998. Associations between daily fecal load per season, livestock management, and environmental factors measured for each transect were determined using a linear mixed effects model. Cattle feces distribution patterns were significantly associated with location of livestock attractants, slope percentage, slope aspect, hydrologic position, and season. Transects located in livestock concentration areas experienced a significantly higher daily fecal load compared to transects outside of these concentration areas (P < 0.001). Percent slope was negatively associated with daily fecal load, but this association had a significant interaction with slope aspect (P = 0.02). Daily fecal load was significantly lower during the wet season compared to the dry season (P = 0.002). Daily fecal loading rates across hydrologic positions were dependent upon season. Our results illustrate the opportunities to reduce the risk of water quality contamination by strategic placement of cattle attractants, and provide a means to predict cattle feces deposition based upon inherent watershed characteristics and management factors.
Effects of aeration on phenolic amine content of guajillo
Authors: Windels S. K. , Hewitt D. G. , Forbes T. D. A. ,   Society for Range Management
Published: March 2016

Aeration is a common range management technique used in southern Texas and northern Mexico to reduce shrub cover and increase biomass of more palatable forages. Guajillo (Acacia berlandieri Benth.) is an important forage plant for deer and domestic livestock throughout its range in northeastern Mexico and southern Texas. It responds to top removal, such as by aeration, by producing large numbers of juvenile sprouts which can have higher total leaf nitrogen content up to 6 months after treatment. However, the concentration of phenolic amines, potentially toxic secondary plant chemicals, may also increase. We compared concentrations of tyramine and N-methyl-phenethylamine (NMP), 2 prominent phenolic amines that can negatively affect reproduction in herbivores, between juvenile (regrowth) and mature stems of guajillo in areas that had been aerated and also between mature stems in aerated and control sites. Aeration increased NMP but not tyramine concentrations in mature stems. Juvenile stems had higher total nitrogen concentration than mature stems but also had higher amine concentrations until about 1 year after aeration. A greater percent of total nitrogen was incorporated into amines in juvenile stems (2.5-6.0%) than mature stems (1.8-4.2%). Amine concentrations peaked in summer and early autumn, a period when herbivores may rely heavily on browse because forbs are scarce. Our results suggest that while aeration may result in higher nitrogen concentrations in guajillo, increases in amines may limit benefits to herbivores.
Herbicide effects on vegetation spatial patterns in a mesquite savanna
Authors: Heaton C. B. , Wu X. B. , Ansley R. J. ,   Society for Range Management
Published: March 2016

Several studies have examined the impact of woody plant (i.e., brush) management efforts on mesquite (Prosopis glandulosa Torr.) cover and associated ecological impacts, but little research has been done on spatial attributes of vegetation following mesquite management treatments. This study examined the effects of above-ground mortality (triclopyr or 2,4,5-T) and whole-plant mortality (clopyralid or triclopyr+clopyralid) mesquite herbicide treatments on the canopy cover and spatial pattern of vegetation in a mesquite savanna and the associated ecological and management implications. A GIS and landscape analysis based on classified color-infrared aerial photos were used to quantify the spatial patterns of woody and non-woody vegetation. The results indicate long-term (> 20 year) persistence of disturbance effects on the amount and spatial pattern of woody vegetation. Significant differences in spatial pattern were found between the herbicide treatments and the non-treated plots, as well as between the above-ground mortality (AGM) and whole-plant mortality (WPM) herbicide treatments. The differential changes in the amount and spatial distribution of woody cover under different treatments resulted in substantially different spatial distributions of non-woody vegetation with respect to distance to nearest woody vegetation. These spatial variations may influence production and zonation of herbaceous vegetation due to modified shading and root competition from mesquite. Our results support observations of differential rates of mesquite seedling recruitment and establishment between treatment types. We conclude that consideration of spatial pattern should be an important component of future brush management plans.
Carbon isotope discrimination and yield in 14 cool-season grasses
Authors: Johnson D. A. , Asay K. H. , Jensen K. B. ,   Society for Range Management
Published: March 2016

Selection for carbon isotope discrimination (delta) has potential for improving water-use efficiency in cool-season grasses. An understanding of how delta is affected by differential water application and its association with dry mater yield may be helpful in identifying the best cool-season grass species for breeding and improvement, and may assist in designing selection and breeding procedures for improving cool-season grasses. We designed a study to evaluate the response of delta and dry matter yield to a gradient of water application in 14 cool-season, perennial grasses. The grasses were established in a rainout shelter facility equipped with a line-source irrigation system to study the: i) trends in dry matter yield across 6 water levels (WL-1 through 6, ranging from 981 to 64 mm water applied) and delta across 3 water levels (WL-1, 3, and 5), ii) grass x water level interactions for these traits, and iii) relationship between dry matter yield and delta in these grasses across a 2-year period. When averaged across years, the grasses differed significantly for delta at the highest (WL-1) and lowest (WL-5) water levels, but not at WL-3. Reductions in delta were strongly linear from WL-1 to WL-5, and although some inconsistencies were evident, the trend was similar for all grasses. Grasses differed significantly for dry matter yield at each of the water levels. Although the change in dry matter yield was mostly linear across water levels, the trend was not consistent among the grasses. In general, delta was not closely associated with dry matter yield; however, some exceptions with high dry matter yield and high delta were evident. This lack of close association between dry matter yield and delta in these 14 grasses suggests that breeding efforts to improve these grasses should involve simultaneous selection for dry matter yield and delta.
Empowering diversity: envisioning, designing, and developing range management science
Authors: Scarnecchia D. L. ,   Society for Range Management
Published: March 2016

The fragmented, weak identity of range science has been disadvantageous to the institutions and individuals involved with it. This paper addresses a complex, interrelated group of issues related to range science, the Journal of Range Management, and the Society for Range Management. Beginning with the long-standing conception of the art of range management, it presents a concept of range management science that has multiple implications for the Society for Range Management and its flagship publication, the Journal of Range Management. The paper presents a strategically designed identity for range management science as a synthetic science, i.e., a science of synthesis, and examines the elements of diversity, synthesis, and communication that are the essence of that identity. It encourages a diverse, inclusive, synergistic character for, and offers many suggestions related to the philosophy and conduct of, the science, the Journal, and the Society. The harmonious vision of range management science that it presents is designed to give the science a strong, coherent, marketable identity. The vision is dynamic in that it can readily accommodate evolving changes. That vision is designed to make the diversity of the science and the Society work for us, rather than against us, by establishing a philosophical environment where the kind of scientific, institutional, informational, and professional synergies we need can flourish.
Brassica elongata ssp. integrifolia seed germination
Authors: Young J. A. , Clements C. D. , Wilson R. ,   Society for Range Management
Published: March 2016

Repeatedly during the late 19th and early 20th century, exotic weeds were introduced to the sagebrush (Artemisia)/bunchgrass rangelands of the Great Basin. Once established these weeds became invasive, spreading without the conscious efforts of humans. Brassica elongata ssp. integrifolia (Boiss.) Breistr. offers evidence this process of introduction still continues. Brassica elongata ssp. integrifolia is native to southeastern Europe and Asia. It was first collected in North America near Portland, Ore. in 1911. This initial infestation apparently did not persist. The next collection was near Eureka, Nev. in 1968. Currently, Brassica elongata ssp. integrifolia has spread about 200 km east and west along U S Highway 50 and 100 km north and south of the highway along secondary roads. As a first step in understanding the seed and seedbed ecology of this new invasive weed we investigated the germination of seeds at a wide range of constant and alternating temperatures. This plant produces abundant seeds that germinate over a wide range of constant and alternating temperatures. Maximum germination ranged from 84 to 94% depending on the year of seed production. Germination was extremely limited at very cold seedbed temperatures and low at the cold category of seedbed temperatures. Germination at these temperature is a competitive advantage for other exotic species on Great Basin rangelands.
Vegetation and deer response to mechanical shrub clearing and burning
Authors: Rogers James O. , Fulbright Timothy E. , Ruthven Donald C. ,   Society for Range Management
Published: March 2016

Prescribed burning is a recommended maintenance treatment following mechanical treatments of south Texas brushlands, but it is unknown whether it is preferable to additional mechanical treatments to improve habitat for white-tailed deer (Odocoileus virginianus Raf.). We tested the hypotheses that prescribed burning of aerated (top-growth removal of woody plants) plots during late summer would decrease protein-precipitating tannins in browse, increase forb biomass, and increase deer utilization compared to a second aeration. Ten patches of brush, ranging in size from 2.8-8.1 ha, were aerated during spring 1999. In late summer 2000, maintenance treatments were applied; 5 patches were burned and 5 were aerated a second time. Standing crop, nutritional quality, and tannin concentrations (browse only) of deer forages were estimated. Deer tracks crossing bulldozed lanes surrounding each patch were counted to estimate deer use. Standing crop of browse, forbs, grass, succulents, protein-precipitating tannins in browse, and track density did not differ between treatments. Based on deer use and forage biomass response, burning and a second aeration 16-17 months following an initial aeration appear to have similar effects on habitat characteristics and use of cleared patches by white-tailed deer. Because of lower cost, we recommended prescribed burning as a maintenance treatment of aerated shrublands.
Management optimization of dual-purpose barley (Hordeum spontaneum C. Koch) for forage and seed yield
Authors: El-Shatnawi Moh'd Khair J. , Al-Qurran Louy Z. , Ereifej Khalil I. ,   Society for Range Management
Published: March 2016

Dual-purpose barley (Hordeum spontaneum C. Koch.) is a winter annual native to Southern Mediterranean regions. It is used to establish permanent pasture because it has a brittle rachis. Crude protein, crude fiber contents, and responses of dual-purpose barley to time of defoliation were investigated in the northern mountains of Jordan. Field trials were conducted in the 1999-2000 and 2000-2001 growing seasons in Samta (32 degrees 23′N, 35 degrees50′E) at an elevation of 1043 m. The highest protein contents (P ≤ 0.05) of 25% were recorded in February 2001. Protein content declined gradually and reached the lowest values (2.5%) at maturity. Clipping produced shorter plants, but did not impact tillering. Clipping individual plants on 28 February (14.3 and 10.2 g plant-1, respectively in 2000 and 2001) and 15 March (10.3 and 9.2 g plant-1, respectively in 2000 and 2001) did not reduce the plant shoot weight. Forage production from plants clipped on 28 February (2902 and 1274 kg ha-1, respective years), 15 March (1793 and 1394 kg ha-1, respectively in 2000 and 2001) and 15 April (1554 and 994 kg h-1, respectively in 2000 and 2001) were similar to forage production from unclipped plants. Clipping on 15 April inhibited seed production. Defoliation during early growth stages optimized seed yield and forage quantity and quality.
Can spring cattle grazing among young bitterbrush stimulate shrub growth?
Authors: Ganskopp Dave , Svejcar Tony , Taylor Fred ,   Society for Range Management
Published: March 2016

Due to its palatability and forage quality, antelope bitterbrush (Purshia tridentata Pursh DC) is a desirable shrub across western US rangelands. Because little information is available regarding grazing management of young bitterbrush, a study was undertaken to explore stocking pressure thresholds and quantify effects of light and heavy spring cattle grazing on shrub growth. Rates of browsing and trampling and forage availability were monitored over 3 years in southeast Oregon. Across years, 29% of bitterbrush endured trampling in light-grazing treatments, and 55% experienced trampling under heavy grazing. Linear models relating time and cattle density successfully explained (r2 = 0.84-0.86) probabilities of bitterbrush being trampled. Forage utilization averaged 32% and 59% in lightly and heavily grazed units, and 14 and 62% of bitterbrush were browsed in lightly and heavily-grazed pastures, respectively. Cattle began browsing when herbaceous standing crop declined to 100-150 kg ha-1. Browsing in heavily-grazed pastures reduced diameters of bitterbrush by 4.5 to 9.5 cm in 1998 and 1999, but shrub height was unaffected. Lightly-grazed stands exhibited a 50% greater increase in bitterbrush diameter, 30% greater height increment, and 8% longer twigs than shrubs in ungrazed pastures. At the end of the 1997 and 1998 growing seasons, bitterbrush in heavily-grazed pastures were 11 cm greater in diameter than ungrazed controls and equal to shrubs in lightly-grazed pastures. To stimulate bitterbrush growth, young stands can be lightly-grazed (30 to 40% utilization of herbaceous forage) by cattle when bitterbrush is flowering and accompanying grasses are in vegetative to late-boot stages of phenology.
Stocking rate, precipitation, and herbage production on sand sagebrush-grassland
Authors: Gillen Robert L. , Sims Phillip L. ,   Society for Range Management
Published: March 2016

Knowledge of the relationship between stocking rate or grazing intensity and plant production is fundamental to the sustainable management of rangelands. The general management paradigm is that plant production declines as stocking rate increases. Our objective was to determine the impact of stocking rate on herbaceous production of a sand sagebrush (Artemisia filifolia Torr.)-grassland. Stocking rates averaging 43, 57, and 85 animal-unit-days ha-1 (AUD ha-1) for year-round grazing were applied from 1941 to 1961. Herbaceous plant production was determined by sampling standing crop in temporary exclosures at the end of the growing season from 1958 to 1961, the last 4 years of the grazing study. Total herbaceous production averaged over stocking rates and years was 1,490 kg ha-1. Grasses contributed 89% of the total while forbs contributed 11%. Total production averaged 1,540, 1,470, and 1,450 kg ha-1 for stocking rates of 43, 57, and 85 AUD ha-1 y-1, respectively. There were no differences among stocking rates for total production or for the production of any individual grass species (P > 0.05). Forb production was also not affected by stocking rate, averaging 200, 140, and 120 kg ha-1 for stocking rates of 43, 57, and 85 AUD ha-1 y-1 (P > 0.05). Differences in production among years were much greater than differences among stocking rates for all vegetation components. Little bluestem [Schizachyrium scoparium (Michx.) Nash] and sand lovegrass [Eragrostis trichodes (Nutt.) Wood] showed the greatest responses to favorable precipitation. Herbaceous production of this sand sagebrush-grassland was little affected by 20 years of differential stocking rates.
Macronutrients in soil and bromegrass after long-term N fertilization
Authors: Harapiak J. T. , Malhi S. S. , Gill K. S. ,   Society for Range Management
Published: March 2016

Information on the long-term impact of repeated annual fertilizer applications of different nitrogen (N) sources on soil and plants is needed to develop sustainable grassland production systems. The concentration of macronutrients in the 0-5, 5-10, 10-15, 15-30, 30-60, 60-90 and 90-120 cm layers in a thin Black Chernozemic (Typic Boroll) soil and in bromegrass (Bromus inermis Leyss.) hay were compared after 15 annual applications of 168 and 336 kg N ha-1 as ammonium nitrate, urea, calcium nitrate, and ammonium sulphate, and a zero-N check. The concentration of NO3-N was increased by ammonium nitrate and ammonium sulphate at both N rates in most soil layers, by calcium nitrate at both N rates and by urea at 336 kg N ha-1 in the 15-60 cm soil. The accumulation of NO3-N increased with soil depth down to 60 cm, except for urea and ammonium sulphate at 168 kg N ha-1, and then it declined in deeper soil layers. The concentration of NH4-N was increased with fertilizer applications in some of the surface soil layers. The concentration of P was increased in the top 15 cm soil by ammonium nitrate and ammonium sulphate. The concentrations of Ca, Mg and K in the surface soil declined with most of the N fertilizer treatments while some treatments increased the Ca and Mg concentrations in the deeper soil layers. Increasing the N rate from 168 to 336 kg N ha-1 usually accentuated the above stated N effects on the concentration of macronutrients in the soil. The nitrate-based fertilizers caused more accumulation of NO3-N in some soil layers than the ammonium-based fertilizers. The relative increase in the concentration of NH4-N and P and the decline in the concentration of Ca, Mg and K in the soil by N addition was usually associated with the concomitant lowering of soil pH by N fertilization. In bromegrass hay, the total N concentration was increased by N fertilization but the concentration of other elements, except K, usually declined because of the dilution effect of the extra hay yield associated with N addition. Increasing the N rate from 168 to 336 kg N ha-1 further elevated the total N concentration but had no effect on the concentration of the other elements. Total N concentration in the hay tended to be greater with ammonium sulphate and ammonium nitrate than with the other 2 fertilizers. The concentration of total S was greater with ammonium sulphate than the other N fertilizers, and the concentration of P, Ca, Mg and K was not affected by the N fertilizer type. Fertilizer-induced high levels of NO3-N, NH4-N and P in soil may present potential for environmental pollution at these high N rates.
Influence of auxin and sulfonylurea herbicides on seeded native communities
Authors: Lair Kenneth , Redente Edward F. ,   Society for Range Management
Published: March 2016

Sulfonylurea herbicides were used extensively for weed control on Conservation Reserve Program (CRP) seedings, constituting over 98% of the residual herbicides applied from 1986-1990 in southeastern Colorado. Differences in species establishment were observed in CRP fields treated with sulfonylurea herbicides, suggesting that soils and climatic variation alone did not fully account for this establishment pattern. Impacts of 2 commonly used sulfonylurea herbicides and 2 auxin herbicides on establishment, inter-specific seedling competition and physiological response under CRP field conditions were evaluated. Seeded species were blue grama [Bouteloua gracilis (Willd). Ex Kunth) Lag. ex Griffiths], sideoats grama [Bouteloua curtipendula (Michx.) Torr.], western wheatgrass [Pascopyrum smith; (Rydb.) A. Love], switchgrass [Panicum virgatum L.], and sand dropseed [Sporobolus cryptandrus (Torr.) Gray]. Sulfonylurea herbicide application increased sideoats grama cover and live standing crop as much as 43% over auxin herbicide and mowing treatments, whereas switchgrass and western wheatgrass were reduced up to 71% by sulfonylurea treatment. Switchgrass cover was reduced by application of either sulfonylurea or auxin herbicides. Blue grama and sand dropseed were least affected by herbicide treatment. Auxin herbicide treatment resulted in 70% increases in plant diversity for seeded species and total plant community over sulfonylurea treatment, primarily attributable to increased frequency of annual forbs. Seral stage was more advanced under sulfonylurea treatment, however, because of increased frequency, cover and live standing crop of perennial forbs, grasses, and half-shrubs.
Mourning dove densities on Chihuahuan Desert rangelands
Authors: Joseph Jamus , Holechek Jerry L. , Valdez Raul ,   Society for Range Management
Published: March 2016

Mourning dove (Zenaida macroura L.) densities were determined using strip census techniques over a 2-year period (spring 1996 to winter 1998) on pastures in early-, mid-, and late-seral ecological condition. This study was conducted on the Chihuahuan Desert Rangeland Research Center and adjacent Bureau of Land Management rangelands in south-central New Mexico on 6 adjoining pastures that were similar in terrain and shape. Mourning dove densities pooled across sampling periods (8) were different (P < 0.10) on pastures in mid- and early-seral condition. They averaged 10.3, 33.9, and 7.2 birds km-2 on pastures in late-, mid- and early-seral condition, respectively. Leatherleaf croton (Croton pottsii Lam.), the primary mourning dove food on all study pastures, was more abundant (P 0.10) on late- and mid-seral pastures than on early-seral pastures. Therefore, heavy livestock grazing may adversely affect mourning dove populations in the Chihuahuan Desert by depleting leatherleaf croton. Autumn perennial grass cover and standing biomass differed (P < 0.10) among seral stages. More optimal interspersion of bare ground and perennial grasses may further explain why mid-seral rangelands tend to favor mourning doves. Our study shows mourning doves in the Chihuahuan Desert prefer moderately grazed, mid-seral rangelands over heavily grazed, early-seral rangelands.
Landowner willingness to participate in a Texas brush reduction program
Authors: Kreuter Urs P. , Tays Mark R. , Conner J. Richard ,   Society for Range Management
Published: March 2016

Because most of Texas consists of privately owned land and the amount of brush cover on rangelands may affect off-site water yields, there has been increasing interest in publicly funded brush clearing programs aimed at increasing water yield. The Pedernales River was selected as 1 of 8 watersheds to determine the feasibility of implementing such a program. A survey questionnaire was mailed to 720 landowners in Blanco and Gillespie County (containing most of the Pedernales watershed) in June 2000 to identify factors that influence their interest in participating in a brush reduction program. The sample consisted of equal numbers of landowners with 4-20, 21-202, and > 202 ha of land. Fifty eight percent of the survey participants responded, 82% of whom answered questions about their willingness to enroll at least part of their land in a brush reduction program. Property size and income from wildlife were found to be significant positive determinants and level of satisfaction with brush a significant negative determinant of respondents' willingness to enroll. To optimize public investments, it may be preferable to maximize the area enrolled in a brush removal program by targeting larger landowners who appear to be willing to enroll larger portions of their land without requiring compensation that exceeds their net cost of enrollment. Because land in the Edwards Plateau is being subdivided and purchased by people who do not depend on land-based income and who may be more tolerant of brush, public funds required to encourage landowner participation may increase over time.
Clinical signs in cattle grazing high molybdenum forage
Authors: Majak Walter , Steinke Daniel , McGillivray Jason ,   Society for Range Management
Published: March 2016

Revegetation and sustainable cattle grazing are major objectives in the reclamation of mine tailings at the Highland Valley Copper mine in British Columbia, Canada. A total of 84 cow-calf pairs grazed forage extremely high in molybdenum (Mo) for 11 weeks in the summer and fall for 3 consecutive years (1999-2001). The average stocking rate was 0.63 ha AUM-1. The animals' diet consisted primarily of alfalfa (Medicago sativa L.) and orchardgrass (Dactylis glomerata L.) containing 100-400 ppm Mo. Both cows and calves showed adequate daily gains of 0.78 kg head-1 day-1 and 1.33 kg head-1 day-1, respectively. Uptake of Mo was demonstrated by elevated levels of Mo in rumen contents and feces. Clinical signs of Mo toxicity were observed in less than half of the cows and in only a few calves. Clinical signs included a stiff shuffling gait, watery diarrhea, and a rough hair coat. Lameness, the primary sign, was resolved in all animals by the end of each trial. Diarrhea was also resolved by the end of the trial and hair coats returned to normal by the following spring. The onset and severity of the affliction appeared to be related to prevailing moisture conditions, which may have affected Mo availability in forage. Some affected animals were treated with Cu injections to no avail. Liver biopsies and serum samples showed marginal to adequate copper (Cu) levels but potentially toxic levels of Mo. In the third year of the trial, Cu-containing boluses were employed but they did not prevent the onset of clinical signs.
Fertilization with nitrogen and potassium on pastures in temperate areas
Authors: Mosquera-Losada María Rosa , González-Rodriguez Antonio , Rigueiro-Rodríguez Antonio ,   Society for Range Management
Published: March 2016

Fertilizer application enable producers to influence pasture production. The effect of N fertilization on grass production and leguminous plant content of pasture and strategic N application has received much attention. Changing agricultural policies suggest that chemical fertilizer inputs may be diminished and that alternative sources of nutrients are desired. The aim of this study was to evaluate the effect of N and K fertilization on production, botanical composition, and forage mineral composition to gain some insight into what influence changing fertilization practices would have on pasture productivity. Three K and 3 N application rates were applied in a factorial design on a white clover (Trifolium repens L.)—perennial ryegrass (Lolium perenne L.) sward. Potassium and nitrogen application increased herbage production and had differential influences on botanical composition. Nitrogen decreased clover content in the pasture, whereas K increased the proportion and production of white clover. The effects of K application appeared later in the experiment than those associated with N. We concluded that K is very important for development and maintenance of white clover in pasture, which increases herbage and protein production. Nitrogen was associated with lesser amounts of N, P, K, and Mg in pasture, because of lesser amounts of clover in the sward. Changing fertilization practices will have definite influences on sward composition and pasture productivity. Any interpretation of pasture mineral content should take botanical composition changes into account.
The influence of land use on desertification processes
Authors: Pando-Moreno Marisela , Jurado Enrique , Manzano Mario ,   Society for Range Management
Published: March 2016

Site degradation occurs mainly through deterioration of the soil's capacity to capture and store water, as well as the loss of organic matter or the accumulation of salts or other toxic substances in the soil. This degradation process, leading to the reduction of the biotic potential of the site, is known as desertification. In this study, changes in bulk density, organic matter, and electrical conductivity are used as indicators of desertification in northeast Mexico. The hypotheses put forward here are that degradation processes are affecting extensive areas of the region, and that the type of processes and their magnitude differ according to specific land uses. Thirty-one sites under different land use systems (agriculture, rangeland, induced grassland, and a protected site) were sampled for bulk density, organic matter, and salinity. Soil samples for bulk density estimation were collected in 1996, 1997, and 1999, while those for organic matter and salinity were taken in 1993, 1997, and 1999. Soil bulk density and organic matter showed significant changes across time in rangeland sites. None of the sites showed significant changes in salinity. Organic matter was similar in agriculture, rangeland, and grassland sites across dates. Soil bulk density was similar in grasslands and rangelands and lower in agriculture sites. Values of organic matter were lower and those of soil bulk density were higher when compared to a protected native vegetation site.
Revegetation of waste fly ash landfills in a semiarid environment
Authors: Pierzynski Gary M. , Heitman Joshua L. , Kulakow Peter A. ,   Society for Range Management
Published: March 2016

This study investigated vegetation strategies for a fly ash landfill in a semi-arid environment. Ten plant species adapted to the local climate were initially evaluated for their germination characteristics in various mixtures of Tivoli fine sand, fly ash, and cattle manure. Alkali sacaton (native, Sporobolus airoides (Torr.) Torr.), blue grama (native, Bouteloua gracilis (H.B.K.) Lag. Ex Griffiths), a forage sorghum (variety Canex, Sorghum bicolor (L.) Moench), sand bluestem (variety Woodward, Andropogon hallii Hack.), and sideoats grama variety El Reno, Bouteloua curtipendula (michx.) Torr.) were selected for further evaluation. Concurrently, mixtures were evaluated to determine the effects of the soil amendments on soil saturated paste electrical conductivity (EC) and pH. The addition of even 50 g kg-1 fly ash increased EC values above 4.0 dS m-1, indicating salt tolerant species may be needed. Six mixtures were selected for use in a greenhouse study and for further study of moisture retention characteristics. Using an X/Y format, where X is fly ash content and Y is manure content (g kg-1) and the balance of the mixture was Tivoli fine sand, those mixtures were 0/0, 200/0, 200/100, 200/200, 100/100, and 300/100. The addition of manure provided ample quantities of plant nutrients. Alkali sacaton was the only plant specie not adversely affected by the addition of fly ash. For biomass production, height, vigor and leaf tip burn, all remaining species had significantly better growth or ratings with 0/0 as compared to any other mixture. Soil moisture retention characteristics of the Tivoli fine sand can be significantly changed through amendment with fly ash or manure. Sixty cm of Tivoli sand was estimated to have the same available water holding capacity as 45 cm of 200/0, 39 cm of 200/100, 34 cm of 200/200, 47 cm of 100/100, and 33 cm of 300/100.