Your search for keyword(s) "shrub" resulted in 21 record(s).

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Title: Impacts of fire and invasive species on desert soil ecology: Journal: Rangeland Ecology & Management; Authors: E. B. Allen, R. J. Steers, and S. J. Dickens; Date: 2011; Summary: This is a literature review of 92 published scientific articles covering the effects of fire and annual weeds on soil chemistry, microbiology and conservation. ...; Agrovoc Control Words: Desert soils, Fire Ecology, Invasive species; View more details about this article

Title: Canopy growth and density of Wyoming Big Sagebrush sown with cool-season perennial grasses: Journal: Arid Land Research and Management; Authors: A. L. Hild, G. E. Schuman, L. E. Vicklund, and M. I. Williams; Date: 2006; Summary: The importance of long-term data collection to studies involving plant community dynamics and the apparent increased influence of grass seeding rates on sagebrush growth as the vegetation matures was examined in this subsequent study. Initial research began in 1998 on a reclamation site at the Belle Ayr Coal Mine in northeastern Wyoming (44Â° 17'ï¿½ N; 105Â° 30' W) and examined the establishment of Wyoming big sagebrush when sown with three perennial cool-season native grasses. The results are reported in the initial study which can be found in the RSIS ...; Agrovoc Control Words: Mining, Sagebrush, Reclamation; View more details about this article

Title: Initial beaked hazel growth responses following protection from ungulate browsing: Journal: Journal of Range Management; Authors: J. N. Best, E. W. Bork, and N. L. Cool; Date: 2003; Summary: The authors investigated the growth response of beaked hazel (Corylus cornuta) at four sites within Elk Island National Park, with and without grazing, at the plant and community levels, to determine the impact of ungulate browsing on this species. Plant responses to protection from grazing depended on the site. The number of leaves and length of twigs increased at two sites, while the number of twigs, but not twig length, increased at one site; no difference were detected at the fourth site. This suggests that other factors, specific to each site, such as environmental ...; Agrovoc Control Words: Riparian zones, Rangelands, Wildlife; View more details about this article

Title: Nonequilibrium dynamics of sedge meadows grazed by cattle in southern Wisconsin: Journal: Plant Ecology; Authors: B. Middleton; Date: 2002; Summary: The effects of cattle grazing and exclusion on the long-term structural characteristics of sedge meadows in the Lodi Wildlife Area, WI (43Ëš 19â€™ N; 89Ëš 37â€™ W) were examined to test the equilibrium theory from 1977-1997. Four sites (reference-very lightly grazed, lightly grazed, moderately to heavily grazed and recovering-no grazing since 1973) were examined. Four environmental factors including recovery time (years since grazing), tussock height, frequency of hoof prints, and water depth at base of tussock (if present) were calculated and measured. ...; Agrovoc Control Words: Riparian zones, Grazing, Wildlife; View more details about this article

Title: Gender-related differences of shrubs in stands of Atriplex canescens with different histories of grazing by cattle: Journal: Journal of the Arid Environment; Authors: A. F. Cibils, D. M. Swift, and R. H. Hart; Date: 2000; Summary: In this study, Cibils et al. determined Atriplex canescens sizes, ages and sex ratios in pastures that were summer grazed, winter grazed, or ungrazed for 20 years. Ungrazed shrubs were the largest and oldest, and shrubs in winter grazed pastures were the smallest and youngest, most likely because shrub use was greatest during the winter. Grazed shrub communities had fewer female plants, that were smaller and younger than female plants inside exclosures. Females may be more susceptible to grazing damage or may be more likely to be grazed than male plants. Based on these results, the authors ...; Agrovoc Control Words: Riparian zones, Rangelands, Wildlife; View more details about this article

Title: Seasonal cattle management in 3 to 5 year old bitterbrush stands: Journal: Journal of Range Management; Authors: D. Ganskopp, T. Svejcar, F. Taylor, J. Farstvedt, and K. Paintner; Date: 1999; Summary: After a 3-year study, Ganskopp et al. determined the cumulative effects of grazing on young bitterbrush (Purshia tridentata) plants for combinations of winter wildlife use and early- or late-season cattle grazing. Utilization of bitterbrush was higher during late season cattle grazing than early season and was related to the start date of grazing and the digestibility of other available forages. Winter wildlife use somewhat reduced the differences between the two cattle grazing treatments but late season cattle use still reduced height, diameter, and volume of bitterbrus ...; Agrovoc Control Words: Riparian zones, Rangelands, Wildlife; View more details about this article

Title: Seasonal grazing impact on cryptogamic crusts in a cold desert ecosystem: Journal: Journal of Range Management; Authors: K. L. Memmott, V. J. Anderson, and S. B. Monsen; Date: 1998; Summary: Memmott et al. measured cryptogamic crust cover after two years of spring, summer or winter grazing, to determine how grazing in different seasons effects this fragile vegetative cover. Grazing in all seasons reduced lichen cover, however, moss cover was only reduced in spring and summer grazed pastures. Total cryptogamic crust cover varied among grazing treatments; it was lowest in the summer grazed pasture, intermediate in the spring grazed pasture, and greatest in the winter grazed pasture. The authors suggest that frozen soils reduce the hoof impact caused by cattle grazing in winter an ...; Agrovoc Control Words: Riparian zones, Rangelands, Wildlife; View more details about this article

Title: Shrub densities in relation to fire, livestock grazing, and precipitation in an Arizona desert grassland: Journal: Southwestern Naturalist; Authors: C. E. Bock, and J. H. Bock; Date: 1997; Summary: Baccharis pteronioides and Haplopappus tenuisectus are two shrubs that are increasing in the desert grasslands of Arizona, however, the cause of their increase is not known. In this study, Bock and Bock attempt to relate changes in populations of these shrubs to regional climate changes, fire frequency, and cattle use. Baccharis pteronioides density was not greatly affected by grazing or fire. Cattle use slightly reduced shrub density and regrowth following fire, but this shrub was greatly affected by variations in winter precipitation; increasing when winter precipitation is high and decre ...; Agrovoc Control Words: Riparian zones, Rangelands, Wildlife; View more details about this article

Title: Small-mammal regulation of vegetation structure in a temperate savanna: Journal: Ecology; Authors: J. F. Weltzin, S. Archer, and R. K. Heitschmidt; Date: 1997; Summary: Weltzin et al. measured the characteristics of honey mesquite populations on and off two prairie dog colonies to determine if prairie dogs, and other species associated with their colonies, limit the encroachment of this shrub on grasslands. On prairie dog colonies, honey mesquite seed and pod disappearance was greater, emergence and survival of seedlings was lower, and the survival of sapling sized trees was also lower. The density of mesquite plants was greater on prairie dog colonies, but due to continued defoliation, all plants were small and short unlike the few, large, older shrubs tha ...; Agrovoc Control Words: Riparian zones, Rangelands, Wildlife; View more details about this article

Title: Influence of rodent predation on antelope bitterbrush seedlings: Journal: Journal of Range Management; Authors: C. D. Clements, and J. A. Young; Date: 1996; Summary: Rodent predation on Lassen antelope bitterbrush (Purshia tridentata) seedlings was studied in burned and unburned antelope bitterbrush communities in California in 1993. Rodent densities were estimated at 15/ha in the burned habitat, and 14/ha in the unburned habitat, using the minimum known number alive method. Ord's kangaroo rat (Dipodomys ordii) was the species captured the most (n=13), followed by deer mice (Peromyscus maniculatus) (n=8), and Great Basin pocket mice (Perognathus parvus) (n=7). Rodents si ...; Agrovoc Control Words: Riparian zones, Rangelands, Wildlife; View more details about this article

Title: Sites, mowing, 2,4-D, and seasons affect bitterbrush twig morphology: Journal: Journal of Range Management; Authors: V. M. Kituku, J. Powell, and R. A. Olson; Date: 1994; Summary: Antelope bitterbrush (Purshia tridentata) plants,at three topographic areas (valley bottom, upper slope, mountain terrace), in south-central Wyoming were mowed in May to 2-3-cm stubble height or treated with 2,4-D to suppress surrounding herbaceous vegetation. The area is grazed by cattle in summer and occasionally by mule deer and elk in winter. Generally, mowing did not decrease twig length on the less productive sites and greatly increased it on more productive sites. Sites, shrub management practices, and season do affect bitterbrush twig morphology, but habitat manag ...; Agrovoc Control Words: Riparian zones, Rangelands, Wildlife; View more details about this article

Title: Effects of grazing and drought on population dynamics of salt desert shrub species on the Desert Experimental Range, Utah: Journal: Journal of Arid Environments; Authors: J. C. Chambers, and B. E. Norton; Date: 1993; Summary: Chambers and Norton examined natality, mortality, and population turnover of dominant salt desert shrub species under different seasons (winter vs. spring) and intensities (light vs. heavy) of grazing, during a drought period on the Desert Experimental Range in southwestern Utah. Plant responses varied by species, grazing intensity and season of use. The negative effects of grazing were exacerbated by drought conditions, however, in some instances grazing enhanced plant survival and reproduction. In general, spring grazing and heavy grazing had the greatest negative effects while light wint ...; Agrovoc Control Words: Riparian zones, Rangelands, Wildlife; View more details about this article

Title: Quantitative effects of grazing on vegetation and soils over a global range of environments: Journal: Ecological Monographs; Authors: D. G. Milchunas, and W. K. Lauenroth; Date: 1993; Summary: Multiple regression analyses were performed on worldwide 236-site data set compiled from studies that compared species composition, aboveground net primary production (ANPP), root biomass, and soil nutrients of grazed vs. protected, ungrazed sites. The authors' objective was to quantitatively assess factors relating to differential sensitivities of ecosystems to grazing by large herbivores. Changes in species composition with grazing were primarily a function of ANPP and the evolutionary history of grazing of the site, with level of consumption third in importance. Changes in species compos ...; Agrovoc Control Words: Riparian zones, Rangelands, Wildlife; View more details about this article

Title: Range animal diet composition in southcentral Wyoming: Journal: Journal of Range Management; Authors: K. R. Ngugi, J. Powell, F. C. Hinds, and R. A. Olson; Date: 1992; Summary: The significance of shrubs in the diets of cattle, deer, elk, pronghorn and sheep grazing two different shrub communities (a big sagebrush community and a mountain shrubland) were studied in southcentral Wyoming for one year. Dung samples for all ungulates were collected in spring, summer and fall. Diet composition (to genus) was determined from fecal samples. ...; Agrovoc Control Words: Grazing, Rangelands, Ungulates; View more details about this article

Title: Interactions of grazing and plant protection on basin big sagebrush (Artemisia tridentata ssp. tridentata) seedling survival: Journal: Journal of Range Management; Authors: M. K. Owens, and B. E. Norton; Date: 1992; Summary: Owens and Norton examined the role of grazing and protective plant cover on basin big sagebrush (Artemisia tridentata spp. tridentata) seedling survival on crested wheatgrass (Agropyron desertorum) seeded pastures after short duration, high intensity sheep or cattle grazing. During the grazing period, survival of seedlings was lower and grazing reduced survival of unsheltered seedlings. Sheltered seedlings had greater seedling survival in general but during the end of season drought, survival of sheltered seedlings in grazed past ...; Agrovoc Control Words: Riparian zones, Rangelands, Wildlife; View more details about this article

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