Herbivores select plant parts to maximize the quality of their diets. However, there are few procedures available to quantify the relative consumption of leaf blades. In this study, we initially identified epidermal features that were specific of the blade in 4 grasses: Kleingrass (Panicum coloratum L.), tall wheatgrass (Thinopyrum ponticum [Podp.] Barkw. Dewey), tall fescue (Festuca arundinacea Schreb.), and salt grass (Distichlis scoparia L.). Then, we quantified the percentage of fragments with the blade epidermal feature for each species, evaluating whether they varied with plant maturity. We also evaluated whether those percentages were affected by digestion to determine if the procedure we propose could be used in diet analysis. Finally, by linear regression, we analyzed whether the relationships between the actual blade dry mass percentages (y) and those estimated by microanalysis (x) were 1:1 in mixes of different plant parts of the individual species as well as in mixed vegetation samples. Digestion affected the percentage of identifiable blade fragments of each species; but, after correction by digestion, all the estimates were accurate (a = 0 and b = 1 in all the regression equations) and precise (r2 > 0.90). Results indicate that epidermal features specific to blades would make it possible to estimate by microanalysis the percentage of this plant part for each species in vegetation samples from pastures composed of few species and also in the diets of herbivores grazing them. Although the proposed procedure was tested in simple systems, it could also be used to estimate the percentage of blades of the dominant species in the diets of herbivores grazing more complex systems.  

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.  

The ability to map the extent of wooded vegetation cover over large areas using remote sensing is important for managing and assessing rangelands. Currently, applied techniques are inadequate because they 1) do not directly measure the amount of land covered by woody plants and rely on low-resolution images, 2) require considerable training-area data to train a classifier, and 3) describe only a limited number of land cover types. This paper presents an innovative methodology for creating a land-cover map that requires little to no traditional, training-area data collection before classification. The procedure combines both high-resolution aerial photography (resampled to 2.5-m pixels) and lower-resolution satellite imagery (30-m pixels) to produce a detailed and easily producible data set. The resulting data set also categorizes regions into a wide variety of land cover types in addition to differing levels of wooded cover. This new methodology was applied to the Upper Guadalupe River watershed in Texas, which is composed of varying amounts of brush cover between herbaceous range and dense cover. Validation by comparison to aerial imagery demonstrated a 74.4% success rate for all land cover classes. Validation was also performed by ground survey for several brush-covered points and showed a 90.0% success rate. As a result of the ground survey, modifications to the methodology were recommended to reduce classification errors and improve the process.  

Mandated uniform topsoil replacement may hinder or prevent compliance with reclamation bond release standards such as canopy cover, aboveground production, shrub density, and diversity. This investigation was conducted at a coal mine in northeastern Wyoming in order to evaluate the relationship between variable topsoil replacement depths of 15, 30, and 56 cm and short-term revegetation success. Vegetation variables of total cover, total vegetation canopy cover, total number of species, and average number of species (based on cover sampling) were determined on both reclaimed and 2 native reference areas (Upland Grass and Breaks Grass) during 2000, 2001, and 2002, with aboveground production being measured in 2002. The highest total number of species encountered based on canopy cover and aboveground production sampling was in the 30-cm reclaimed treatment, many of which were desirable seeded and volunteer perennial grasses and forbs. In 2001, total vegetation cover on the 56-cm reclaimed treatment was significantly greater than on the 15-cm treatment. Comparison of the current study area to a 1991 reclaimed site indicated a consistent general pattern of species establishment. Aboveground production was also higher in the current reclaimed area than in the native reference areas, while total cover and total vegetation cover were lower. Shannon-Wiener H9 values, based on absolute total vegetation canopy cover, were greater in the 30-cm reclaimed treatment; however, a majority of diversity indices indicated that the Breaks Grass native reference area was more diverse than either Upland Grass or Reclaimed sites. From observations made at the North Antelope/Rochelle Mine, a mosaic of different topsoil depths, including the shallow 15- and 30-cm depths as well as the mandated 56-cm depth, creates the broadest range of vegetation response under a standard regime of revegetation practices. Thus, the capacity to replace different thickness of topsoil should be a reclamation practice available to mine operators.  

Forage quality and quantity are important factors affecting livestock production from grazing lands. ‘‘Greenness’’ has been proposed as an indicator of herbage quality in semiarid environments, particularly nitrogen (N) content. The objective of this study was to assess the potential of estimating N content of forage using dead:green ratios and accumulated growing-degree- days (AGDD). Standing crop samples were collected April through October over 3 years from each of 3 replicated grazing regimes on a silty range site in eastern Montana. Samples were sorted into live, current dead, and old dead components, then dried, ground, and analyzed for N content. The AGDD for base temperature 45 degreesF (7.2 degreesC) was calculated from National Oceanic and Atmospheric Administration (NOAA) reported monthly average temperatures for Miles City. An equation to predict percent N in the total standing crop from percent dead forage and AGDD was developed using multiple linear regression. This equation accounted for 75.9% of variation in percent N, and prediction error variance was 0.026. To validate this equation, data were obtained from samples collected from April through September in an independent study of 8 areas on silty and clay- pan range sites grazed during autumn and winter. Samples from these sites were treated and analyzed in the same manner as those used to develop the equation. The developed equation was used to predict percent N for the validation data. The resulting correlation between predicted and actual values was 0.79. The regression coefficient for actual values on predicted values was 0.995 +/- 0.125. The intercept did not differ from 0.0 (P = 0.22), and prediction error variance was 0.042. This equation has utility for predicting N level of forage from Northern Great Plains rangelands.  

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. 

Livestock grazing practices on public and private rangelands throughout the western United States are subject to increasing scrutiny. Much criticism arises from the tendency for livestock to concentrate in riparian areas and to disproportionately use the vegetation to the degree that riparian function and vegetation are compromised. The purpose of this synthesis article is toevaluate grazing-management strategies that encourage beef cattle to use forage resources away from riparian areas and areas where topographical features limit grazing use. Specifically, this paper evaluates individual management strategies and attempts to quantify the changes in distribution patterns and vegetation use. An effective strategy uses water development to encourage uniform distribution. Likewise, timing and duration of grazing have dramatic influences on cattle distribution in riparian andupland range areas. In general, early in the grazing season, when upland forage is green and growing, cattle tend to distribute more uniformly than later in the season, when upland vegetation is dormant and cattle disproportionately use riparian areas. In addition, early in the season, cattle grazing forested rangelands seem to prefer south-facing aspects with more open canopies when compared with late-season distribution patterns when concentration switches to northerly aspects, denser canopies,and more diverse diets. Other factors that appear to influence distribution include cow breed, age, and stage of production. In addition, recent research suggests that as cows age, distribution patterns change: Older cows have been reported to travel further from water than their younger contemporaries as long as adequate forage is available in the uplands. Additional research is needed on beef cattle selection, technological applications, efficient herding practices, supplementation strategies,and whole-range management systems that encourage the sustainable use of rangeland resources. 

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.