bluuebunny/crossref_metadata_2025 huggingface dataset:
Fire Rehabilitation Using Native and Introduced Species: A Landscape Trial
Authors: Thompson Tyler W. , Roundy Bruce A. , McArthur Durant E. ,   Society for Range Management
Published: June 2016

Following the 1999 Railroad Fire in Tintic Valley, Utah, we initiated a large-scale fire rehabilitation study comparing a predominately introduced species seed mix used by the US Department of Interior-Bureau of Land Management (BLM), a mix of native and introduced species provided by the US Department of Agriculture-Agricultural Research Service (ARS), and 2 native seed mixes (high and low diversity). Mixes were seeded with a rangeland drill on the big sagebrush (Artemisia tridentata var. wyomingensis [Beetle A. Young] Welsh) study area whereas the pinyon-juniper (Pinus edulis Engelm.-Juniperus osteosperma [Torr.] Little) woodland study area was aerially seeded followed by 1-way chaining. On drill-seeded plots and by the third year after seeding the native high-diversity mix (16.4 kg pure live seed [PLS] ha-1) had the highest seeded species cover (11.5%) and density (14 plants m-2). Both the BLM (9.3 kg PLS ha-1) and ARS (9.1 kg PLS ha-1) seed mixes had higher seeded species cover (BLM = 8.5%, ARS = 8.2%) and density (BLM = 8.4 and ARS = 7.2 plants m-2) than plots seeded to the low-diversity native mix (8 kg PLS ha-1, cover = 3.8%, density = 3.6 plants m-2). Indian ricegrass (Achnatherum hymenoides [Roemer and J. A. Schultes] Barkworth ‘Nezpar’) in the native high-diversity mix was especially successful on the sandy soils of the drill site, whereas seeds of other species may have been buried too deep for optimum emergence. Aerially-seeded and chained plots had similar and successful seeded species frequency, cover, and density (third-year average = 10.6% cover, 17.2 plants m-2) among all species mixes. All seeded plots had lower cover of annual species than unseeded plots, indicating that revegetation is necessary to reduce weed invasion following catastrophic wildfire in big sagebrush communities lacking residual perennial understory vegetation.
Stockpiled Forage Kochia to Maintain Beef Cows During Winter
Authors: Waldron Blair L. , ZoBell Dale R. , Olson Kenneth C. ,   Society for Range Management
Published: June 2016

Extending grazing into the winter, as opposed to feeding of harvested forages, can increase the sustainability of ranching in the western US. This study was conducted to determine the economic value of grazing stockpiled forage kochia (Kochia prostrata [L.] Scrad.) and crested wheatgrass (Agropyron desertorum [Fisch. Ex Link] Schultes) during the fall and winter. Changes in cow body weight, body condition score, and ultrasound backfat were compared for late-gestation cows grazing forage kochia- crested wheatgrass pastures vs. those fed alfalfa (Medicago sativa L.) hay in drylot. The study was conducted from early November to late January for 2 consecutive years near Promontory, Utah. Forage availability and nutritional quality were monitored throughout the experiment. Cows grazing stockpiled forages did not receive any protein or energy supplements. Forage kochia comprised approximately 70% of available forage, with November crude protein content of 116 and 76 g kg-1 in years 1 and 2, respectively. Nutritional quality declined throughout the season, presumably mostly because of removal of higher-quality forage by preferential grazing as opposed to weathering. Averaged over years, cows grazing forage kochia-grass gained body weight (19 kg), increased in body condition (0.3 points), and maintained backfat thickness, finishing well within the range considered optimum for onset of calving and return to estrus. Pasture- vs. drylot-fed cows did not differ with regard to changes in body weight or body condition score. Both treatments increased backfat in year 1, when initial backfat was less than 0.5 cm, but both treatments resulted in loss of backfat in year 2, when initial backfat was greater than 1.0 cm. Grazing was more economical, costing 0.24 cow-1 d-1 less than feeding alfalfa hay in drylot. Forage kochia can be used on western rangelands to extend grazing into the fall and winter, thereby improving the profitability of beef production.
Effect of Fire on Microarthropods in New Zealand Indigenous Grassland
Authors: Barratt Barbara L. P. , Tozer Peter A. , Wiedemer Robin L. ,   Society for Range Management
Published: June 2016

Indigenous tussock grassland in New Zealand has a history of extensive pastoralism, and burning has been used to remove litter to improve establishment of aerially oversown pasture species and to promote palatable tussock growth for livestock. In recent years, considerable areas of tussock grassland have been retired from grazing and formally protected. Conservation land managers, as well as farmers, require information on the impacts of both managed burns carried out in spring and accidental fires that usually occur in warmer, drier conditions in summer. This study investigated the impact of spring and summer tussock grassland burning on the predominant soil microarthropods, Collembola and Acari, at 2 sites in Otago, in the South Island of New Zealand. Quantitative sampling was carried out before and for up to 26 months after burning replicated 1-ha plots. Total density of microarthropods in unburnt plots covered a similar range at both sites with an average over 3 years of about 18 000- 20 000 m2 at each site. Both sites shared a dominance of Mesostigmata and Oribatida (Acari) and Isotomidae (Collembola). Burning in spring reduced densities of Oribatida after treatment at both sites for the duration of the study. However, after initial postburn reductions in density, populations of Isotomidae and Poduroidea (Collembola) recovered in the second year after burning. Prostigmata (Acari) appeared to be unaffected by fire. The effects of spring and summer grassland fires on microarthropod densities were rarely different. It was concluded that longer-term sampling would be required to observe the full recovery period for microarthropod populations after fire but that results from this study indicate rapid recovery of some microfaunal populations after fire, which is not strongly influenced by seasonal effects.
Consequences of Ignoring Geologic Variation in Evaluating Grazing Impacts
Authors: Long Jonathan W. , Medina Alvin L. ,   Society for Range Management
Published: June 2016

The geologic diversity of landforms in the Southwest complicates efforts to evaluate impacts of land uses such as livestock grazing. We examined a research study that evaluated relationships between trout biomass and stream habitat in the White Mountains of east-central Arizona. That study interpreted results of stepwise regressions and a nonparametric test of ‘‘grazed and ungrazed meadow reaches’’ as evidence that livestock grazing was the most important factor to consider in the recovery of the Apache trout (Oncorhynchus apache Miller). That study had assumed that geologic variation was insignificant in the study area. However, lithologic and topographic differences between the felsic slopes of Mount Baldy and adjacent mafic plateaus influence many attributes of trout habitat. We tested the robustness of the earlier study by using its dataset and its method of stepwise regression, but with the addition of a variable representing geologic variation. The results suggested that geology was a highly significant predictor of trout biomass (P < 0.0001), whereas bank damage by ungulates was not a useful predictor of residual variation in trout biomass after accounting for geology (r2 = 0.015, P = 0.290). However, the associations between natural variation and land use impacts in this spatial dataset confound attempts to make inferences concerning effects of livestock grazing upon trout. Despite fundamental problems in the analysis, the results of the earlier study were repeatedly cited in scientific literature and debates about grazing management. To fairly decipher relationships between ecological production and livestock grazing in diverse landscapes requires temporal studies with reliable methodologies and proper controls for landscape variation. Ignoring geologic variation has the potential to mislead conservation policies by inappropriately implicating land use, by undervaluing inherently favorable habitats, and by inflating expectations for inherently less favorable habitats.
Spatial Variation in Remnant Grasses After a Grassland-to-Shrubland State Change: Implications for Restoration
Authors: Peters Debra P. C. , Mariotto Isabella , Havstad Kris M. ,   Society for Range Management
Published: June 2016

Around the world rangelands that have been degraded, such as historical desert grasslands now dominated by woody shrubs, are resistant to restoration efforts. The goal of this descriptive research was to examine the potential for black grama (Bouteloua eriopoda [Torr.] Torr.) recovery by remnant plants in a degraded area as a function of plant location across a landscape. Our objectives were 1) to document the historical dominant vegetation as a perennial grassland and determine broad-scale changes in dominance through time and 2) to examine fine-scale patterns of black grama presence and basal area with respect to microenvironmental conditions that indicate the landscape positions favorable for restoration. Historical vegetation maps starting in 1858, a field survey in 2002-2003 of the location of all individual black grama plants in a 29-ha area, and spatial data layers in a geographic information system were used to address these objectives. Upland grasses, including black grama, dominated the study site in 1858, although tarbush (Flourensia cernua DC.) was the dominant species by 1915, and creosotebush (Larrea tridentata [DC.] Cov.) is the current dominant. A total of 3 334 black grama plants were found for an average density of 0.01 plants m-2. High spatial variation was found in the occurrence and basal area of black grama plants that was related to water availability rather than livestock grazing: most plants were found in or adjacent to an arroyo (67%), at a northern aspect (47%), and outside experimental exclosures established in 1930 (43%). Largest average basal areas were found in the livestock exclosure, and in general, average basal area was not related with aspect or canopy microsite. These remnant plants can be used as propagule sources in restoration efforts, and information on microsite conditions for black grama survival can be used to improve restoration potential for similar sites.
Near-Ground Remote Sensing of Green Area Index on the Shortgrass Prairie
Authors: Przeszlowska Agnieszka , Trlica Milton J. , Weltz Mark A. ,   Society for Range Management
Published: June 2016

Drought is an inherent trait of most rangelands and sound management necessitates managers address two fundamental questions when facing a drought situation. The first question is, ‘‘what is the probability that a useful amount of precipitation will be received over the period of concern?’’ and the second question is, ‘‘if it does rain, what will the impact be in terms of quantity and quality of herbage produced?’’ The objective of this study was to address the second question. Our hypothesis was that herbage growth response to above normal summer precipitation (i.e., 23 in July and August) would be limited in the northern Great Plains because of a general absence of productive warm-season species. Study plots were twelve 5 X 10-m non-weighing lysimeters. Treatments were: 1) simulated (i.e., rainout shelter imposed), severe spring drought (i.e., 1 May - 1 July) followed by ambient precipitation thereafter; 2) simulated, severe spring drought followed by ambient precipitation thereafter plus summer irrigation (i.e., July and August); 3) ambient precipitation only; and 4) ambient precipitation plus summer irrigation. Results indicated substantial herbage production can be expected in this region during summer when precipitation is well above average because of the positive growth response of blue grama (Bouteloua gracilis [H.B.K.] Lag. ex Griffiths), the dominant warm-season grass growing in this region. However, results also showed that level of production in the study situation (i.e., spring drought, wet summer) was only about 50% of that attained in a normal (i.e., wet spring/dry summer) year. Moreover, long-term weather data shows the probability of receiving 23 normal precipitation in both July and August (i.e., our irrigation treatments) is < 1%. Thus, although these rangelands possess the capacity to respond favorably to summer precipitation, the low probability of receiving substantial levels of summer precipitation ensures levels of ecological and economic risk remain high.
Spatio-Temporal Constraints on Moose Habitat and Carrying Capacity in Coastal Alaska: Vegetation Succession and Climate
Authors: Stephenson Thomas R. , Ballenberghe Victor Van , Peek James M. ,   Society for Range Management
Published: June 2016

We used a geographic information system and a Markov chain analysis to model vegetation succession on the Copper River Delta, Alaska, relative to moose (Alces alces) habitat availability and nutritional carrying capacity. Between 1959 and 1986 vegetation predominantly shifted from pioneer to later successional communities as a result of glacial retreat and earthquake uplift. Hypothesized vectors of vegetation composition in future decades indicate a trend toward an increase in late-successional communities. A decline in glacier-related disturbance has reduced the level of retrogression that maintains early successional communities in the outwash plain. In addition, landscape heterogeneity increased significantly between 1959 and 1986, particularly in the uplifted marsh. Winter severity was highly variable among years and was correlated with a shift in the location of moose wintering areas. As winter severity increased, there was increased use of the glacial outwash plain landform and its associated plant communities. Successional modeling suggests a decline in the availability of vegetation types impor- tant to moose during severe winters with deep snow. Low willow (Salix spp.) communities are expanding in the uplifted marsh, a landform used primarily during summer and mild winters. However, tall willow communities that provide winter forage are declining and are being replaced by Sitka spruce (Picea sitchensis [Bong] Carr) forest in the glacial outwash plain. Consequently, nutritional carrying capacity of moose on the outwash plain during winter will decline by 42% during 1959-2013.
Use of Fluorometry to Differentiate Among Clipped Species in the Genera Astragalus, Oxytropis, and Pleuraphis
Authors: Anderson Dean M. , Rayson Gary D. , Obeidat Safwan M. ,   Society for Range Management
Published: June 2016

A rapid and reproducible method to determine botanical composition of forage is an ecological and economic goal for range animal ecologists. Multidimensional fluorometry previously demonstrated the possibility of a unique optical approach for accurately determining species composition of clipped and digested plant materials. Fluorometry may be used to detect toxic plants in standing crop as well as diets by using electronic transitions in chemical structures at wavelengths between 370 and 580 nm. Grass hay (genus Pleuraphis) and 6 clipped forbs (4 species of Astragalus and 2 species of Oxytropis) were examined. The resulting spectral signatures were evaluated for differences in the blue and green regions of the visible spectrum using Principal Component Analysis (PCA). This represents the first published data using chemometrics to differentiate among fluorophores from these plant extracts. It was possible to distinguish between the grass and forbs and among forbs. Further research will be required to evaluate these same plant species in mixed diets and fecal samples.
Establishing Vegetation on Migrating Inland Sand Dunes in Texas
Authors: Fulbright Timothy E. , Ortega-Santos Alfonso J. , Lozano-Cavazos Alejandro ,   Society for Range Management
Published: June 2016

Migration of sand dunes damages range improvements in the Texas Coastal Sand Plain. We determined effects of mulching with native prairie hay and an open weave geotextile fabric, seeding, fertilization, and transplanting on plant species canopy cover on inland sand dunes. We compared applying native hay vs. a synthetic geotextile material to inhibit wind erosion, seeding ‘Alamo’ switchgrass (Panicum virgatum L.), ‘Mason’ sandhill lovegrass (Eragrostis trichodes [Nutt.] Wood), and partridge pea (Chamaecrista fasciculata [Michx.] Greene) vs. no seeding, and fertilization with 468 kg ha-1 of 45:45:90 (N:P:K) vs. no fertilization. The same treatments were compared in a second experiment except that switchgrass, sandhill lovegrass, vetiver (Vetiveria zizanoides [L.] Nash ex Small), and giant reed (Arundo donax L.) were transplanted rather than seeded. Treatments were applied during March and April 1994 and canopy cover of vegetation in each experimental unit was estimated in October 1994, 1995, and 2004. Livestock were excluded from the study sites. The geotextile fabric degraded within 4 months and was replaced with coastal Bermuda (Cynodon dactylon [L.] Pers.) hay. Fertilization plus native hay mulch resulted in greater (P < 0.05) canopy cover of purple sandgrass (Triplasis purpurea [Walt.] Chapm.), sandbur (Cenchrus incertus M. A. Curtis and C. echinatus L.), and snakecotton (Froelichia spp.) than other treatments in 1994. In 1994 and 1995, canopy cover of switchgrass and sandhill lovegrass was greater (P < 0.05) with a combination of geotextile fabric and commercial hay, seeding, and fertilization than in other treatments. Vegetation composition and canopy cover were similar (P > 0.05) across treatments in 2004 in both experiments. Fertilization, seeding, and transplanting appear unnecessary to establish vegetation on dunes protected from livestock grazing when mulch is applied to inhibit sand movement.
The Use of Landsat 7 Enhanced Thematic Mapper Plus for Mapping Leafy Spurge
Authors: Mlandinich Carol S. , Bustos Monica Ruiz , Stitt Susan ,   Society for Range Management
Published: June 2016

Euphorbia esula L. (leafy spurge) is an invasive weed that is a major problem in much of the Upper Great Plains region, including parts of Montana, South Dakota, North Dakota, Nebraska, and Wyoming. Infestations in North Dakota alone have had a serious economic impact, estimated at 87 million annually in 1991, to the state’s wildlife, tourism, and agricultural economy. Leafy spurge degrades prairie and badland ecosystems by displacing native grasses and forbs. It is a major threat to protected ecosystems in many national parks, national wild lands, and state recreational areas in the region. This study explores the use of Landsat 7 Enhanced Thematic Mapper Plus (Landsat) imagery and derived products as a management tool for mapping leafy spurge in Theodore Roosevelt National Park, in southwestern North Dakota. An unsupervised clustering approach was used to map leafy spurge classes and resulted in overall classification accuracies of approximately 63%. The uses of Landsat imagery did not provide the accuracy required for detailed mapping of small patches of the weed. However, it demonstrated the potential for mapping broad-scale (regional) leafy spurge occurrence. This paper offers recommendations on the suitability of Landsat imagery as a tool for use by resource managers to map and monitor leafy spurge populations over large areas.
Determining the Composition of Herbivore Diets in the Trans-Himalayan Rangelands: A Comparison of Field Methods
Authors: Shrestha Rinjan , Wegge Per ,   Society for Range Management
Published: June 2016

In late summer, in a semi-arid mountain range in Nepal, we compared 3 field methods for determining the botanical compositionof herbivore diets. Data were collected from the same animals belonging to 1 herd of domestic yak (Bos grunniens) and 2 herds of mixed smallstock, consisting of domestic goats (Capra hircus) and sheep (Ovis aries). Bite count, feeding site examination,and microhistological analysis of feces gave different estimates of forage categories and plant species in both animal groups. Because yaks grazed in other vegetation communities when not observed for bite-counts and feeding signs, the results from the latter methods could not be compared directly with that from fecal analysis. In smallstock, feeding site examination gave higher estimates of graminoids and lower estimates of shrubs than the other 2 methods, probably because all feeding signs on shrubs were not detected. Bite-counts and fecal analysis gave comparable results, except that forbs were underestimated by fecal analysis, presumably due to their more complete digestion. Owing to the difficulty in collecting samples that are representative of the entire grazing period and the problem of recording feeding signs correctly, both feeding site examination and bite-counts are unsuitable methods for studying the food habits of free ranging domestic and wild herbivores. Microhistological analysis of feces appears to be the most appropriate method, but correction factors are needed to adjust for differential digestion. The systematic use of photomicrographs improves the speed and accuracy of the fecal analysis.
Classification of Leafy Spurge With Earth Observing-1 Advanced Land Imager
Authors: Stitt Susan , Root Ralph , Brown Karl ,   Society for Range Management
Published: June 2016

Leafy spurge (Euphorbia esula L.) is an invasive exotic plant that can completely displace native plant communities. Automated techniques for monitoring the location and extent of leafy spurge, especially if available on a seasonal basis, could add greatly to the effectiveness of control measures. As part of a larger study including multiple sensors, this study examines the utility of mapping the location and extent of leafy spurge in Theodore Roosevelt National Park using Earth Observing-1 satellite Advanced Land Imager (ALI) scanner data. An unsupervised classification methodology was used producing accuracies in the range of 59% to 66%. Existing field studies, with their associated limitations, were used for identifying class membership and accuracy assessment. This sensor could be useful for broad landscape scale mapping of leafy spurge, from which control measures could be based.
Soil Nitrogen Availability in Tallgrass Prairie Under the Fire-Grazing Interaction
Authors: Anderson R. H. , Fuhlendrof Samuel D. , Engle David M. ,   Society for Range Management
Published: June 2016

Fire and grazing are interactive disturbance processes that are important to the structure and function of grassland ecosystems. Studies of nitrogen (N) availability report different effects following grazing and fire. However, these studies have largely neglected the spatially controlled interaction between fire and grazing. The objective of our work was to evaluate an application of the fire-grazing interaction model on N availability in a tallgrass prairie. We compared patches within a shifting mosaic landscape where each patch varied in time since focal disturbance (fire and intense grazing disturbance). We also evaluated N availability on a burned and grazed landscape where fires and moderate grazing occurred annually and uniformly across the entire landscape. These treatments were both burned and grazed where the only difference was spatial and temporal variability in fire application and grazing disturbance. Samples were collected from upland sites in May of 2003 and 2004. Total soil inorganic N (NH4+/-N + NO3-N) and a growth chamber experiment with hard red winter wheat (Triticum aestivum L. cv. Jagger) were used to evaluate potential N availability. Our study produced patterns of N availability that are more similar to studies of grazing lawns where N availability is enhanced by focal grazing than from studies of fire without grazing. Overall,our study demonstrates that fire and grazing are interactive. Unburned patches have minimal grazing pressure and low N availability. Fire-grazing interaction may provide a management alternative that enables sustainable livestock production, through increased carrying capacity in focally disturbed patches, concomitant with biological diversity in tallgrass prairie.
Grasshopper Abundance in an Arizona Rangeland Undergoing Exurban Development
Authors: Bock Carl E. , Jones Zach F. , Bock Janes H. ,   Society for Range Management
Published: June 2016

Housing developments are replacing ranches in the southwestern United States, with potentially significant but little-studied ecological effects. We counted grasshoppers (Orthoptera: Acrididae) and measured vegetative cover for 2 years in a grassland and mesquite/oak savanna in southeastern Arizona, on 48 transects that were grazed by livestock, embedded in low-density housing developments, or both, or neither. Grasshopper species richness was unrelated to grazing or development, but grasshopper abundance was much higher on exurban transects where homeowners kept livestock than in the other areas. Forb canopy and basal area also were highest in grazed exurban areas, perhaps because exurban grazing was relatively patchy, frequently involved horses, and created disturbances more conducive to forb establishment than did relatively uniform grazing on nearby ranches. Abundance patterns of 3 grasshopper subfamilies were generally consistent with their known habitat preferences. Counts of grass-feeding Gomphocerinae were relatively high in ungrazed and unburned areas, and positively correlated with grass cover. Numbers of forb- and mixed-feeding Melanoplinae were positively correlated with forb cover across all transects, and melanoplines dominated counts on grazed exurban properties. Band-winged grasshoppers (Oedipodinae) prefer areas of sparse vegetation, and their numbers were negatively correlated with height of ground vegetation and positively associated with the presence of livestock, in both exurban and undeveloped landscapes. Overall, our results suggest that heterogeneous landscapes in exurban areas that included small livestock pastures had higher grasshopper densities than either ungrazed areas or large cattle ranches.
Improving Germination in Windmillgrass Ecotypes
Authors: Herrera-C F. , Ocumpaugh W. R. , Ortega-S J. A. ,   Society for Range Management
Published: June 2016

Hooded windmillgrass (Chloris cucullata Bisch.) and shortspike windmillgrass (C. subdolichostachya Muell.) are native perennial grasses with potential for planting on highly erodible sites and on sites where introduced species are not desired. However, in both species, seeds are dormant resulting in poor germination. The objectives of this study were to evaluate effects of lemma and palea removal and caryopsis scarification on seed germination of 8 outstanding ecotypes selected in previous studies for survival and growth characteristics. Seed treatments were 1) whole seed, 2) naked caryopsis, 3) scarified naked caryopsis (30 s), 4) scarified naked caryopsis (50 s), and 5) scarified naked caryopsis (60 s). Germination conditions were 12 h dark 208C and 12 h light 308C. Seed lot viability varied from 55% to 62% for shortspike windmillgrass ecotypes and from 71% to 78% for hooded windmillgrass ecotypes. Initial germination index (MIR10) of naked caryopsis for shortspike windmillgrass ecotypes ranged from 16.3 to 21.6, compared to range from 0.2 to 0.6 to whole seed; whereas hooded windmillgrass ecotypes MIR10 ranged from 30.6 to 33.0 to naked caryopsis, compared to range from 5.8 to 8.0 to whole seed. The greatest total germination (P < 0.05) was obtained with naked caryopsis for all ecotypes and the scarification treatments did not have a positive effect on this parameter. As scarification time increased the total germination decreased. Lemma and palea removal improved (P < 0.05) total germination for all studied ecotypes.
Soil Erosion Thresholds and Alternative States in Northeastern Patagonian Rangelands
Authors: Chartier Marcelo P. , Rostagno César M. ,   Society for Range Management
Published: June 2016

In semiarid rangelands, continuous grazing may decrease vegetation cover, accelerating soil erosion and eventually causing a transition to an alternative, degraded state. State-and-transition models invoke process-based explanations of alternative states, but there are few examples that use empirical data on key factors and processes. We used rainfall simulation to determine 1) the relationships between soil surface characteristics and interrill erosion in 3 spatially related plant communities: stable grass with scattered shrubs (GS), degraded grass with scattered shrubs (DGS), and degraded shrub steppes (DSS), and 2) the site conservation threshold (SCT) of this rangeland. We also analyzed the effect of past erosion on soil and vegetation characteristics. In the GS, sediment production and sediment concentration were significantly lower (P<0.05) than in the DGS and the DSS.The main soil protection factors in the GS and in the DGS were perennial grass and litter cover, while in the DSS, gravel cover became the main soil protection factor. The SCT, the point at which the rate of soil erosion increases markedly, corresponded to a plant-and-litter cover close to 90% and occurred within the DGS. Although this plant community may reverse back to the conserved GS, long-term accelerated erosion may result in enough soil loss to trigger irreversible changes and prompt the transition to the DSS. The threshold underlying this transition would be reached when the A horizon is severely reduced by erosion. Under these conditions, the soil hydrological properties are affected irreversibly, preventing perennial grass establishment. While the GS represents a resource conserving plant community, desirable for both forage production and soilprotection, the DSS represents a dysfunctional state with a minimum forage value. The DGS represents an unstable and transitional community that, without management intervention to halt soil erosion, will likely change into the DSS.
Long-Term Dynamics of Production, Respiration, and Net CO2 Exchange in Two Sagebrush-Steppe Ecosystems
Authors: Gilmanov Tagir G. , Svejcar Tony J. , Johnson Douglas A. ,   Society for Range Management
Published: June 2016

We present a synthesis of long-term measurements of CO2 exchange in 2 US Intermountain West sagebrush-steppe ecosystems. The locations near Burns, Oregon (1995-2001), and Dubois, Idaho (1996-2001), are part of the AgriFlux Network of the Agricultural Research Service, United States Department of Agriculture. Measurements of net ecosystem CO2 exchange (Fc) during the growing season were continuously recorded at flux towers using the Bowen ratio-energy balance technique. Data were partitioned into gross primary productivity (Pg) and ecosystem respiration (Re) using the light-response function method. Wintertime fluxes were measured during 1999/2000 and 2000/2001 and used to model fluxes in other winters. Comparison of daytime respiration derived from light-response analysis with nighttime tower measurements showed close correlation, with daytime respiration being on the average higher than nighttime respiration. Maxima of Pg and Re at Burns were both 20 g CO2 m2 d-1 in 1998. Maxima of Pg and Re at Dubois were 37 and 35 g CO2 m-2 d-1, respectively, in 1997. Mean annual gross primary production at Burns was 1 111 (range 475-1 715) g CO2 m-2 y-1 or about 30% lower than that at Dubois (1 602, range 963-2 162 g CO2 m-2 y-1). Across the years, both ecosystems were net sinks for atmospheric CO2 with a mean net ecosystem CO2 exchange of 82 g CO2 m-2 y-1 at Burns and 253 g CO-2 m-2 y-1 at Dubois, but on a yearly basis either site could be a C sink or source, mostly depending on precipitation timing and amount. Total annual precipitation is not a good predictor of carbon sequestration across sites. Our results suggest that Fc should be partitioned into Pg and Re components to allow prediction of seasonal and yearly dynamics of CO2 fluxes.
Effect of Types of Biosolids and Cattle Manure on Desert Grass Growth
Authors: Mata-González Richardo , Sosebee Ronald E. , Wan Changgui ,   Society for Range Management
Published: June 2016

We compared the effect of applying anaerobically produced biosolids, lime-stabilized biosolids, and cattle manure on the production of blue grama (Bouteloua gracilis [HBK] Lag. ex Steud.) and black grama (B. eriopoda [Torr.] Torr.) grown in pots with moderate soil water content. We also compared the physicochemical and bacteriological composition of these 3 amendments. All amendments produced similar increases in plant growth, despite their differences in plant nutrient concentrations, as a result of limitations in soil water. Heavy metal levels in biosolids were within the US Environmental Protection agency limits for Class A and Class B biosolids, but were higher than in manure. In contrast, pathogen levels were lower in biosolids than in manure. Application of biosolids and cattle manure increased the production of both grasses and may have equivalent effects under typical climatic and soil conditions of semiarid rangelands.
Property Rights Orientations and Rangeland Management Objectives: Texas, Utah, and Colorado
Authors: Kreuter Urs P. , Nair Malini V. , Jackson-Smith Douglas ,   Society for Range Management
Published: June 2016

In response to substantial economic and social dislocations in the United States, many rangeland owners are changing land use and management practices. Changes in land use can significantly affect the services rangeland ecosystems provide. Decisions associated with such changes are likely mediated by landowner views regarding individual rights, social responsibilities, and the future security of property rights. In this paper, we examine the extent to which landowners are likely to adopt, without public compensation, socially desirable land management objectives that enhance ecosystem services from rangelands. The study consisted of a mail survey of landowners with at least 40 ha: 500 in Texas, 500 in Utah, and 694 in Colorado. Adjusted responserates were 62% in Texas, 46% in Utah, and 51% in Colorado. Regression analyses showed that willingness to adopt socially desirable rangeland management objectives was positively correlated with the social responsibility dimension of respondents’ property rights orientations but negatively correlated with the rights erosion dimension. Our results also suggested that landowners in private land states, such as Texas, might be less willing than landowners in states with more public land to manage their land for the maintenance of ecosystem services without being compensated. Although the scope of our study was limited, the results suggest that agencies tasked with maintaining ecosystem services on private rangelands might more successfully achieve their mission by promoting social responsibility among landowners. Including community leaders with a highly developed sense of social responsibility in programs aimed at improving land stewardship and including peer-pressure incentives in such programs might enhance social responsibility perspectives among landowners. Such programs should also be adaptable at the state-level to account for differences in property-rights orientations relative to landowner dependence on private and public land.
Long-Term Water Balance in a Semiarid Shrubland
Authors: Wilcox Bradford P. , Downhower Steven L. , Teague W. Richard ,   Society for Range Management
Published: June 2016

Baseline information on the water balance is essential for adequately understanding ecohydrological relationships on rangelands. Unfortunately, such information is not always available, because insufficient data have been collected and/or the data do not represent relevant temporal or spatial scales. In particular, for many rangelands long-term records of runoff at the small catchment or larger scales are relatively rare. In this study, we used catchment-scale data, collected over nearly a decade, to estimate the long-term water balance for mesquite-juniper rangelands in the Rolling Plains of Texas. The data include precipitation, surface runoff, soil water, and vegetation cover; these were measured on 9 microcatchments, each about 1.4 ha in size. Soil water was determined by neutron-probe measurements to a depth of 120 cm. Surface runoff was, surprisingly, a very small component (<1%) of the water budget and occurred only during extraordinary precipitation events. Soil-water recharge resulted mainly from winter precipitation. Evapotranspiration, which took place during the entire year, ranged from less than 1 mm day-1 during the winter to almost 8 mm day-1 during the summer. This study is important because it clearly documents how water is allocated on these rangelands at spatial and temporal scales that are relevant to management. The results from this study, in conjunction with other work in the Rolling Plains, suggests that there is little potential for increasing water yield via brush control in these landscapes.
Book Review: Energy Development and Wildlife Conservation in Western
North America, David E. Naugle (Ed.)
Authors: Rostker Margaret ,   Society for Range
                        Management
Published: June 2016

Book Review: Energy Development and Wildlife Conservation in Western
North America, David E. Naugle (Ed.). Island Press, Washington, DC, USA
(2011).
Quantitative Untersuchung der Streubeiträge in Hochenergie-Röntgencomputertomografie
Authors: Stritt Carina , Schuetz Philipp , Plamondon Mathieu , Flisch Alexander , Hofmann Jürgen , Sennhauser Urs
Published: June 2016

Kurzfassung

Computertomografie (CT) ist eine bewährte Methode in den Bereichen Fehleranalyse und Qualitätskontrolle. Die Energie der hierbei benutzten Röntgenstrahlung bestimmt die Eindringtiefe der Strahlung und schränkt damit die Grösse und das Material des zu untersuchenden Objektes ein. Für grosse, dichte und schwere Objekte sind Photonenenergien von mehr als einem Megaelektronenvolt (MeV) nötig, um nutzbare Transmissionswerte zu erreichen. Ein wichtiger Faktor für die Qualität hochenergetischer Röntgentomografien ist der Anteil der Streustrahlung auf den CT-Bildern. Röntgenstrahlung kann sowohl im zu untersuchenden Objekt, als auch vom Messinstrument und -umfeld streuen und führt zu einem verfälschten Transmissionsbild. Neben Streueffekten kommt für MeV-Photonen zusätzlich der physikalische Prozess der Paarbildung ins Spiel. Die Auswirkung der einzelnen Streuprozesse auf das Transmissionsbild soll hier untersucht werden. Dafür wird mit Hilfe von Monte-Carlo-Simulationen der Einfluss der verschiedenen Streubeiträge untersucht. Im Gegensatz zu früheren Studien, wird hier nicht nur ein Satz von einfachen geometrischen Objekten aus unterschiedlichen Materialien untersucht, sondern es werden auch vereinfachte Modelle der Komponenten eines CT-Scanners benutzt, um den Beitrag der Streuung verschiedener Systemkomponenten abzuschätzen.
Mechanical properties of hypoeutectic Al-Ni alloys with Al3Ni intermetallics
Authors: Karakulak Erdem , Koç Funda Gül , Yamanoglu Rıdvan , Zeren Muzaffer
Published: June 2016

In this paper, the effect of nickel content on the mechanical properties of aluminum were investigated. High purity Al and Ni were melted in an induction furnace and cast into a metal mold. Microstructural characteristic and mechanical properties of the alloys were studied in detail. The addition of nickel to pure aluminum increased the tensile strength and decreased the elongation at break value of the specimens. Maximum wear resistance was obtained with the addition of 3 wt.-% Ni. Further addition of nickel caused a decrease in wear resistance.
Enhanced surface properties of iron by in situ hard nickel coating
Authors: Yamanoglu Rıdvan , Efendi Erdinc
Published: June 2016

In the current study, hard facing nickel alloy powders were coated in situ on pure iron by uniaxial hot pressing under vacuum atmosphere to improve its hardness and wear properties. The nickel alloy powders were placed onto the iron powders within a graphite die and then sintered at 1000 °C under 40 MPa for 10 minutes. Hardness and wear properties were studied by using a Vickers hardness tester and a ball-on-disk tribometer, respectively. The wear rates of the samples were evaluated using a sliding velocity of 0.13 m × s−1 under normal loads of 20, 30, 40 and 50 N at room temperature. The interface layer between the nickel layer and pure iron substrate was also evaluated by scanning electron microscopy and energy dispersive spectroscopy. The results showed that sintered samples exhibited strong bonding at the interface. The hardness and wear properties of the materials increased effectively after nickel coating.
Mechanical and fracture behavior of B4C reinforced Al composites produced by hot pressing
Authors: Ekici Ergün , Özçatalbaş Yusuf , Gülesin Mahmut
Published: June 2016

In this study, the effects of particle addition on the microstructure, mechanical properties and fracture behaviors of Al/B4C particle reinforced composite produced by hot pressing method were investigated. After the production of 5, 10 and 15 wt.-% of B4C reinforced composites, T6 heat treatment was applied. It was specified that a strong interface bond occurred between the matrix and particles, and during the fracturing of composites, this effect increased the particle fracture. It was observed that particles were fractured parallel to the fracture surface and to each other fracture surface of MMCp. In general, cavity of particle separated from the matrix was not seen. In the production of MMCp, it was also observed that hot pressing provided a density higher than 99 %. After the heat treatment the maximum hardness value of 173 HB was reached with 15 wt.-% B4C reinforced sample. The transverse rupture strength (TRS) decreased with the increase of reinforcement ratio. The highest TRS was 510 MPa with the 5 wt.-% reinforced material, whereas the lowest value was obtained to be 387 MPa with the 15 wt.-% B4C reinforced material.
Effect of hot dip galvanized coating on the corrosion resistance of the external surface of reinforcement steel
Authors: Aydin Özlem , Topuz Polat
Published: June 2016

Studies have been carried out to investigate the performance of hot dip galvanized coating on reinforcement corrosion. The coated and uncoated concrete specimens were subjected to accelerated corrosion to determine the time to corrosion initiation. The accelerated corrosion test results clearly showed that the specimens with hot dip galvanized coatings performed very well against reinforcement corrosion and were better than uncoated specimens.
Post-Disaster Migrations and Returns in Sicily: The 1908 Messina Earthquake and the 1968 Belice Valley Earthquake
Authors: Parrinello Giacomo
Published: June 2016

This article explores the relationship between disasters and the population movements in two case studies: the 1908 Messina earthquake and the 1968 Belice Valley earthquake. While they happened in different areas and at different times, the earthquakes share two major characteristics. First, they caused the almost complete destruction of infrastructure over a large area. Second, they resulted in massive population movements away from the disaster areas. This paper aims to understand the connection between these phenomena, posing a number of questions: Were the population movements permanent or temporary? Were the disasters solely responsible for the movements? Did the demography of the stricken areas recover from the disaster or not? And why, or why not? To answer these questions, the article draws on historical analysis and comparison, following the population movements not only in the immediate aftermath but also over a longer period of time. This method helps in identifying the characteristics of the movements and in assessing whether they were temporary or permanent, where they were directed, and why. The comparison between the two cases, then, allows conclusions to be drawn about the factors that play a role in orienting the postdisaster population movements, and, in the final analysis, in deciding whether people would continue to live in the disaster area or not. As the article illustrates, while the city of Messina recovered from the post-disaster displacements and soon increased its population, the Belice Valley population remained much smaller than in the pre-disaster years. In order to explain that major difference, it is worthwhile to situate the disaster within a broader narrative, taking into account social, economic, and political factors, as well as overall historical processes. The results of this study, therefore, empirically validate analytical models that account for multiple drivers in post-disaster migration and refute any simplistic connection between disaster and population movements. However, the results can also enrich those models by demonstrating the importance of timescale, and the need to integrate it as a pivotal element in the analysis.
Healthy Country, Unhealthy City: Population Growth, Migration, and Urban Sanitation in Lima and Manila
Authors: Soll David
Published: June 2016

This article explores the connection between the significant health improvements made in the developing world, particularly after World War II, and the goal of providing clean water and sanitation services to large urban centers in these countries. Using Manila and Lima as case studies, it argues that increases in life expectancy stemming from reduction in the incidence of infectious diseases led to significant rural population growth, spurring rapid migration to urban areas. This migration in turn created enormous public health challenges in cities. Migrants generally lived in unsanitary informal settlements. In some cases, particularly in the short term, moving to the city posed significant health risks to migrants. However, a combination of activism by migrants and increased managerial competence on the part of urban authorities is beginning to yield an urban health dividend, at least in most Latin American and Asian cities. Drawing on the theories of the demographic transition and the epidemiological transition, this analysis links urban health issues to larger-scale transformations in population and health trends.
Feeding Habit and Length-weight Relationship of a Mudskipper Apocryptes Bato (Hamilton, 1822) from the Coast of Chittagong, Bangladesh
Authors: Rahman Mohammed Sadequer , Rahman Mohammad Mizanur , Parvez Md Sohel , Nabi Md. Rashed Un
Published: June 2016

Diet analysis revealed that Apocryptes bato is a carnivorous fish. It depends on shrimps and non-shrimp crustaceans mainly. Shrimps include Acetes, penaeid and metapenaeid juveniles, whereas non-shrimp crustaceans include copepods, crab larvae, mysids and amphipods predominantly. The total body lengths (TL) varied between 11.20 and 22.20 cm and weight 16.70 to 43.50 g in male fish. The form of the equation for TL and weight relationship was W = 0.44TL2.57 and for standard length (SL) it was W = 1.009SL2.66. Condition factor (K) ranged from 0.87 to 1.23. The TL was 15.00 to 26.00 cm and weight as 25.1 to 38.50 g in female. The equation was W = 1.001TL2.52 for TL and W = 1.003SL2.63 for SL and K value ranged from 0.95 to 1.106. The coefficient of correlation was tested with t test and found highly significant at the 5% level of significance for TL and SL both in the case of male and female.Journal of Bangladesh Academy of Sciences, Vol. 40, No. 1, 57-64, 2016
Association of Pestalotiopsis Guepinii (DESM.) Stay. with Bipolaris Leaf Blight (BpLB) Infected Wheat Leaves-A new Record
Authors: Shamsi Shamim , Momtaz Mst Selina
Published: June 2016

Pestalotiopsis guepinii (Desm.) Stay an anamorphic fungus belonging to the class Celomycetes was isolated from Bipolaris leaf blight (BpLB) infected wheat leaf of two wheat varieties namely, Balaka and Saurab during the period of February to March, 2011. Association of Pestalotiopsis guepinii with wheat is a new record.Journal of Bangladesh Academy of Sciences, Vol. 40, No. 1, 87-90, 2016