bluuebunny/crossref_metadata_2025 huggingface dataset:
Soil CO2 Efflux Responses to Soil Loss on Two Rangeland Ecosystems
Authors: Thorne Mark S. , Trlica M. J. , Leininger Wayne C. ,   Society for Range Management
Published: June 2016

A steady state in soil carbon (C) requires that the production of organic C compounds equal their losses through respiration and erosion. How accelerated rates of soil loss affect this balance in western rangelands, where rates of C accumulation without disturbance are relatively slow, is not well understood. The purpose of this study was to determine the effects of soil loss on total, bare soil, and plant respiration rates at shortgrass prairie and sagebrush steppe sites. The experimental design was a split- plot, randomized block, with a factorial arrangement of treatments. The factor levels consisted of 3 levels of soil removal (0, 11.2, and 22.4 t/ha) and 2 range condition classes (good and fair) with 3 replications each at the shortgrass site. Range condition class was not a factor considered at the sagebrush site. Soil CO2 efflux was measured at weekly intervals during the 1999 and 2000 growing seasons at the shortgrass site but only during the 2000 season at the sagebrush site. Total, bare soil, and plant respiration rates at the sagebrush site varied little (P > 0.10) among the 3 soil removal treatments. While total respiration at the shortgrass site increased significantly (P < 0.10) as soil removal level increased, bare soil respiration did not vary (P > 0.10) among the 3 soil removal levels. Plant respiration rates at the shortgrass site generally increased as soil removal level increased, but this response was affected by environmental factors that influenced plant productivity. Increased total respiration rates observed on the shortgrass prairie resulted primarily from increased plant respiration rather than from changes in bare soil respiration. Thus, changes in plant respiration following disturbance may be more important to total soil CO2 efflux than soil flora and faunal respiration that appeared to be more resistant to disturbance.
Vizcacha’s Influence on Vegetation and Soil in a Wetland of Argentina
Authors: Arias Santiago M. , Quintana Rubén D. , Cagnoni Marcela ,   Society for Range Management
Published: June 2016

We examined the influence of the plains vizcacha (Lagostomus maximus) on the vegetation structure and the characteristics of soil in a wet grassland area of Argentina. This rodent lives in social groups that share a communal burrow system that is occupied for several generations. The areas in which the vizcacha live and feed are strongly affected by grazing, trampling, and soil removal, exhibiting extensive biopedturbation. To evaluate these effects, we carried out a vegetation survey, along areas extending outward from active vizcacheras, analyzing abundance, plant diversity, vegetation cover, and biomass. We also established soil properties, analyzing physical and chemical variables from the center of the colonies to the grassland matrix. Our results show that vizcachas have indeed affected vegetation, diminishing plant cover and grass biomass in their grazing areas. Vegetation in both areas without animal activity and those of intense grazing was dominated by a few characteristic species. We verified the hypothesis of greatest diversity in areas of moderate disturbance. Perturbed areas had higher cation exchange capacity and electric conductivity and higher clay and sodium contents than the other areas. The rodents’ activity introduces a recurrent disturbance factor to the landscape of this region, the outcome of which is the alteration of both the composition and structure of the botanical communities, and some soil properties, scaled in gradients of decreasing effect from the center of a colony to the periphery.
An Evaluation of Arizona Cooperative Extension’s Rangeland Monitoring Program
Authors: Fernandez-Gimenez Maria E. , Ruyle George , McClaran Susan Jorstad ,   Society for Range Management
Published: June 2016

We evaluated Arizona Cooperative Extension’s Rangeland Monitoring Program with the use of focus groups and a self- administered mail survey of grazing permittees and natural resource agency employees. Our primary objectives were to 1) determine whether Extension is reaching its target audience, 2) describe the monitoring practices and attitudes of permittees and agency staff, 3) determine whether there is a relationship between permittees’ exposure to Cooperative Extension and their monitoring and management practices, and 4) identify the monitoring information needs and preferences of permittees and natural resource agency staff. We found that Arizona’s rangeland monitoring Extension program has been effective in reaching a large part of its target audience, and a significant proportion of Arizona permittees monitor on public, private, and state- owned rangelands. However, overall monitoring adoption rates remain low. Extension contact is associated with use of monitoring and other beneficial management practices, and permittees and agency employees report that monitoring increased their knowledge and led to changes in management. Monitoring by permittees improves agency-permittee relationships in many cases. Most permittees and agency employees believe that their respective peers are the most reliable source of monitoring information and prefer to receive information from Extension through face-to-face contact at workshops or personalized on-site assistance. The evaluation revealed important social dimensions of rangeland monitoring. Extension agents play a key role in facilitating the social process of monitoring, as well as providing technical training in monitoring skills. Further study is needed to investigate whether permittee monitoring actually leads to better management, improved economic returns, or increased tenure security.
Clipping Frequency Affects Canopy Volume and Biomass Production in Planeleaf Willow (Salix planifolia var. planifolia Prush)
Authors: Thorne Mark S. , Meiman Paul J. , Skinner Quentin D. ,   Society for Range Management
Published: June 2016

Willows (Salix) are often a key component of riparian ecosystems and are often browsed by both wildlife and livestock. However, little is understood about how the frequency of browsing affects aboveground and belowground willow production. The objectives of this study were to determine how the frequency of simulated browsing events in a controlled environment affected 1) the aboveground, belowground, and total biomass production and 2) the canopy volume of planeleaf willow (Salix planifolia var. planifolia Prush) plants. The experiment was a completely randomized block design consisting of 2 groups of willow plants with different clipping histories. Within each group, plants were randomly assigned to 1 of 11 subgroups. Clipping events comprised of all combinations of early, middle, and late season periods were imposed on the treatment subgroups, while 1 subgroup served as the control. Canopy volume measurements were made before and after each clipping event. Canopy volume change was related to the harvested twig length (cm) and weight (g). Results suggested that frequency of clipping alone did not explain differences in aboveground and belowground willow production. Instead, willow production was influenced by an accumulation of specific combinations of seasonal clipping events and was dependent on the clipping history of the plants. Early season clipping, alone or in combination with other events, was more detrimental to willows with prior clipping histories than middle or late season clipping treatments. Willow with prior clipping histories treated in either the middle or late seasons, and the late/middle combination produced more than the controls. These results should be verified in willow communities subjected to natural environmental variations and browsing.
State-and-Transition Models, Thresholds, and Rangeland Health: A Synthesis of Ecological Concepts and Perspectives
Authors: Briske D. D. , Fuhlendorf S. D. , Smeins F. E. ,   Society for Range Management
Published: June 2016

This article synthesizes the ecological concepts and perspectives underpinning the development and application of state-and-transition models, thresholds, and rangeland health. Introduction of the multiple stable state concept paved the way for the development of these alternative evaluation procedures by hypothesizing that multiple stable plant communities can potentially occupy individual ecological sites. Vegetation evaluation procedures must be able to assess continuous and reversible as well as discontinuous and nonreversible vegetation dynamics because both patterns occur and neither pattern alone provides a complete assessment of vegetation dynamics on all rangelands. Continuous and reversible vegetation dynamics prevail within stable vegetation states, whereas discontinuous and nonreversible dynamics occur when thresholds are surpassed and one stable state replaces another. State-and-transition models can accommodate both categories of vegetation dynamics because they represent vegetation change along several axes, including fire regimes, weather variability, and management prescriptions, in addition to the succession-grazing axis associated with the traditional range model. Ecological thresholds have become a focal point ofstate-and-transition models because threshold identification is necessary for recognition of the various stable plant communities than can potentially occupy an ecological site. Thresholds are difficult to define and quantify because they represent a complex series of interacting components, rather than discrete boundaries in time and space. Threshold components can be categorized broadly as structural and functional based on compositional and spatial vegetation attributes, and on modification of ecosystem processes, respectively. State-and-transition models and rangeland health procedures have developed in parallel, rather than as components of an integrated framework, because the two procedures primarily rely on structural and functional thresholds, respectively. It may be prudent for rangeland professionals to consider the introduction of these alternative evaluation procedures as the beginning of a long-term developmental process, rather than as an end point marked by the adoption of an alternative set of standardized evaluation procedures.
Wyoming Big Sagebrush Recovery and Understory Response With Tebuthiuron Control
Authors: McDaniel Kirk C. , Torell L. Allen , Ochoa Carlos G. ,   Society for Range Management
Published: June 2016

Field data collected over a 20-year period at 8 sites in northwestern New Mexico was used to determine Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis Beetle and Young) recovery following control with tebuthiuron (N-[5-(1,1- dimethylethyl)-1,3,4-thiadiazol-2-yl]-N-N9-dimethylurea) and to relate understory perennial grass yield to overstory canopy cover. Tebuthiuron killed between 80% and 95% of mature Wyoming big sagebrush plants within 18 months of chemical treatment, but through recruitment plant numbers equaled or exceeded pretreatment density (plants/m2) at 3 of the 8 sites and were increasing at other locations near the study’s end. Wyoming big sagebrush canopy cover averaged <2% the first 10 years after herbicide treatment but had returned to near pretreatment levels (>15%) at 2 sites, to between 5% and 10% at 4 sites, and to less than 3% at the remaining 2 sites. Treatment life was projected to exceed 35 years for 6 of the 8 study sites. Higher rates of tebuthiuron generally extended treatment life. Annual average perennial grass yield increased on treated areas relative to untreated rangeland at all study sites over the 20-year study period. Grass yield was highly variable between years, with pronounced increases when weather and environmental conditions were favorable for grass growth. A nonlinear S-shaped curve best described overstory-understory relationships and also defined the time path of Wyoming big sagebrush recovery, which differed by study site.
Understanding Landscape Use Patterns of Livestock as a Consequence of Foraging Behavior
Authors: Launchbaugh Karen L. , Howery Larry D. ,   Society for Range Management
Published: June 2016

Many grazing-management challenges stem from poor livestock distribution resulting in overuse of some areas and low utilization of others. Managing livestock-distribution patterns requires knowledge of pasture characteristics and animal behavior patterns. Behavioral patterns result from recognizable processes that include inherited attributes, individual and social learning systems, cue-consequence specificity, predispositions toward novel stimuli, and spatial memory. Through these behavioral mechanisms, animals form and revise preferences and aversions for specific locations in their foraging landscape. To accomplish habitat selection, domestic herbivores use sight and sound cues to seek and return to high-quality foraging locations. Nested within habitat selection are learned diet preferences and aversions by which ungulate herbivores associate taste with positive or negative postingestive feedback. The deliberate and careful modification of animal attributes and habitat characteristics could yield options for adaptive rangeland management. In this article, we describe the basic principles that underlie how animals make decisions about where to forage and how long to stay in a particular habitat. We also suggest management practices designed to modify animal behavior and alter habitat-use patterns.
Development of Agitators for Seeding Forages Using Air Delivery Systems
Authors: McCartney Duane , Hultgreen Gord , Boyden Allan ,   Society for Range Management
Published: June 2016

Air seeders or air drills traditionally have been used for minimum till and direct seeding of cereal, oilseed, and pulse crops. These seeders use an air delivery system to move the seed from a large grain tank to cultivator furrow openers or boots. Air seeders have all the weight of the cultivator attachment on wheels, whereas the air drill cultivator attachment has the weight distributed to caster wheels on the front and the packer wheels on the back. These units have not been used extensively for forage seeding because of seed bridging problems with some types of grass seed over the metering system entry points in the seed tank. This study designed and evaluated modifications to the agitation and metering systems for seeding forages using 3 different types of Canadian-built air seeders. Meadow brome grass (Bromus riparius Rehmann) was used in the seeding trials because of its extreme susceptibility to bridging. The agitator systems for 3 different types of commercially available air seeders were modified with the ultimate goal to design a configuration that reduced seed bridging and provided uniform seed output. Tests were also conducted with a seed and fertilizer mixture as another method of improving uniformity of seed metering and output. None of the air seeders were able to meter and distribute pure meadow brome seed without the use of a modified agitation system. The Bourgault 3165 air seeder was able to effectively meter and distribute the meadow brome grass seed and fertilizer mixture without the agitator modifications and was able to meter and distribute pure meadow brome grass seed with the addition of the modified agitator. The Flexi-coil 172 air seeders required the addition of a horizontal agitator to effectively meter and distribute the seed and fertilizer mixture, and the Morris 6130 was unable to output the mixture of meadow brome grass seed and fertilizer uniformly despite agitator modifications. Field-scale testing indicated that grass forages could be successfully seeded using a full- size air seeder with these modifications.
Diet Composition, Forage Selection, and Potential for Forage Competition Among Elk, Deer, and Livestock on Aspen-Sagebrush Summer Range
Authors: Beck Jeffrey L. , Peek James M. ,   Society for Range Management
Published: June 2016

We evaluated elk (Cervus elaphus), mule deer (Odocoileus hemionus), cattle (Bos taurus), and domestic sheep (Ovis aries) diet composition, diet overlap, and forage selection on aspen (Populus tremuloides Michaux)-sagebrush (Artemisia spp. L.) summer range in northeastern Nevada to understand potential for forage competition to provide better information for managing these communities. Diets were determined through microhistological fecal analysis from 1998 to 2000, and forage selection was evaluated at feeding sites in aspen and sagebrush communities in 1999 and 2000. Elk spring diets were the most diverse in composition; summer elk diets were dominated by forbs (59%-78%); deer consumed mostly woody browse (64%-72%); and cattle and sheep ate mostly graminoids. Lupines (Lupinus spp. L.) constituted > 11% of elk, deer, and sheep diets in summer. Spurred lupine (Lupinus caudatus Kellogg) was the lupine typically selected in feeding sites and greatest consumption occurred in summer when total alkaloid levels were lowest. Highest diet overlap was between cattle and sheep in 1999 (68%) and lowest between deer and cattle in 2000 (3%). Summer elk and deer diets overlapped moderately (45%-59%). Diets did not differ between elk in spring with sheep, elk in summer with deer and sheep, or cattle with sheep. Cattle foraged selectively on forbs in aspen communities (68%) and on graminoids in sagebrush communities (88%), reflecting relative forage availabilities. We detected no differences among elk, cattle, and sheep for forage selection in aspen communities. Electivity indices indicated elk preferred forbs in aspen and sagebrush communities; cattle preferred graminoids in sagebrush; and foraging sheep preferred forbs in aspen. Our results suggest potential for forage competition among ungulates on aspen-sagebrush summer range is highest for forbs in aspen communities. Monitoring productivity and use of key forage species, particularly forbs in aspen communities, should complement management objectives on shared aspen-sagebrush summer range.
Using Geographic Information Systems to Present Nongeographical Data: An Example Using 2-Way Thermogradient Plate Data
Authors: Tarasoff Catherine S. , Louhaichi Mounir , Mallory-Smith Carol ,   Society for Range Management
Published: June 2016

‘‘A picture is worth a thousand words’’ is a familiar truism that is aptly suited to the dilemma of presenting complex research results involving multiple explanatory variables. An example of such a scenario is the use of 2-way thermogradient plates to study optimal germination temperatures and germination over time to answer a variety of biological questions. Two-way thermogradient plates produce a plethora of seed germination data, the value of which quickly becomes obscured in cumbersome tabular data formats. Problems related to comprehensible data presentation can swell when germination over time is incorporated into an experiment. Although somewhat unorthodox, Geographic Information Systems-based techniques are powerful tools that provide a clear and visually evident presentation of seed germination data to the reader.
Brome Control and Microbial Inoculation Effects in Reclaimed Cool-Season Grasslands
Authors: Stacy M. Dean , Perryman Barry L. , Stahl Peter D. ,   Society for Range Management
Published: June 2016

Introduction and subsequent invasion of smooth brome (Bromus inermis Leyss.) into native cool- and warm-season grassland communities has become problematic where presence of native species is important or mandated. The objectives of this study were to examine the efficacy of burning, grazing, and herbicide to reduce smooth brome production and cover while minimizing coincident detrimental effects on cool-season grasses in a reclaimed surface coal mine site. Concurrently, the project also investigated effects of microbial inoculation on respread topsoil subjected to long-term storage and associated effects on seeded cool-season grasses subjected to brome control treatments. Results indicated that grazing and burning were most effective after 2 years of treatment. Smooth brome biomass was lowest in reburned cells (mean +/- SE, 189 +/- 77 kg ha-1) followed by regrazed (294 +/- 129) compared to untreated cells (824 +/- 42) (P < 0.0001). Native grass production was highest in grazed cells (141 +/- 67 kg ha-1) followed by burning (104 +/- 41), herbicide (72 +/- 30), and untreated (30 +/- 27). Foliar cover response patterns were similar. Inoculation had little effect on microbial biomass and mycorrhizal infection. Retreated cells did show differences among months (P = 0.013) in 2000, and microbial carbon ranged from 0.07 +/- 0.01 mg/g in June to 0.12 +/- 0.01 in July and 0.12 +/- 0.01 in August, averaged across treatments. Root infection decreased as soil moisture declined. Results indicate grazing offers the greatest potential for controlling smooth brome without harming native, seeded grasses on reclaimed lands in northern mixed- prarie communities, and inoculation was unnecessary for enhancing seeded, cool-season grass growth.
The Use of Brush Management Methods: A Texas Landowner Survey
Authors: Kreuter Urs P. , Amestoy Heidi E. , Kothmann Mort M. ,   Society for Range Management
Published: June 2016

Adoption of effective brush management methods is critical to achieving many rangeland management objectives. However, landowners have often been reluctant to adopt new practices. In April 2000, a questionnaire was mailed to the 1058 landowners in 48 Texas counties to identify factors that influence land management decisions, especially with respect to brush management practices, including Brush Busters treatments. Brush Busters is a Texas-based program developed to expedite the adoption of ‘‘select’’ individual plant treatments through the use of environmentally safe methods. Overall, landowners were ‘‘neutral’’ to ‘‘dissatisfied’’ with regard to the amount of brush on their land. Two primary reasons for wanting to decrease brush were to increase forage production and to conserve water. Kind of brush and cost of brush control were important factors determining the preferred treatment type. In general, the most effective methods were considered to be mechanical treatments for juniper (Juniperus ashei) and individual plant herbicide treatments for mesquite (Prosopis glandulosa) and prickly pear (Opuntiaspp.). Mechanical treatments and aerial herbicide applications were perceived to be the most expensive methods, followed by individual plant herbicide treatments, and fire was considered to be the least expensive method. Our study indicated that landowners’ satisfaction with Brush Busters’ select methods will likely result in an increase in the use of individual plant herbicide treatments for controlling brush. Our study emphasized that a key for enhancing the adoption of sound rangeland management practices is the development and effective dissemination of user-friendly information about low-cost techniques that produce quick results. Easily visible demonstration sites and the establishment of cooperative groups could accelerate the adoption of such practices.
Seedling Growth of Two Honey Mesquite Varieties Under CO2 Enrichment
Authors: Derner Justin D. , Tischler Charles R. , Polley H. Wayne ,   Society for Range Management
Published: June 2016

Seedlings of 2 varieties of honey mesquite (Prosopis glandulosa var. glandulosa and P. glandulosa var. torreyana) were exposed to 2 concentrations of atmospheric carbon dioxide (CO2) (368 and 704 μmol mol-1) in environmentally controlled glasshouses under near-optimal temperature and soil water conditions to determine if CO2 enrichment alters above- and belowground growth responses. CO2 enrichment substantially enhanced both above- and belowground growth variables of both varieties for all harvest dates (8, 16, and 24 days postemergence). This growth enhancement was greater for aboveground variables (21%- 35%) at the first harvest, greater for belowground variables (36%-40%) at the second harvest, and similar for both above- (13%-68%) and belowground (10%-40%) variables at the last harvest. Differences in temporal growth enhancement associated with CO2 enrichment suggest changing carbon allocation priorities, with initial carbon investment allocated primarily aboveground to develop photosynthetic machinery, and later carbon allocations predominately directed toward increased investment in roots. The absence of significant CO2 X variety interactions at any harvest date provides evidence that CO2 enrichment did not exaggerate growth responses between the 2 varieties. These results suggest that varietal differences in rooting and other characteristics did not modify the size advantage of the glandulosa over the torreyana variety, as the absolute differences in sizes did not change as a function of CO2 treatment. Although CO2 enrichment did not exaggerate growth differences between varieties in this species, it is evident that honey mesquite seedlings possess the capacity to respond markedly to CO2 enrichment. The greater root depth of honey mesquite seedlings exposed to CO2 enrichment confers a competitive advantage to mesquite seedlings over grass seedlings, assuming that C3 and C4 grass seedlings will not respond as vigorously to CO2 enrichment. As such, this species should continue to aggressively encroach into grasslands in future CO2-enriched environments.
Nutritive Value of Desmanthus Associated With Kleingrass During the Establishment Year
Authors: Gonzalez-V E. A. , Hussey M. A. , Ortega-S J. A. ,   Society for Range Management
Published: June 2016

Seasonal variation in production and quality of warm-season grasses is a limitation for livestock productivity. The use of high quality forage legumes to aid in overcoming this problem can be a management alternative. The objective of this study was to evaluate the nutrient content of kleingrass (Panicum coloratum L.)-bundleflower (Desmanthus sp.) mixtures during the establishment year. Plots were drilled at a 0.15 m row-spacing with kleingrass sown either alone or in association with Illinois bundleflower (Desmanthus illinoensis [Michx.] MacM.) or desmanthus (Desmanthus pubescens [L.] Willd), which was previously identified as Desmanthus virgatus. Spacings of 0.30, 0.60, and 0.90 m between rows of bundleflower were used. Plots were planted in April and nutritive value was determined on samples harvested at 60, 90, and 120 days after planting. Age reduced kleingrass crude protein (CP) and increased fiber concentration. The CP concentration of desmanthus leaves was greater than that of Illinois bundleflower; however, the CP on a whole-plant basis was greater in Illinois bundleflower. Associations had greater CP yield than did the kleingrass monoculture. The tannin content was higher in desmanthus than in Illinois bundleflower. In both legumes the leaves had the greatest tannin concentrations, with a mean of 2.1% and 1.69% in desmanthus and Illinois bundleflower, respectively. With the exception of calcium (Ca), mineral content declined with increased age in both legumes and the grass. Levels of potassium, sodium, copper, and manganese were greater in kleingrass than in the legumes, while the legumes had greater concentrations of Ca and magnesium (Mg). Phosphorus and zinc concentrations were similar for kleingrass and legumes. The legumes did not affect the nutrient content of kleingrass when established in association, and the high CP of both legumes and their high levels of Ca and Mg suggest that animals grazing kleingrass-desmanthus associations may benefit nutritionally.
Sire Influence on Juniper Consumption by Goats
Authors: Ellis Chad R. , Jones Royce E. , Scott Cody B. ,   Society for Range Management
Published: June 2016

Goats avoid eating redberry juniper (Juniperus pinchottii Sudw.) when other palatable forages are available but will increase intake of juniper when exposed to the plant for several days. Intake of redberry juniper also differs among breeds and individual goats. Selection based on foraging habits could further improve juniper intake. The purpose of this study was to determine the influence of sires on juniper consumption. Heritability of redberry juniper intake was assessed for 3 years (1997, 1998, 2000) by placing male Boer-Spanish cross goats from 4-8 sires (the number of sires differed among years) in individual pens and feeding juniper (200 g) daily for 2 hours over 5 to 10 days. Feeding juniper was done after weaning kid goats each year. Juniper intake was similar among sire groups within years. Heritability of juniper consumption was low (11%) across the 3 years of this study. Goats increased juniper intake daily while in individual pens. These results suggest that an acceptance of juniper by goats can be conditioned through exposure to the plant after weaning, and that juniper consumption does not appear to be a highly heritable trait.
Vegetation Cover and Forb Responses to Cattle Exclusion: Implications for Pronghorn
Authors: Loeser Matthew R. , Mezulis Sharon D. , Sisk Thomas D. ,   Society for Range Management
Published: June 2016

Cattle grazing is often implicated as a factor that reduces vegetative cover and the abundance of important forage plants for wildlife. Recent declines in northern Arizona populations of pronghorn (Antilocapra americana Ord) have focused public and scientific attention on the factors contributing to low fawn recruitment and the potential benefits of cattle removal. To further understand the effects of cattle grazing, we studied the potential hiding cover provided by standing live and dead herbaceous matter as well as forb richness and canopy cover following 5 years of cattle removal. Cattle removal increased horizontal hiding cover by 8% at a distance of 5 m (P = 0.025), but had no statistically significant effect on the potential hiding cover at distances of 10 m (P = 0.105) or 25 m (P = 0.746). Forb species richness was 16% lower in exclosures than in an adjacent grazed pasture in 2001 (P = 0.036), but no differences were observed in 2002 (P = 0.636). The canopy cover of forbs was generally unaffected by cattle removal. These results suggest that curtailing or removing cattle is unlikely, by itself, to lead to rapid improvements in the hiding cover or forb availability for pronghorn on similar rangelands in northern Arizona. In this region, where immediate improvements in fawn survival and recruitment are important to population persistence, additional management actions should be considered.
Interspecific Competition Interacts with the Spatial Distribution of a Palatable Grass to Reduce Its Recruitment
Authors: Cipriotti Pablo A. , Aguiar Martín R. ,   Society for Range Management
Published: June 2016

Most arid and semiarid ecosystems around the world have been grazed by domestic herbivores. In many cases, grazing has degraded vegetation and soil. The possibility of restoring rangeland’s good condition depends, partially, on the ability of remaining populations of desirable species to recover. In this work, we studied the exact spatial distribution of remaining palatable adult plants in fields with different grazing history (i.e., seed sources) and quantified the effect of interspecific competition with less palatable grasses on seedling emergence and survival (i.e., regeneration constraints). We worked in a Patagonian steppe composed of shrubs and perennial tussock grasses that has been grazed by sheep for >100 years. In order to evaluate the location of seed sources, we mapped the location of a palatable species (Bromus pictus Hook.) in paddocks with different long-term grazing intensity. In addition, we sowed seeds of B. pictus close to 2 dominant, less palatable grasses in 2 different years to evaluate the role of interspecific interactions on regeneration and the effects of climate variability. The proportion of B. pictus plants growing in protected places near less palatable species significantly increased with grazing intensity. Competition effects on emergence, survival, and growth depended on the year’s moisture regime. During the dry year, competition with less palatable grasses reduced the emergence, survival, height, and number of leaves of palatable grass seedlings by 30%, 55%, 48%, and 40%, respectively. In the wet year, there were no effects of competition on emergence and height, and the effects on survival depended on the species of the less palatable neighbors. Our study supports the idea that management for recovering degraded rangelands in this ecosystem may benefit from considering the spatial distribution of remaining plants. It also indicates that the susceptibility of demographic processes to interspecific competition depends on the year and neighbor species.
The Effects of Livestock on California Ground Squirrels (Spermophilus beecheyii)
Authors: Fehmi Jeffrey S. , Russo Sabrina E. , Bartolome James W. ,   Society for Range Management
Published: June 2016

Understanding the impacts of livestock grazing on wildlands is important for making appropriate ecosystem management decisions. Using livestock exclosures, we examined the effects of moderate cattle grazing on the abundance of California ground squirrels (Spermophilus beecheyii Richardson) and the spatial distribution of active burrows within their colonies in grassland and blue oak (Quercus douglasii Hook. Arn.) savanna habitats in the coastal range of California over a 3-year period (1991-1994). Overall, relative population densities of California ground squirrels declined significantly throughout the experiment, but did not differ between grazed and ungrazed colonies or between habitats. There was also no significant interaction between these 2 factors. The spatial distribution of burrows, as measured by the mean nearest neighbor distance of active entrances within a colony, did not differ significantly between grazed and ungrazed colonies or between habitats, nor was the interaction significant. Thus, low to moderate levels of cattle grazing did not appear to have a strong effect on the population dynamics of California ground squirrels, and grazing may be compatible with maintenance of ground squirrel populations. Based on multivariate analysis of variance of 1994 data, live plant cover, native plant cover, and standing biomass were lower where the number of burrows was higher on grazed colonies but were little affected on ungrazed colonies. Ground squirrels may increase the impact of livestock grazing and thus reduce the capacity of the land to support other activities. However, it is clear that the effects of livestock grazing are complex and that detailed studies of potential mechanisms by which grazing impacts California ground squirrel populations are necessary.
Book Review: Tending Fire: Coping with America’s Wildland Fires, Stephen J. Pyne
Authors: Eldred Andy ,   Society for Range Management
Published: June 2016

Book Review: Tending Fire: Coping with America’s Wildland Fires, Stephen J. Pyne. Island Press, Washington, DC (2004).
Feeding Value of Singed Walkingstick Cholla
Authors: Sawyer Jason E. , Endecott Rachel L. , Löest Clint A. ,   Society for Range Management
Published: June 2016

Walkingstick cholla cactus (Opuntia imbricata [Haw.] DC) has been used in New Mexico as an emergency feed during drought for more than 100 years. Most reports present only the chemical composition of walkingstick cholla, and limited data exist regarding its feeding value. Three wethers (avg wt 65 +/- 7 kg) were fed a basal diet of mature blue grama hay (Bouteloua gracilis [HBK] Lag. ex Steud., 9.0% crude protein [CP] and 69.0% neutral detergent fiber [NDF], organic matter [OM] basis) in a replicated 3 X 3 Latin square to determine digestibility of singed walkingstick cholla and to measure nitrogen balance. Treatments consisted of 0%, 15%, and 20% walkingstick cholla in the diet on a dry matter (DM) basis. Walkingstick cholla contained 20.3% DM, 79.6% OM, 36.4% NDF, and 9.0% CP (OM basis). Walkingstick cholla clippings, consisting of green, nonwoody cladodes, were harvested in September. Cactus was singed with a propane torch until no spines remained, chopped, and added to the diet each day. Walkingstick cholla and hay were sampled daily and compiled by period. Total fecal and urine collections were subsampled and frozen for later analysis. Feed and fecal samples were analyzed for DM, OM, NDF, and nitrogen (N); urine samples were analyzed for N. Nutrient digestibilities and N-retention values were calculated. Walkingstick cholla digestibilities were determined by difference. Mean walkingstick cholla DM, OM, NDF, and CP digestibilities averaged 32.6%, 44.3%, 27.9% and 67.6%, respectively. Diet OM and CP digestibilities were similar for all treatments. Diet DM digestibility tended (P = 0.08) to decrease linearly with increasing dietary walkingstick cholla. As walkingstick cholla increased in the diet, NDF digestibility decreased linearly (P = 0.04). Because of its poor feeding value and low DM content, use of walkingstick cholla as an emergency feed should be carefully considered.
Fall-Prescribed Burn and Spring-Applied Herbicide Effects on Canada Thistle Control and Soil Seedbank in a Northern Mixed-Grass Prairie
Authors: Travnicek Andrea J. , Lym Rodney G. , Prosser Chad ,   Society for Range Management
Published: June 2016

Prescribed burning in Theodore Roosevelt National Park has played an important role in maintaining a natural ecosystem. However, changes in plant community dynamics caused by burning may have led to an invasion of weedy species such as Canada thistle (Cirsium arvense L.). The objectives of this research were to evaluate the effect of a fall burn before spring herbicide application on Canada thistle control and to evaluate the soil seedbank within Canada thistle infestations. Canada thistle stem densities initially were higher in the burned compared with the nonburned areas because plants were slower to emerge in the nonburned treatments. However, the effect was short-lived, and Canada thistle densities were similar in the burned and nonburned treatments by the second season following the prescribed burn. Canada thistle control averaged 78% 60 days after treatment with clopyralid, clopyralid plus triclopyr, or picloram when spring applied whether or not application was preceded by a prescribed burn. Control declined to less than 60% by 363 days after application. Grass cover increased from an average of 5% before treatment to 37% and 46% 60 and 425 days after herbicide application, respectively, regardless of burn treatment. Forb cover increased following a prescribed burn but was unaffected by herbicide treatment. Overall the number and variety of species in the soil seedbank was not affected by a prescribed burn. A total of 74 species (56 forbs, 13 grasses, and 5 other mesic species) were found in the soil seedbank. However, the majority of the soil seedbank consisted of nondesirable low seral and invasive species including Canada thistle and Kentucky bluegrass (Poa pratensis L.), which accounted for over 80% of the total germinated seed. Although a prescribed burn caused an initial increase in Canada thistle density and cover, the greater long-term concern may be the lack of desirable species present in the seedbank to replace Canada thistle once the weed is controlled.
Perceived Effectiveness of Livestock-Guarding Dogs Placed on Namibian Farms
Authors: Marker Laurie L. , Dickman Amy J. , Macdonald David W. ,   Society for Range Management
Published: June 2016

Evaluations of117 livestock-guarding dogs placed on Namibian farms between January 1994 and November 2001 were conducted as part of a study aimed at reducing livestock depredation rates on both commercial and communal farmland. The perceptions of livestock farmers were evaluated in terms of their satisfaction with the guarding dogs, the level of care given to the dogs, and the attentiveness, trustworthiness, and protectiveness of the dogs. Guarding dogs were very successful in terms of reducing livestock losses, with 73% of responding farmers reporting a large decline in losses since acquisition of a guarding dog, and the same percentage seeing an economic benefit to having the dog. Farmer satisfaction with the dogs was high, with 93% of farmers willing to recommend the program, and the care given to the dogs was also good. The dogs exhibited high levels of protectiveness and attentiveness, although trustworthiness was relatively low. The level of care provided by farmers was lower for older dogs than for younger dogs, and older dogs appeared to be less trustworthy than young dogs. There were no obvious differences in effectiveness between the sexes, or between dogs placed on communal farms and those on commercial ranches.The majority of dogs exhibited behavioral problems at some stage, particularly chasing game, staying at home, and harassing livestock, but corrective training solved 61% of the reported problems. We conclude that with the correct training and care, livestock-guarding dogs can be an effective method of livestock protection on Namibian farmlands
Arizona Permittee and Land Management Agency Employee Attitudes Toward Rangeland Monitoring by Permittees
Authors: Fernandez-Giminez Maria E. , McClaran Susan Jorstad , Ruyle George ,   Society for Range Management
Published: June 2016

Ongoing conflicts over the management of western rangelands can be attributed in part to the lack of reliable information about current ecological conditions and their causes due, in turn, to insufficient monitoring. To meet the monitoring shortfall, land management agencies increasingly are enlisting permittees to monitor their grazing allotments. We surveyed grazing permittees in 5 Arizona counties and land management agency employees throughout Arizona to compare their attitudes toward permittee monitoring on public rangelands, the role of government in rangeland management, rangeland conditions in Arizona, and the credibility of information sources about rangelands. Permittees and agency employees differed in most of the attitudes measured by our survey. However, both populations agreed that permittees should participate in monitoring their allotments, and many respondents agreed with making permittee monitoring mandatory. Many respondents in both groups also agreed that collaboration can be beneficial. Joint monitoring, which can be considered a type of ‘‘joint fact-finding,’’ may help improve agency-permittee relationships and bridge the gap in attitudes and underlying values. Permittee-monitoring programs deserve careful evaluation to determine their impacts on social relationships, management decisions, and ecological conditions
Remote Sensing Assessment of Paspalum quadrifarium Grasslands in the Flooding Pampa, Argentina
Authors: Herrera Lorena P. , Hermida Vanina Gómez , Martínez Gustavo A. ,   Society for Range Management
Published: June 2016

The knowledge of the distribution, area, and current conservation status of relict natural grasslands dominated by the tall-tussock grass Paspalum quadrifarium Lam. (‘‘pajonal’’) in the Flooding Pampa (Argentina) is relevant for the identification of conservation sites and sustainable management and land-use planning. Since European settlement, vast areas of pajonal were converted to croplands and short-grass prairies. The only available vegetation map of these grasslands was made in the mid-20th century. We evaluated 2 methods of land-cover classification (supervised and unsupervised) using a Landsat TM satellite image over an area of 2 258.21 km2 in Ayacucho county, where pajonal still persists as an important ecosystem. At the paddock scale, this grassland community presents a complex structure in which the pajonal is not a pure category but a mosaic of tall and short grasses. Six categories of land cover were adopted (crops, sown pastures, short grasses, pajonal, wetlands, and urban areas). A very good overall accuracy was obtained for both classifications (86.9% and 87.9% for supervised and unsupervised classifications, respectively). However, both producer’s and user’s accuracies for the pajonal and short grasses were better for the unsupervised classification than for the supervised classification. The pajonal class occupied only 20% of the study area with patch size ranging between 0.09 and 1 653 ha. This work suggests an important replacement of tall-tussock grass by short-grass matrix, which represents noticeable structural and functional changes. The unsupervised classification of Landsat image seems a particularly suitable method for mapping complex vegetation units like the highly fragmented pajonal of the Flooding Pampa and should be an important tool for management and tracking future changes.
Diets of Prairie Dogs, Goats, and Sheep on a Desert Rangeland
Authors: Mellado Miguel , Olvera Abundio , Quero Adrián ,   Society for Range Management
Published: June 2016

Diets of prairie dogs, goats, and sheep were examined by microhistological fecal analysis during 4 periods of a year in a desert rangeland in northern Mexico. Prairie dogs selected more grasses (79% across all seasons; P < 0.05) than goats and sheep during most of the year. Total grasses in goat diets were consistent (20%) in all seasons, whereas this forage class was highest during winter (72%) and lowest during summer (62%) in sheep diets. The diet of goats was predominantly shrubs (45%-62%) in all seasons, whereas sheep and prairie dogs ate little browse throughout the study. All 3 species preferred forbs, which contributed about one-third to the composition of the prairie dog (winter), goat (summer), and sheep (spring) diets. Acacia greggii Gray and Opuntia rastrera Weber were the most preferred species by goats, whereas prairie dogs and sheep showed particular preference for Buchloe dactyloides (Nutt.) Engelm. and Bouteloua gracilis (Willd. ex Kunth) Lag. ex Griffiths. During summer and spring, concentration of nitrogen in the feces of sheep was 36% and 17% higher (P < 0.05) than in the feces of goats. There was a high overlap in diets between prairie dog and sheep in all seasons, whereas diets of prairie dogs and goats, and goats and sheep were significantly different from each other in all seasons. These results showed that competition was keen between prairie dogs and sheep for a limited quantity of forage in this arid zone pasture, whereas goats were better able to use common resources with prairie dogs.
Spring Growth and Use of Cool-Season Graminoids in the Nebraska Sandhills
Authors: Volesky Jerry D. , Schacht Walter H. , Reece Patrick E. ,   Society for Range Management
Published: June 2016

Upland sites in the Nebraska Sandhills are dominated by warm-season grasses, although cool-season graminoids often produce from 10% to 40% of the herbage. The grazing season on uplands traditionally begins when warm-season grasses have initiated rapid growth, which coincides with declining nutrient density of cool-season plants. Earlier initiation of grazing would improve the efficiency of use of cool-season plants. A study was conducted in 2001 and 2002 to characterize the growth of cool-season species on upland range and to determine the use and herbage production in response to spring grazing date and stocking rate. Grazing dates were 10 April, 1 May, and 22 May, combined with stocking rates of 3, 6, and 9 AUD (animal unit days) ha-1. Needleandthread (Stipa comata Trin. Rupr.) and sedges (Carex spp.) accounted for an average of 48% of the spring herbage yield. Amount of total current-year herbage ranged from 114 to 472 kg ha-1 over the grazing dates. Overall, paddock use of needleandthread and sedges averaged 11% and 4%, respectively. Use on 10 April averaged 61% of that observed on 1 and 22 May, likely because of short plant height (5 cm). Residual (prior-year) herbage probably was a substantial component of animal diets on 10 April. Increasing stocking rate resulted in greater herbage use (% weight removed) and percentage of plants grazed (P < 0.1). Total herbage yield in mid-June (1 130 kg ha-1) and mid-August (1 350 kg ha-1) was greatest when paddocks were grazed in April, and it declined by approximately 20% when grazed in May (P < 0.1). Overall, upland grazing strategies that include a grazing period in early May will result in greater utilization of cool-season species, but summer yield will be reduced. However, utilization of cool-season species in the spring would be advantageous, because they are being consumed at a time when their nutritive value and palatability are greater.