bluuebunny/crossref_metadata_2025 huggingface dataset:
Activated charcoal and experience affect intake of juniper by goats
Authors: Bisson M. G. , Scott C. B. , Taylor C. A. ,   Society for Range Management
Published: March 2016

Goats consume juniper, but toxic terpenoids within the plant limit intake. Our objective was to determine if dosing goats with the adsorptive compound activated charcoal would increase juniper consumption. Twenty Boer-cross goats were placed in individual pens; at 0800 hours, 10 were dosed with 1 g kg(-1) body weight (BW) of activated charcoal in an aqueous solution, and 10 were not dosed. Dosing occurred daily for 10 days. Goats were offered redberry juniper (Juniperus pinchotii Sudw.) in Trial 1, ashe juniper (Juniperus ashei Buch.) in Trial 2, and a choice between redberry and ashe juniper in Trial 3. For each trial, juniper was offered to all goats for 2 hours after dosing with activated charcoal. In Trial 1, goats dosed with activated charcoal consumed more (P < 0.05) redberry juniper during the first 5 days of exposure. In Trial 2, activated charcoal did not affect ashe juniper intake. In Trial 3, dosing with activated charcoal did not affect juniper intake. All goats preferred ashe to redberry juniper. Juniper intake increased across days of exposure for Trials 1 and 2, apparently because goats adapted to the terpenoids in juniper through repeated exposure. It appears that activated charcoal will only increase redberry juniper intake during initial exposures.
Drought and grazing III: Root dynamics and germinable seed bank
Authors: Hild A. L. , Karl M. G. , Haferkamp M. R. ,   Society for Range Management
Published: March 2016

Drought and herbivory frequently influence North American rangelands. While these influences may temporarily reduce vegetative cover, their mutual influence on the available seedbanks which might occupy new safe sites is unclear. We examine effects of drought and grazing upon pre- and post-drought plant root distribution and germinable seed bank to determine 1) if the response of root distributions to drought depends upon grazing use and 2) if the presence of germinable seeds is altered significantly by drought and grazing. Using twelve, 5 X 10 m non-weighing lysimeters with an automated rainout shelter, we documented root intercepts in situ using a minirhizotron from 1993-1996. Seed bank samples were incubated in a greenhouse to determine seedling emergence. Roots were fewer in shallow soil layers in grazed plots than ungrazed plots by the end of the study, irrespective of drought. Roots in deeper (Bw horizon) soil layers were fewer during drought, but were not influenced by grazing. Seed bank composition results suggest that perennial grasses were a small portion of the seed bank. Cool-season annual grass seeds accumulated after drought. Without drought, forb seed banks increased with grazing. Thus while shallow roots may decrease during drought, in the year following drought grazing may decrease aboveground net primary production, and allow large accumulations of cool-season annual grass seed in a northern mixed grass prairie.
Escape protein and weaning effects on calves grazing meadow regrowth
Authors: Lardy G. P. , Adams D. C. , Klopfenstein T. J. ,   Society for Range Management
Published: March 2016

Forty spring-born calves grazing subirrigated meadow regrowth after haying in July were assigned to 2 weaning and 2 supplementation treatments in fall of 1995 and 1996. Weaning treatments were weaning on 1 September or nursing during the duration of the trial. Supplementation treatments were no supplement or supplemental undegraded intake protein (UIP). An 80:20 (dry matter basis) blend of sulfite liquor treated soybean meal and feather meal was the source of undegraded intake protein (undegraded intake protein = 45% of supplement dry matter). Supplemented nursing calves received 0.50 kg of supplement daily whereas supplemented weaned calves received 0.91 kg of supplement daily. Weaned and nursing calves grazed subirrigated meadow regrowth throughout the trial. The trials were conducted from 17 October to 18 November 1995 and 5 September to 4 November 1996. Milk intake was measured by the weigh-suckle-weigh technique. Diet samples collected from ruminally cannulated calves after rumen evacuation averaged 12.5% crude protein and 54.8% in vitro organic matter digestibility. No supplementation x weaning management interactions were detected (P > 0.18). Nursing calves had greater weight gains (0.95 vs. 0.59 kg day(-1); P = 0.001) and lower forage intakes (2.36 vs. 2.96 kg day(-1); P = 0.009) than weaned calves. Supplementation with undegraded intake protein increased (P = 0.03) daily gains of calves compared to nonsupplemented calves 0.88 vs 0.66 kg day(-1), respectively. Forage intake as a percentage of body weight tended to be higher in non-supplemented calves (P = 0.09). However, total intake (forage plus supplement) as a percentage of body weight tended to be higher in supplemented calves (P = 0.14). Total intake (kg day(-1)) was greater (P = 0.01) for calves supplemented with undegraded intake protein. Milk intake did not differ between supplemented and unsupplemented calves (P > 0.52). We concluded that subirrigated meadow regrowth forage was limiting in metabolizable protein and that milk represents an important source of metabolizable protein for grazing calves.
Breeding bird responses to juniper woodland expansion
Authors: Rosenstock S. S. , Van Riper C. ,   Society for Range Management
Published: March 2016

In recent times, pinyon (Pinus spp.)-juniper (Juniperus spp.) woodlands have expanded into large portions of the Southwest historically occupied by grassland vegetation. From 1997-1998, we studied responses of breeding birds to one-seed juniper (J. monosperma) woodland expansion at 2 grassland study areas in northern Arizona. We sampled breeding birds in 3 successional stages along a grassland-woodland gradient: un-invaded grassland, grassland undergoing early stages of juniper establishment, and developing woodland. Species composition varied greatly among successional stages and was most different between endpoints of the gradient. Ground-nesting grassland species predominated in uninvaded grassland but declined dramatically as tree density increased. Tree- and cavity-nesting species increased with tree density and were most abundant in developing woodland. Restoration of juniper-invaded grasslands will benefit grassland-obligate birds and other wildlife.
The nutritive quality of cholla cactus as affected by burning
Authors: Sawyer J. E. , Knox L. A. , Donart G. B. ,   Society for Range Management
Published: March 2016

Cholla cactus may serve as an emergency feedstuff for livestock when forage availability is low. A study was conducted at the Corona Range and Livestock Research Center to evaluate the nutritive quality of cholla cactus (Opuntia imbricata) after spine removal. Six samples were collected for each treatment in a completely randomized design. Treatments consisted of spine removal by burning with a propane torch (BURN), or leaving spines intact (UN). Each sample consisted of 2 burned and 2 unburned cladodes from each of 5 plants. One sample from each treatment was weighed immediately after collection and used solely for dry matter (DM) determination. Remaining samples were evaluated for crude protein (CP), organic matter (OM), neutral detergent fiber (NDF), and mineral composition. Rate and extent of ruminal DM and OM disappearance were estimated in situ for 20 and 68 hours in the rumen of each of 2 cannulated cows grazing native rangeland. Dry matter contents of burned and unburned cholla were 12.7% and 12.4% respectively. Crude protein was not affected by burning (P > 0.6; 13.0% UN, 13.6% BURN, SE +/- 0.7). Burning reduced OM (82.4% UN, 81.0% BURN; SE +/- 0.4) and NDF (48.6% UN, 39.2% BURN; SE +/- 1.8) content (P < 0.03). Reduced NDF contributed to increased rate and extent of ruminal OM disappearance for burned cholla (P 0.03). Mineral content was minimally affected by burning. Measurements indicate that cholla has relatively high nutrient quality, but the high moisture content would require large amounts to be fed as an emergency feed source.
Application of non-equilibrium ecology to rangeland riparian zones
Authors: Stringham T. K. , Krueger W. C. , Thomas D. R. ,   Society for Range Management
Published: March 2016

Traditional theories of plant succession leading to a single equilibrium community are being re-evaluated. Alternative theories involving multiple steady states, and state-and-transition processes have been postulated to more adequately reflect the dynamics of rangeland ecosystems. The ecological literature provides examples of apparent thresholds in arid and semi-arid plant communities, however the literature is void of discussion of the applicability of non-equilibrium ecological theory to riparian areas contained within the rangelands of the world. In arid and semi-arid environments the availability of soil water is critical in the determination of the composition of the plant community. In this study we hypothesized that the relationship between soil moisture and depth to groundwater within the riparian zone controlled the composition of the associated plant communities. These soil water, groundwater, plant community composition relationships were used to test the applicability of state and transition models to riparian zones. Water table levels within an irrigated eastern Oregon riparian valley were monitored for 2 consecutive summers. The study area was mapped into 4 distinct plant community types on the basis of dominant graminoids. We measured depth to the water table, soil moisture content, relative species composition, litter, percent bareground and percent relative basal cover of key plant species and life forms. Relationships between water table levels, soil moisture content and plant communities were analyzed. Results indicated the 4 plant communities contained within this study area can be segregated on the basis of soil moisture content and/or depth to groundwater during the growing season. Ecological states and transition zones based on soil moisture content and/or water table depth were determined.
Complementary grazing of native pasture and Old World bluestem
Authors: Gillen R. L. , Berg W. A. ,   Society for Range Management
Published: March 2016

Native pasture and Old World bluestems (Bothriochloa spp.) have contrasting herbage production characteristics that suggest potential for incorporation into a complementary forage system. We compared 2 yearling beef production systems consisting of either native pasture (Native) or Old World bluestem combined with native pasture (Old World bluestem-Native) over 5 years. Crossbred steers (initial weight 257 kg) grazed only native pasture in the Native system, but alternated between Old World bluestem and native pastures in the Old World bluestem-Native system. Production system had no effect on the frequency of any plant species in the native pastures (P > 0.16) even though stocking rate in the growing season was increased 31% in the Old World bluestem-Native system. Peak standing crop of Old World bluestem averaged 4640 kg ha(-1) but did not differ between the cultivars 'WW-Iron Master' and 'WW-Spar' (P = 0.16). Individual steer gain was higher in the Native system during the Winter (P < 0.01) and Early Native (P = 0.03) management periods, but was greater in the Old World bluestem-Native system when steers were grazing Old World bluestem in June and July (P < 0.001). Over the entire season, steers in the Native system gained 13.5 kg head(-1) more than steers in the Old World bluestem-Native system. Total livestock production was greater in the Old World bluestem-Native system (77 versus 47 kg ha(-1), P < 0.01). Relative economic returns between the 2 systems were dependent on the marginal value of livestock gain and the relative costs of production for the 2 types of pasture. With average costs for native pasture of 17 ha(-1) and for Old World bluestem pasture of 62.10 ha(-1), the Native system was often more profitable, even though livestock production per ha was much higher with the Old World bluestem-Native system. Lower costs for native pasture and high values of livestock gain favored the Native system.
Dietary structural types of polygastric herbivores at different environments and seasons
Authors: Pelliza A. , Willems P. , Manacorda M. ,   Society for Range Management
Published: March 2016

A classification of dietary structural types that represents different arrangements of forage classes is proposed. It may be especially useful for interpreting and comparing herbivore diets from different environments. As an example, a data set with the botanical composition of 55 pooled fecal samples determined by microhistological analysis was analyzed. These samples came from 4 species of range herbivores (cattle, sheep, goat, and guanaco -Lama guanicoe-), from 9 different environments of Northern Patagonia (Argentina) during 3 seasons. Based on plant characteristics related with the capacity of the animals to eat and digest each plant and with the occasional or permanent presence of them in the vegetation, the information was grouped into 5 forage classes: woody plants, perennial grasses, annual grasses, grasslikes, and forbs. A principal component analysis of the grouped data was conducted. The graphic representations evidenced the gradual changes in the structure of the data. Later, working over the subspace defined by the 3 first principal component axes, a hierarchical classification was performed that resulted in 9 dietary structural types. These types represented variation that resulted from the interaction of pasture differences, species of herbivore and season. This concept is an abstraction developed from the experience, to extend its utility beyond the particular cases.
Alkaloids as anti-quality factors in plants on western U.S. rangelands
Authors: Pfister J. A. , Panter K. E. , Gardner D. R. ,   Society for Range Management
Published: March 2016

Alkaloids constitute the largest class of plant secondary compounds, occurring in 20 to 30% of perennial herbaceous species in North America. Alkaloid-containing plants are of interest, first because alkaloids often have pronounced physiological reactions when ingested by livestock, and second because alkaloids have distinctive taste characteristics. Thus, alkaloids may kill, injure, or reduce productivity of livestock, and have the potential to directly or indirectly alter diet selection. We review 7 major categories of toxic alkaloids, including pyrrolizidine (e.g., Senecio), quinolizidine (e.g., Lupinus), indolizidine (e.g., Astragalus), diterpenoid (e.g., Delphinium), piperidine (e.g., Conium), pyridine (e.g., Nicotiana), and steroidal (Veratrum-type) alkaloids. Clinically, effects on animal production vary from minimal feed refusal to abortion, birth defects, wasting diseases, agalactia, and death. There are marked species differences in reactions to alkaloids. This has been attributed to rumen metabolism, alkaloid absorption, metabolism, excretion or directly related to their affinity to target tissues such as binding at receptor sites. In spite of alkaloids reputed bitter taste to livestock, some alkaloid-containing plant genera (e.g., Delphinium, Veratrum, Astragalus, Oxytropis, and Lupinus) are often readily ingested by livestock. Management schemes to prevent losses are usually based on recognizing the particular toxic plant, knowing the mechanism of toxicity, and understanding the temporal dynamics of plant alkaloid concentration and consumption by livestock. Once these aforementioned aspects are understood, losses may be reduced by maintaining optimal forage conditions, adjusting grazing pressure and timing of grazing, aversive conditioning, strategic supplementation, changing livestock species, and herbicidal control.
Anti-quality factors associated with alkaloids in eastern temperate pasture
Authors: Thompson F. N. , Stuedemann J. A. , Hill N. S. ,   Society for Range Management
Published: March 2016

The greatest anti-quality associated with eastern temperature pasture grasses is the result of ergot alkaloids found in endophyte-infected (Neotyphodium ceonophialum) tall fescue (Festuca arundinacea Schreb.) The relationship between the grass and the endophyte is mutualistic with greater persistence and herbage mass as a result of the endophyte. Ergot alkaloids reduce growth rate, lactation, and reproduction in livestock. Significant effects are the result of elevated body temperature and reduced peripheral blood flow such that necrosis may result. Perturbations also occur in a variety of body systems. Planting new pastures with seed containing a "non-toxic" endophyte appears to be a potential solution. Ergotism results from the ingestion of the scelerotia of Claviceps purpurea containing ergot alkaloids found on seed heads. Ergotism resembles the effects of endophyte-infected tall fescue. Endophyte-infected perennial ryegrass (Lolium perenne L.) contains ergot and lotirem alkaloids that result in reduced growth and tremors. Reed canarygrass (Phalaris Anundinacba L.) contains tryptamine, hordenine and gramine alkaloids that reduce growth. Annual ryegrass (Lolium multiplorum L. may contain galls with cornetoxins which result in neurological signs.
Endophytic fungi in Canada wild rye in natural grasslands
Authors: Vinton M. A. , Kathol E. S. , Vogel K. P. ,   Society for Range Management
Published: March 2016

Some grasses harbor endophytic fungi living in intercellular spaces in the leaves, stems and reproductive organs. The fungi can dramatically affect the physiology and ecology of plants. For example, fungi may produce toxins that deter herbivores and they may alter the water status of the plant to increase drought tolerance. The distribution of fungal infection in natural plant populations is unknown for many host species. We investigated the occurrence of endophytic fungi in Elymus canadensis L. (Canada wild rye) from 13 remnant prairie sites in the midwest and 23 sites in the southern Great Plains. Collections of plant tissue came from Nebraska, Kansas, Minnesota, Iowa, Missouri, Illinois, Oklahoma, and Texas. All midwest plants were grown in a common garden site in eastern Nebraska. Seeds collected from Oklahoma and Texas accessions were planted in the greenhouse. At least 3 tillers from 2 plants of each accession were screened for endophytes, using light microscopy. The endophytic fungus was found in seed of all accessions and in plants from all but 4 accessions. The functional significance of the fungus is unclear, but it may affect plants by enhancing productivity or deterring herbivores. The widespread occurrence of endophytic fungi in natural populations of E. canadensis suggests that the plant-fungal association may be long-standing and important in the evolution and success of this native prairie species.
Characterization and habitat preferences by white-tailed deer in Mexico
Authors: Bello J. , Gallina S. , Equihua M. ,   Society for Range Management
Published: March 2016

We analyzed the habitat preferences of white-tailed deer in a 1,000 ha area in an arid region of northeastern Mexico where drinking water is abundant throughout the year (via 33 water troughs). Seven habitat types in the study area were identified and characterized. Within each habitat, feeding, searching, and bedding activities were evaluated during the reproduction, postreproduction and fawning seasons of the annual deer cycle. The Acacia-Celtis habitat provided the greatest amount of hiding and thermal cover and edible food. The Prosopis habitat also provided significant hiding and thermal cover. Hilaria and Opuntia were the most open habitats. Habitat preferences, evaluated by radiotracking 14 deer over a period of 2 years, varied between sexes and years (P << 0.00001), but not among seasons (P > 0.05). Male deer preferred open habitats, while females preferred more densely covered ones. Males and females avoided Prosopis during 1996. Both sexes distributed the 3 activities more evenly during 1996 than during 1995. In 1995, females preferred Flourensia and Acacia-Celtis habitats for all activities, and during 1996 males preferred Hilaria and Leucophyllum. Between year changes in precipitation could explain the observed variability: during 1995 rainfall was 136 mm, as compared to 276 mm in 1996. Requirements for cover increased markedly in 1995 due to high predation and extremely dry conditions. Overall, our study shows that under good weather conditions, habitat preferences are best explained by variables associated with food availability, while thermal cover is more important under harsh weather conditions, even when drinking water is abundant.
Journal of Range Management, Volume 54, Number 5 (September 2001)
Authors:   Society for Range Management
Published: March 2016

Complete digitized issue.
Point sampling for leaf area index in sagebrush steppe communities
Authors: Clark P. E. , Seyfried M. S. ,   Society for Range Management
Published: March 2016

Although point sampling has been used for more than 30 years to quantify leaf area index (LAI), this field technique has not been rigorously evaluated in sagebrush steppe plant communities. Leaf area index estimates obtained using different sampling pin inclinations or combinations of pin inclinations were evaluated in Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle and Young), low sagebrush (Artemisia arbuscula Nutt.), and mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana [Rydb.] Beetle) communities within the Reynolds Creek Experimental Watershed near Boise, Ida. Leaf area index values determined by clipping and processing green foliage through a leaf area meter were used as evaluation standards. Pins inclined at 13 degrees from the horizontal, used alone or in combination with pins of 52 degrees and/or 90 degrees inclinations, performed poorly for estimating LAI in the Wyoming big sagebrush and low sagebrush communities. Estimating total LAI with either the combination of 52 degrees and 90 degrees angle pins or with 52 degrees or 90 degrees pins alone explained at least 96% of the variability in LAI standard values from the Wyoming big sagebrush and mountain big sagebrush communities. Using 52 degrees angle pins alone produced model fits similar to those obtained when the combination of 52 degrees and 90 degrees angle pins were used to estimate shrub, graminoid, and forb LAI across all 3 communities (P > 0.1). Collecting point data using 52 degrees angle pins often provided better or similar model fits with LAI standards compared to other pin angles but using 90 degrees angle pins offers a better compromise between practicality, efficiency, and accuracy.
Principles and practices for managing rangeland invasive plants
Authors: Masters R. A. , Sheley R. L. ,   Society for Range Management
Published: March 2016

Invasive plants reduce the capacity of ecosystems to provide goods and services required by society, alter ecological processes, and can displace desirable species. They can reduce wildlife habitat quality, riparian area integrity, rangeland economic value, and enterprise net returns. The invasion process is regulated by characteristics of the invading plant and the community being invaded. The presence and spread of invasive plants is often symptomatic of underlying management problems that must be corrected before acceptable, long-term rangeland improvement can be achieved. Disturbance appears to be important early in the invasion process because it creates vacant niches that alien plants can occupy. Control of invasive plants may only open niches for establishment of other undesirable plants unless desirable plants are present to fill the vacated niches. In many instances, rangelands have deteriorated to the point that desirable species are either not present, or in such low abundance that plant community recovery is slow or will not occur without revegetation after invasive plants are controlled. Integrated weed management employs the planned, sequential use of multiple tactics (e.g. chemical, biological, cultural, and mechanical control measures) to improve ecosystem function (energy flow and nutrient cycling) and maintain invasive plant damage below economic levels, and emphasizes managing rangeland ecosystem functions to meet objectives rather than emphasizing a particular weed or control method. Sustainable, integrated invasive plant management strategies require assessing plant impacts, understanding and managing the processes influencing invasion, knowledge of invasive plant biology and ecology, and are based on ecological principles. Invasive plant management programs must be compatible with and integrated into overall rangeland resource management objectives and plans. Because of the complexity of managing invasive plants, it is imperative that relevant ecological and economic information be synthesized into user-friendly decision support systems.
Resilience of prickly burnet to management in east Mediterranean rangelands
Authors: Perevolotsky A. , Ne'Eman G. , Yonatan R. ,   Society for Range Management
Published: March 2016

Large areas of rangelands in the east Mediterranean Basin are dominated by dense cover of the unpalatable, dwarf shrub prickly burnet (Sarcopoterium spinosum (L.) Spach.). This study examined the effectiveness of various shrub control treatments (mechanical removal, chemical/2,4-D control, prescribed burning), combined with NPK fertilization, to reduce shrub cover and encourage the growth of palatable herbaceous vegetation. Chemical control was the most effective treatment, reducing prickly burnet cover to 40% of the initial level 2 years after treatment. Mechanical removal maintained shrub cover at 60% of the initial level, whereas the effect of fire was not detectable after 2 years. Annual and perennial herbaceous vegetation cover was negatively correlated with shrub cover. Fertilization had no effect on the cover of the vegetative components, but increased biomass on the herbaceous patches by 25-240%, depending on the treatment. Our results demonstrate the exceptionally high resilience of prickly burnet growing on chalk substrate to disturbance or attempted eradication, thus rendering most of the tested management options highly ineffective. Effective improvement of rangeland dominated by prickly burnet requires, most probably, a combined treatment including removal of mature shrubs, suppressing their recovery, and stimulating the competing grass component.
Grassland birds associated with agricultural riparian practices in southwestern Wisconsin
Authors: Renfrew R. B. , Ribic C. A. ,   Society for Range Management
Published: March 2016

Rotational grazing has been proposed as a Best Management Practice (BMP) for minimizing runoff in Wisconsin agricultural riparian areas. The influence of this land management practice on grassland birds has not been evaluated in relation to more traditional agricultural land management systems in Midwestern riparian areas. This study compared the grassland bird community in riparian areas in Wisconsin that were rotationally grazed to 2 common land use practices along streams in Wisconsin: continuously grazed pastures and rowcrop fields with 10-m-wide ungrazed buffer strips located along the stream. We calculated total number of birds, the Berger-Parker Index of Dominance, and number of birds ha(-1) for each site. Vegetation variables used were height-density, litter depth, and percent bare ground. Bird species richness, species dominance, and density did not differ among land use types. In contrast, grassland bird species of management concern [Savannah Sparrow (Passerculus sandwichensis Gmelin), Eastern Meadowlark (Sturnella magna L.), and Bobolink (Dolichonyx oryzivorus L.)] were found on continuous and rotational pastures but very rarely or never occurred on buffer strips. Contrary to previous research, however, rotationally grazed pastures did not support more of these species than continuously grazed pastures. Bird density was related to vegetation structure, with higher densities found on sites with deeper litter. Within the pasture land use types, there were no consistent differences between species richness and density near the stream (10 m) and away (10 m).
Community characteristics of old-growth western juniper woodlands
Authors: Waichler W. S. , Miller R. F. , Doescher P. S. ,   Society for Range Management
Published: March 2016

While considerable attention has been given to the areal expansion of juniper (Juniperus sp.) in the western United States, the presence and ecological significance of old-growth juniper communities has gone largely unnoted. Increased recognition of these communities has prompted questions about how to recognize old-growth, community structure, ecological importance, and appropriate management. As an initial analysis of old-growth western juniper woodlands (Juniperus occidentalis Hook var. occidentalis Vasek) in central Oregon, this study investigated old-growth community structure on eolian-sand derived soils. These woodlands represent the most extensive old-growth western juniper woodlands throughout its range. Nine study plots were established at 7 sites. Within each plot, densities and physical attributes of all live trees and large standing and fallen woody detritus were recorded. Additional measurements for live trees included canopy cover, apparent age class (pre- or postsettlement), and a sampling of tree ages. Aging of trees older than 250 years was complicated by extensive heartwood rot. Shrub density and cover were measured by species. Understory cover was measured by species and functional type. Bare ground, rock, juniper litter, other litter, moss, and cryptogamic crust cover were also measured. Plant cover ranged from 11 to 33% for trees, 0 to 10% for shrubs, 3 to 12% for perennial grasses, 1 to 2% for forbs, and from 0 to 0.1% for annual grasses. The woodlands contained at least 80 trees ha(-1) aged over 200 years. Correlations between tree parameters and understory structure and composition were generally poor. Differences in plant composition among these stands was primarily attributed to elevation, slope, and percent sand content. Structural characteristics that distinguished old-growth stands from younger stands included tree growth form, presence of standing and dead large woody debris, lichen on dead branches, and a relatively open canopy. Results provide a preliminary basis for identifying old-growth Juniperus occidentalis stands, as a prelude to the development of management plans and further research into the functional characteristics of the systems. A definition of old-growth juniper woodlands is presented.
Quantifying suitable habitat of the threatened western prairie fringed orchid
Authors: Wolken P. M. , Sieg C. H. , Williams S. E. ,   Society for Range Management
Published: March 2016

Land managers need accurate and quick techniques to identify suitable habitat of species of interest. For species protected by federal or state laws, identification of suitable habitat is critical for developing a conservation strategy that includes reestablishing populations and altering management to address this need. In this research, we quantified vegetative and edaphic habitat of the western prairie fringed orchid (Platanthera praeclara Sheviak and Bowles), a federally listed threatened plant. Lowlands (swales) that supported orchids in our southeastern North Dakota study area were characterized as having a higher soil moisture content within the top 10 cm, when compared to swales devoid of orchids. The vegetative composition of orchid-supporting swales reflected this higher moisture content. These data were then used in developing a logistic regression model to differentiate suitable habitat. The model correctly classified 84% of 38 swales as either orchid-supporting or non-orchid-supporting using 4 variables: percent canopy cover of Baltic rush (Juncus balticus Willd.) and hedge-nettle (Stachys palustris L.), soluble soil magnesium and August surface soil moisture. Land managers can use this model to rapidly assess the suitability of a site in this ecoregion for the orchid. By collecting data on the cover of just Baltic rush, which would take about 45 minutes, and entering it in the equation, a land manager could correctly classify 66% of the orchid swales as either suitable or unsuitable as orchid habitat. This approach, because it incorporates quantitative data and allows managers to rapidly and accurately identify suitable habitats, shows promise for other plant species.
Nutritional dynamics of 7 northern Great Basin grasses
Authors: Ganskopp D. , Bohnert D. ,   Society for Range Management
Published: March 2016

Land, livestock, and wildlife managers need to understand the nutritional dynamics of forages to sustain adequate growth and reproduction of their animals and/or assure equitable payment for forages. Despite a long history of livestock grazing in the northern Great Basin, seasonal and annual nutritional dynamics of many of the region's prominent grasses have not been described. We addressed this issue via monthly sampling of 7 cool-season grasses at 6 sites during 1992, a drier than average year having 86% of mean precipitation, and 1993, when above average precipitation (167% of average) occurred. With high yields predicted in 1993 (1,257 kg ha(-1)), the period of adequate forage quality [crude protein (CP) greater than or equal to 7.5%] was 83 days. In addition grasses did not respond to 97 mm of July-August rain with renewed growth. During 1992, a growing season beginning with less than average moisture, grasses responded to midsummer (49 mm) and fall (69 mm) rains by maintaining greater than 7.5% CP for 185 days. A diversity of grasses expanded the period of adequate forage quality especially during the lower than average moisture year. Giant wildrye (Elymus cinereus Scribn. Merr.), a deeply rooted grass, supported high quality forage until mid August, but did not respond to late-season moisture. In contrast, shallow rooted grasses like bottlebrush squirreltail (Sitanion hystrix (Nutt.) Smith), Sandberg's bluegrass (Poa sandbergii Vasey), and the winter-annual cheatgrass (Bromus tectorum L.) responded to summer or fall moisture with herbage ranging from 10 to 16% CP, thereby supplying high quality late-season forage. With most precipitation occurring in the northern Great Basin during colder months, livestock or habitat managers can, with a fair degree of certainty, predict yields from their pastures before turnout. With abundant moisture, managers will see the rapid deterioration of forage quality that occurs when grasses advance through their reproductive stages of phenology and generate a wealth of reproductive stems. The quandary arrives, however, when moisture accumulations are less than optimum. Fewer reproductive tillers develop, and our results show that timely precipitation may elevate desirable nutrient characteristics and expand the duration of adequate livestock/wildlife nutrition in the region. More long-term research is needed to decipher the mechanisms governing growth and development of rangeland grasses and to assess risks of various stocking alternatives when managers face uncertain yield and forage quality issues.
Tracked vehicle impacts to vegetation structure and soil erodibility
Authors: Grantham W. P. , Redente E. F. , Bagley C. F. ,   Society for Range Management
Published: March 2016

There has been increasing concern that training on military lands results in excessive soil erosion, ecosystem degradation, and loss of sustainable training resources. Vegetation structure has been shown to play a role in soil surface stabilization by reducing shear stress caused by wind force. A study at the Idaho Army National Guard training facility at Orchard Training Area (OTA), Ida. assessed the effect of simulated M1A2 Abrams battletank maneuvers on grassland plant canopies and soil erodibility. The point-intercept method was used to estimate vertical vegetation structure before and after tracking. A portable wind tunnel was used to measure threshold wind speeds (TWS) associated with different numbers of tank passes and soil mass removed by wind. Results indicated that significant damage occurred to vertical vegetation structure as the number of passes increased. Threshold wind speed, an indicator of soil surface stability, significantly decreased with tracking and eroded soil mass significantly increased. Positive correlations existed between vegetation parameters and threshold wind speed. Soil loss was negatively correlated with vegetation parameters. Results indicated that the decrease of vertical vegetation structure led to a decrease in threshold wind speed. This decrease in threshold wind speed was the result of reduced soil surface protection by vegetation. Decreased surface protection also resulted in increased soil loss. Results from this work confirmed that vegetation plays a major role in reducing shear stress on the soil surface. Predictions for soil loss at Orchard Training Area resulting from the number of M1A2 passes are made using linear models. A critical tracking threshold of 4 passes was estimated based upon model output and average local wind speeds for Orchard Training Area.
Climatic influences on recruitment of 3 subspecies of Artemisia tridentata
Authors: Maier A. M. , Perryman B. L. , Olson R. A. ,   Society for Range Management
Published: March 2016

Previous research suggested that big sagebrush (Artemisia tridentata Nutt.) recruitment occurs in pulses consistent with favorable climatic conditions. In 1997, 75 stem sections were collected from 9 stands of each of the 3 subspecies of big sagebrush in Wyoming along elevation and climatic gradients. Annual growth rings were used to identify the year plants were established. Large cohorts of Wyoming big sagebrush (A. tridentata ssp. wyomingensis Beetle and Young) appeared in 1982, 1981, 1964, 1961, and 1955. Basin big sagebrush (A. tridentata ssp. tridentata Beetle and Johnson) cohorts flourished in 1991, 1986, 1985, 1982, and 1977. Mountain big sagebrush (A. tridentata ssp. vaseyana [Rydb.] Beetle) cohorts prospered in 1985, 1982, 1981, 1979, and 1974. Mean monthly precipitation and temperature records were compared to years with high and low recruitment using logistic regression models at 3 geographic scales (single-stand, regional, statewide). Wyoming big sagebrush recruitment was greatest in years with above-average December and January precipitation occurring after the first growing season (r2 = 0.10, 0.04, P < 0.05). Basin big sagebrush recruitment was most successful in years with above-average March, May, and June precipitation during the first growing season (r2 = 0.06, 0.09, 0.18, P < 0.05). Mountain big sagebrush recruitment was greatest in years with below-average February, April, and May precipitation after the first growing season (r2 = 0.03, 0.04, 0.04, P < 0.05). While variable precipitation patterns appear to contribute significantly to recruitment of big sagebrush, responses among the 3 major subspecies were quite variable. More complex models need to be developed to foster our understanding of the mechanisms affecting big sagebrush establishment.
Long-term plant community development as influenced by revegetation techniques
Authors: Newman G. J. , Redente E. F. ,   Society for Range Management
Published: March 2016

A revegetation techniques study was initiated during the fall of 1976 in northwestern Colorado in a disturbed sagebrush (Artemisia tridentata Nutt.) community. The study included 2 irrigation treatments, three seed mixtures, 2 seeding techniques, and 2 fertilization treatments. Short-term results were published and conclusions were made regarding the initial success of each treatment. The objective of the current study was to determine the effects of each treatment on plant community production, species composition, and species diversity after 20 years of plant community development. Among irrigated plots, the native seed mixture produced greater aboveground biomass compared to an introduced mixture and a mixture of both native and introduced species (combination seed mixture). The native seed mixture also resulted in greater total species richness than the introduced mixture when averaging over all other treatments. Altered seeding rate ratios among life forms as well as altered seeding methods (drill versus broadcast seeding) did not significantly alter plant community development after 20 years. However, a single application of nitrogen and phosphorus significantly increased grass production on plots seeded to the combination seed mixture. All revegetation plots have remained grass-dominated. However, shrub biomass was greater in the native and combination mixtures than in the introduced mixture under initial irrigated conditions in part due to successful establishment and growth of four-wing saltbush (Atriplex canescens Pursh Nutt.). Thus, the seed mixtures evaluated in this study have resulted in distinctly different plant communities and demonstrate that such initial treatments can influence long-term plant community development on severely disturbed rangelands. Broadcast seeding a native seed mixture that has been irrigated for 2 growing seasons without fertilization appears to be an effective long-term combination of cultural revegetation practices.
Mesquite and grass interference with establishing redberry juniper seedlings
Authors: Teague W. R. , Dowhower S. L. , Whisenant S. G. ,   Society for Range Management
Published: March 2016

Excessive cover of juniper (Juniperus pinchotii Sudw.) reduces forage production, interferes with livestock management, and diminishes the watershed and wildlife habitat values of rangelands. We studied whether juniper seedlings were differentially suppressed in the presence of different grass species, and to what extent established mesquite (Prosopis glandulosa Torr.) trees facilitated or competed with establishing juniper seedlings. Seedlings growing with any of the grasses (RGR = 0.23 to 0.43 cm cm(-1)) grew significantly less than those with no grass competition (RGR = 0.72 cm cm(-1))(P < 0.01). Juniper seedlings grew significantly less in the presence of buffalograss (Buchloe dactyloides (Nutt.) Engelm.) (RGR = 0.23 cm cm(-1) than with either sideoats grama (Bouteloua curtipendula (Michx.) Torr.) (RGR = 0.43 cm cm(-1)) or tobosagrass (Hilaria mutica [Buckl.] Benth.) (RGR = 0.43 cm cm(-1))(P < 0.01). In contrast, juniper seedlings grew larger under intact canopies of mesquite (RGR = 0.99 cm cm(-1)) than in open grassland (RGR = 0.65 cm cm(-1))(P < 0.05) due in part to the greater nutrient availability (P < 0.05) under mesquite canopies. Juniper growing in sub-canopy positions with mesquite trees removed grew less (RGR = 0.84 cm cm(-1)) than those growing under mesquite canopies with root competition (RGR = 0.99 cm cm(-1))(P < 0.05). Juniper growing under intact mesquite canopies but without mesquite root competition, grew no better or worse (RGR = 0.93 cm cm(-1)) than those with mesquite root competition (RGR = 0.99 cm cm(-1))(P > 0.05), indicating that mesquite root competition with juniper is probably inconsequential. Since junipers grow mainly in fall, winter and spring when mesquite trees are dormant and leafless, the lack of competition may largely be due to these 2 species using resources at different times of the year. Greater nutrient availability beneath mesquite canopies, reduction of summer temperatures, and temporal separation of resource use clearly benefit juniper seedlings growing in the presence of mesquite. Managing for a vigorous grass component with low densities and cover of mesquite is the best way to limit the rate of invasion by juniper.
Drought and grazing: IV. Blue grama and western wheatgrass
Authors: Eneboe E. J. , Sowell B. F. , Heitschmidt R. K. ,   Society for Range Management
Published: March 2016

An understanding of the impacts of grazing during and following drought on rangeland ecosystems is critical for developing effective drought management strategies. This study was designed to examine the effects of drought and grazing on blue grama [Bouteloua gracilis (H.B.K) Lag. ex Griffiths] and western wheatgrass [Pascopyrum smithii Rydb. (Love)] tiller growth dynamics. Research was conducted from 1993 to 1996 at the Fort Keogh Livestock and Range Research Laboratory located near Miles City, Mont. An automated rainout shelter was used during 1994 to impose a severe late spring to early fall (May to October) drought on 6 of twelve, 5- x 10-m non-weighing lysimeters. Twice replicated grazing treatments were: 1) grazed both the year of (1994) and the year after (1995) drought; 2) grazed the year of and rested the year after drought; and 3) no grazing either year. Drought had minimal impact on tiller relative growth rates of plants grazed twice, although it reduced (P less than or equal to 0.01) rates of axillary tiller emergence for blue grama (79%) and western wheatgrass (91%), respectively. Defoliation periodically increased relative growth rates (P less than or equal to 0.05) and tiller emergence (P less than or equal to 0.01) of both species. Neither drought nor grazing affected tiller densities or tiller replacement rates of either species nor did they affect productivity of blue grama. Drought, however, reduced (P less than or equal to 0.01) productivity of western wheatgrass 50% in 1994 whereas grazing reduced productivity (P less than or equal to 0.01) by 46% in 1994 and 69% in 1995. Moderate stocking levels (40-50% utilization) during and after drought did not adversely affect the sustainability of these dominant native grasses.
Classifying federal public land grazing permittees
Authors: Gentner B. J. , Tanaka J. A. ,   Society for Range Management
Published: March 2016

This study identifies the characteristics and attitudes of public land ranchers. Data from a random survey of 2,000 U.S. Forest Service and Bureau of Land Management grazing permittees (53.5% response rate) were cluster analyzed and 8 distinct groups of ranchers were identified. Each cluster differed with respect to why they were in ranching and how they would respond to public land policy changes related to grazing fees, grazing reductions, and changes in grazing season. Profit motivation for being in ranching was found to be a relatively low objective for all 8 types of ranchers.