Dissertations / Theses on the topic 'Rangelands'
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Ruyle, George. "Arizona's Rangelands." College of Agriculture, University of Arizona (Tucson, AZ), 1992. http://hdl.handle.net/10150/295709.
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Sprinkle, Jim. "Crossbreeding Systems for Arizona Rangelands." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2000. http://hdl.handle.net/10150/144720.
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Fotouo, Makouate Helene. "Dispersal strategies in communal versus privately-owned rangeland in Namaqualand, South Africa." Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-01282009-155013.
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Despain, Del W., Phil R. Ogden, George B. Ruyle, and E. Lamar Smith. "Some Methods For Monitoring Rangelands and Other Natural Area Vegetation." College of Agriculture, University of Arizona (Tucson, AZ), 1997. http://hdl.handle.net/10150/304566.
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Despain, Del W., Phil R. Ogden, George B. Ruyle, and E. Lamar Smith. "Some Methods for Monitoring Rangelands and Other Natural Area Vegetation." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/311743.
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Abolhassani, Leili [Verfasser], and Gerhard [Akademischer Betreuer] Oesten. "Rangeland management in Iran : : a socio-economic analysis and case study of Semnan Rangelands = Rangeland-Management im Iran - eine sozio-ökonomische Analyse und Fallstudie Semnan." Freiburg : Universität, 2011. http://d-nb.info/112346037X/34.
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Gadd, Michelle Erin. "Ecology and conservation of elephants in African rangelands /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.
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FLOYD, DONALD WINTERS. "THE POLICY OF EXPERIMENTAL STEWARDSHIP ON PUBLIC RANGELANDS." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/183950.
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Between July and September, 1985, 70 ranchers, environmentalists and agency officials participating in three chartered Experimental Stewardship Program (ESP) areas were interviewed. Committee records and agency documents were also examined. As a result of the field work three conclusions were reached: (1) conflicts over grazing decisions have been significantly reduced by the stewardship process, (2) available data is insufficient to support conclusions about changes in the ecological status of the plant communities within the stewardship areas and (3) the annual economic value of rangeland recreation exceeds all other rangeland outputs on all three areas studied.
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Cook, Seth. "Carbon Sequestration on Utah Rangelands: A Landowner Perspective." DigitalCommons@USU, 2012. https://digitalcommons.usu.edu/etd/1421.
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Rangelands have significant potential to sequester carbon and contribute to the mitigation of climate change. This research aimed at better understanding the beliefs, attitudes, and perceptions of Utah rangeland owners concerning carbon sequestration and climate change, examining their current grazing management practices in relation to soil carbon sequestration, and exploring factors influencing their likelihood of participating in future programs. Data were collected through interviews of Utah rangeland owners and range management professionals and a statewide rangeland owner survey. About two-thirds of respondents thought the climate had been changing over the last 30 years, were aware of carbon sequestration, and viewed it positively. Forty-one percent considered it an important management objective. Having positive attitudes was associated with having “biocentric” environmental value and believing climate change and its anthropogenic nature. Respondents valued the potential ecological benefits of carbon sequestration, indicated a preference for educational programs over financial incentives, and preferred working with private agricultural organizations over non-profit or government entities on carbon management. Thirty-seven percent of respondents reported likely to participate in a carbon sequestration program. Higher likelihood was associated with dependence on livestock production, considering carbon sequestration an important management objective, being interested in learning more about it, and placing high importance on the economic and climate benefits of participating in relevant programs. These results suggest potential challenges for developing technically sound and socially acceptable policies and programs for promoting carbon sequestration on private rangelands. Rangeland owners’ attitudes towards carbon sequestration may play a strong role in their participation in future programs. Although education and outreach are considered important, innovative strategies are needed to communicate the concept and processes of carbon sequestration with rangeland owners without politicizing the issue. One approach is to tailor education and outreach messages to focus on the ecological benefits of carbon sequestration. Efforts are also needed to enhance the cooperation between private agricultural organizations and government agencies to promote carbon management on private rangelands. Instead of developing new programs, funneling resources to improve the carbon sequestration potential of existing conservation programs and attract wider participation among rangeland owners may be another cost effective policy strategy.
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O'Brien, William Eugene. "Participation and indigenous knowledge in development for African pastoralists." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-10222009-125038/.
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Savage, Shannon Lea. "Vegetation dynamics in Yellowstone's Northern Range 1985 - 1999 /." Thesis, Montana State University, 2005. http://etd.lib.montana.edu/etd/2005/savage/SavageS1205.pdf.
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Blumenfeld, Hana Devorah. "Quantifying rangeland health indicators using runoff and sediment from rainfall simulator experiments." Thesis, The University of Arizona, 2002. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_etd_hy0041_m_sip1_w.pdf&type=application/pdf.
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Ruyle, George B., Lamar Smith, Jim Maynard, Steve Barker, Dave Stewart, Walt Meyer, Bill Couloudon, and Stephen Williams. "Principles of Obtaining and Interpreting Utilization Data on Rangelands." College of Agriculture, University of Arizona (Tucson, AZ), 2016. http://hdl.handle.net/10150/625541.
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14 pp. / Originally published: 2007A primary expression of stocking levels on rangeland vegetation is utilization defined as the proportion or degree of current years forage production that is consumed or destroyed by animals (including insects). Utilization may refer either to a single plant species, a group of species, or the vegetation as a whole. Utilization is an important factor in influencing changes in the soil, water, animal, and vegetation resources. The impact of a specific intensity of use on a plant species is highly variable depending on past and present use, period of use, duration of use, inter-specific competition, weather, availability of soil moisture for regrowth, and how these factors interact. Utilization data can be used as a guideline for moving livestock within an allotment with due consideration to season, weather conditions and the availability of forage and water in pastures scheduled for use during the same grazing season. In combination with actual use and climatic data, utilization measurements on key areas and utilization pattern mapping are useful for estimating proper stocking levels under current management. Utilization studies are helpful in identifying key and problem areas, and in identifying range improvements needed to improve livestock distribution. Reviewed 10/2016. Originally published 5/2007.
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Howery, Larry D., Fred D. Provenza, and George B. Ruyle. "How Do Domestic Herbivores Select Nutritious Diets on Rangelands?" College of Agriculture, University of Arizona (Tucson, AZ), 2016. http://hdl.handle.net/10150/625544.
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8 pp. / Originally published: 1998Animal learning has been shown to play a major role in the development of diet selection by domestic herbivores. Dr. Frederick Provenza and his associates at Utah State University have conducted a series of studies over the past 30 years to learn how physiological and behavioral mechanisms govern diet selection. In this paper, we synthesize several key diet selection concepts presented in 4 articles (i.e., Provenza et al. 1992; Provenza 1995, 1996, 1997). Reviewed 12/2014; originally published 05/1998.
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Howery, Larry D., and Frederick Provenza. "How Do Domestic Herbivores Select Nutritious Diets on Rangelands?" College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/144716.
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8 pp.Animal learning has been shown to play a major role in the development of diet selection by domestic herbivores. Dr. Frederick Provenza and his associates at Utah State University have conducted a series of experiments over the past 15 years to learn how physiological and behavioral mechanisms govern diet selection. This publication synthesizes several key diet selection concepts presented in four recent articles.
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Ruyle, George B., Lamar Smith, Jim Maynard, Steve Barker, Dave Stewart, Walt Meyer, Bill Couloudon, and Stephen Williams. "Principles of Obtaining and Interpreting Utilization Data on Rangelands." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2007. http://hdl.handle.net/10150/146918.
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14 pp.A primary expression of stocking levels on rangeland vegetation is utilization defined as the proportion or degree of current years forage production that is consumed or destroyed by animals (including insects). Utilization may refer either to a single plant species, a group of species, or the vegetation as a whole. Utilization is an important factor in influencing changes in the soil, water, animal, and vegetation resources. The impact of a specific intensity of use on a plant species is highly variable depending on past and present use, period of use, duration of use, inter-specific competition, weather, availability of soil moisture for regrowth, and how these factors interact. Utilization data can be used as a guideline for moving livestock within an allotment with due consideration to season, weather conditions and the availability of forage and water in pastures scheduled for use during the same grazing season. In combination with actual use and climatic data, utilization measurements on key areas and utilization pattern mapping are useful for estimating proper stocking levels under current management. Utilization studies are helpful in identifying key and problem areas, and in identifying range improvements needed to improve livestock distribution.
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Ferreira, Gustavo. "An evolutionary approach to farming decision making on extensive rangelands." Thesis, University of Edinburgh, 1998. http://hdl.handle.net/1842/28012.
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In more than 25 years, a simplistic model of farm decision making has been used to support agricultural policy, research and extension without considering socio-economic and environmental sustainability. The basic assumptions of policy development were based on an "average farmer" and the marginal value of money completely ignoring the marginal social value. This research claims the need of a more holistic "model" of decision making at farm level, where i) behaviour diversity is recognised in farmers' populations and ii) the dynamic and evolutionary interrelationships between the farm, the farmer, the family and trusted people as a unit of resource allocation, are considered. The objectives of this work are to: i) improve the understanding of the decision making process at farm level ii) develop decision concepts for research and extension agencies and policy makers and iii) demonstrate that rural people's knowledge plays an important role in development. A selective review of the main approaches and of descriptive models used to analyse decision making, a survey and a case study analysis is undertaken in order to develop: i) a conceptual background for classifying decision making units into different behavioural Types and ii) a general 'model' of the structure of the farm decision making unit's "natural" decision support system actually used by farmers. Multivariate techniques were used to establish and validate the classification. Several implications for policy makers, information generators and data transmitters underlying the study were identified.
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Powell, Neil. "Co-management in non-equilibrium systems : cases from Namibian rangelands /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1998. http://epsilon.slu.se/avh/1998/91-576-5486-7.pdf.
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Howery, Larry D., and Peter C. Sundt. "Using Repeat Color Photography as a Tool to Monitor Rangelands." College of Agriculture, University of Arizona (Tucson, AZ), 2016. http://hdl.handle.net/10150/625547.
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6 pp. / Originally published: 1998This article provides an introduction to repeat color photography and explains how it can be used as an important part of a comprehensive rangeland monitoring program. Reviewed 12/2014. Originally published 05/1998.
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Howery, Larry D., and Peter Sundt. "Using Repeat Color Photography as a Tool to Monitor Rangelands." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/146934.
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6 pp.It is important to show people that what you say is true when your critics weren't around 10-15 years ago to see the changes you have seen. A series of photographs taken at the same spot through the years can vividly demonstrate change on the range. This article provides an introduction to repeat color photography and explains how it can be used as an important part of a comprehensive rangeland monitoring program.
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Osei-Amaning, E. "Management of Vitellaria paradoxa in Guinea savanna rangelands in Ghana." Thesis, Bangor University, 1996. https://research.bangor.ac.uk/portal/en/theses/management-of-vitellaria-paradoxa-in-guinea-savanna-rangelands-in-ghana(8ebb01bb-84ff-4365-9f49-1a881953db43).html.
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From 1993-1994, a study of Vitellaria paradoxa was carried out. This study involved an in-depth review of biological and ecological information on Vitellatia throughout its range. Stand studies and an analysis of the climate in relation to fire risk. There were also experimental investigations of germination and pollination. All field studies were at the site of the Cocoa Research Institute outstation at Bole. Stand characteristics of Vitellaria (>10 cm dbh) at the 68 kM2 plot of the Cocoa Research Institute's Sheanut Research Station, Bole were examined in two strata distinguished on the basis of distance from the nearest village: >3.0 km and <3.0 km. Regeneration (<10 cm dbh) was assessed and recorded for height, root collar diameter and mode of regeneration. Analysis of variance indicated higher stocking of individuals > 10 cm dbh further from villages but significantly more Vitellaria trees >10 m tall close to villages. Suckers accounted for > 86% of regenerating individuals, and more than 90% of regenerating plants were < 50 cm high. Analysis of climatic data indicated a mean drought index (1990-1994) of 514 ± 61 points. However, the fire danger index never reached an extreme value. The germination response of depulped, cracked and intact seeds of Vitellaria sown under- and outside the canopy of mature Vitellatia trees (> 30 cm dbh), showed a significant association between germination and seed treatment: a higher proportion of depulped than intact seeds germinated. Open pollinated flowers, gave significantly lower fruit set than hand-pollinated flowers. There was no difference, however, in the amount of fruit set achieved with pollen from sources 50 m, 500 m and 1000 m away or from flowers of two different style lengths. It is concluded that fires are adversely affecting the population structure and natural regeneration of stands at Bole, and that low fruit set in Vitellaria is due at least in part, to low vector activity. Suggestions are made for future research on the species.
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Fowers, Beth. "Ecologically-Based Manipulation Practices for Managing Bromus tectorum-infested Rangelands." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/1019.
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Cheatgrass (Bromus tectorum) is an invasive annual grass common in several semiarid plant communities in the western U.S. B. tectorum presence increases fire frequency and size, reducing species diversity, and leading to annual species-dominated systems with inconsistent livestock forage potential and degraded wildlife habitat value. Most efforts to manage B. tectorum-dominated rangelands have focused on controlling the plant itself rather than addressing the causes of vegetation change. An alternative approach, ecologically-based invasive plant management (EBIPM), identifies treatments that can alter factors associated with the causes of succession, leading to a more desirable vegetation state. This study utilized the EBIPM framework to design a large-scale demonstration project, which implemented a series of manipulation treatments (mowing, prescribed fire, imazapic herbicide, and seeding with perennial species) to suppress B. tectorum and promote desirable species. The treatments were implemented at two semiarid shrubland sites in northwestern Utah. Treatments were evaluated by measuring resident vegetation cover, density, aboveground biomass, and litter and soil seed banks. Herbicide was most effective in reducing B. tectorum cover, density, and biomass, while fire was effective in reducing seed density in the litter seed bank. Treatment interactions were rarely significant; however, by combining fire and herbicide, increased B. tectorum control was achieved. Seedlings of seeded perennial grasses emerged in all treatments; however, establishment by the end of the first growing season was greatest in treatments involving fire. The results of this study indicate that using a decision-making framework to select a series of treatments that alter the causes of succession can improve the management of B. tectroum-dominated rangelands.
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Johnson, Haley Mae Ann. "Impacts of Prescribed Fire and Grazing on Northern Great Plains Rangelands." Thesis, North Dakota State University, 2018. https://hdl.handle.net/10365/29007.
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Prescribed burning was utilized as a management tool on grasslands of the Northern Great Plains. We analyzed the use of fire to manipulate encroaching and unpalatable western snowberry (Symphoricarpos occidentalis), to promote browsing and improve nutritive quality. Fire was successful at altering the nutrient quality of western snowberry and selectivity of grazing livestock from plant specific to patch specific. Additionally, we evaluated the difference between burn season and frequency on plant community dynamics of an ungrazed tallgrass prairie invaded by Kentucky bluegrass (Poa pratensis). Fire promoted native forb and grass species, stressing that native species are well adapted to the historical disturbance. Our research emphasizes the need for restored fire regimes in the Northern Great Plains to benefit numerous aspects of prairie ecosystem function, stability, services, and productivity.U.S. Forest Service
Central Grasslands Research and Extension Center
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Uys, Roger Gregory. "Patterns of plant diversity and their management across South African Rangelands." Doctoral thesis, University of Cape Town, 2006. http://hdl.handle.net/11427/6200.
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Forbs dominate southern Africa's rangeland plant diversity, but have been ignored in favour of grasses that are important for livestock production. To facilitate better conservation management I examined the interaction between patterns of diversity, forb recruitment and disturbance effects across the mesic to semi-arid rangelands east of the escarpment in southern Africa. Results were compared to a well studied North American tallgrass prairie, Konza. Sampled between 1 m2 and 1000 m2 across 25 sites, species and family richness increased with mean annual precipitation up to â2000 m a.s.l., above which cooler temperatures accounted for a decline. Forb functional types ranged from persistent (long-lived, resprouters) in the fire-prone mesic rangelands to more recruiting (short-lived, reseeders) taxa in the drought-prone semi-arid areas. Mesic rangelands should therefore tolerate frequent, low intensity defoliation, and semiarid floras be better suited to infrequent intense disturbances. Seedling recruitment matched richness patterns, primarily increasing with precipitation. Recruitment was highest in the fire treatment at the three mesic sites, but proportionately higher in the animal digging and drought treatments at the three semi-arid sites. Seedling composition differed from the adult sward, suggesting that some species may not recolonise transformed lands. Despite predictions of the Milchunas et al. (1988) and Olff and Ritchie (1998) grazing models, exclusion of large mammalian grazers from 40 m x 40 m plots did not appear to impact forb diversity. Instead, grazing effects sampled in 100 x 1m' quadrats per treatment, across ten sites, were overridden by the mesic to semi-arid gradient along which the sites were orientated. Species richness declined under heavy communal cattle grazing along fence-line contrasts at two mesic sites, with soft-leaved monocot (orbs being replaced by short-lived divot weeds not found inside the adjacent lightly grazed nature reserves. Marked differences in the diversity and disturbance responses of tallgrass prairie and southern African rangelands suggest that management strategies cannot be extrapolated from similar ecosystems around the world.
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Lien, Aaron Matthew, and Aaron Matthew Lien. "Incentives for Ecosystem Services on Rangelands: Institutional Design and Stakeholder Attitudes." Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/624284.
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Payments for ecosystem services (PES), or conservation incentives, are an increasingly popular approach to encouraging natural resources conservation on private lands. The goal of PES approaches is to motivate conservation by private landowners that would not otherwise take place by providing an economic incentive. To achieve this goal, incentive programs must be available to landowners who can provide the desired services; supportive policy structures must be in place; landowners must be willing to participate as sellers of ecosystem services; and the program itself must have an institutional structure that effectively regulates the production, sale, and maintenance of targeted ecosystem services. This dissertation uses a combination of case study and comparative research methods to develop new knowledge and tools for assessing each of these necessary conditions for success. The potential development of an incentive program to conserve habitat for endangered jaguars in southern Arizona and southwestern New Mexico is used as a case study to understand the attitudes of ranchers toward participation in PES programs and related policies and regulations. Results show that ranchers have strong intrinsic conservation motivations unrelated to economic incentives, coupled with significant concerns about the impacts of government regulations that could accompany participation in a PES program. Comparative research of the institutional structures of existing PES programs is carried out using the Institutional Analysis and Development framework. Focusing on water quality trading, one of the most common types of PES program, a classification system for PES program institutional arrangements is developed and the utility of the classification system for analyzing institutional diversity is demonstrated. Together, the case study and comparative research provide a means of linking empirical assessment of PES governance models with the preferences of targeted participants, increasing the likelihood of successful conservation outcomes.
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Schad, Brandon J. "Reproductive ecology of resident and translocated bobwhites on south Florida rangelands." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0024663.
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York, Elisabeth C. "Rancher Perceptions of Ecosystem Services from Rangelands of the Intermountain West." DigitalCommons@USU, 2017. https://digitalcommons.usu.edu/etd/6859.
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Rangelands within the Great Basin are responsible for the provision of multiple resources that humans depend on for a variety of reasons. Ranchers in this region are dependent on public lands to remain economically viable in their cattle operations. As a majority of land in this region is publically owned, there are varying interests at play in what should and could be the focus of management. Ranchers are charged with implementing strategies aimed at conserving these landscapes and their motivations for what to manage may significantly influence resource provision from Intermountain West ecosystem.
In this study, I sought to understand what resources ranchers manage and why ranchers manage for certain resources. I also sought to understand operational characteristics which allow or inhibit them from managing for a suite of resources. My study population was ranchers throughout the Intermountain West who depend on public lands to graze their cattle. I utilized interviews as well as mail-in surveys to broadly understand what ranchers value about rangelands. From both qualitative and quantitative data, I found that ranchers make management decisions to encourage productivity, maintain a ranching legacy and remain autonomous in their operation. Managing to encourage these three ideals could ensure that their operations remain viable for their family in the future. I also found that based on size of operation, how active ranchers are on their operation, and how income dependent they are on their operation contribute to managing for more and a certain type of resource.
Overall, this research was designed to encourage management for a suite of resources on rangeland landscapes. Ranchers seem to manage most highly for resources directly beneficial to their operation. By educating and incentivizing ranchers to manage more broadly for resources that benefit a broader public on public lands which we all hold claim to, resilience of both human communities as well as the ecosystem itself will be enhanced.
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Gokbulak, Ferhat. "Seed Dispersal by Livestock: A Revegetation Application for Improving Degraded Rangelands." DigitalCommons@USU, 1998. https://digitalcommons.usu.edu/etd/6564.
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A series of experiments was conducted to: 1) investigate how feeding cattle with different amounts of different-sized seeds affects seed passage rate through the digestive tract, and the germinability of passed seeds; 2) examine how the location of seeds in dungpats of different thicknesses influences seedling emergence , development, and survival in cattle dungpats; and 3) characterize seedling emergence in naturally and artificially deposited cattle dungpats . Three perennial , cool-season grasses, bluebunch wheatgrass [Psuedoroegneria spicata (Pursh) A. Love], Sandberg bluegrass (Poa secunda Presl.), and 'Hycrest' crested wheatgrass [Agropyron desertorum (Fisch. ex Link) X A. cristatum (L.) Gaert.], were used as representative revegetation species for the Intermountain West region.
When cattle were fed 60,000, 30,000, 15,000, and 7,500 seeds of bluebunch wheatgrass and Sandberg bluegrass, the recovery of passed seeds for both species declined as seed feeding levels decreased from 60,000 to 7,500 seeds per animal and as time after seed ingestion increased from 1 to 4 days. Sandberg bluegrass seeds had greater germinability than bluebunch wheatgrass seeds at all seed feeding levels and collection dates.
In complementary greenhouse studies, artificially prepared cattle dungpats (20 cm diameter) with different thicknesses (1, 2, and 4 cm) were placed on a sandy loam soil (initially at field capacity) in large plastic containers. Pre-germinated seeds of blue bunch wheatgrass, Sandberg bluegrass, and/or Hycrest crested wheatgrass were planted separately in the center and periphery of dungpats at heights (from bottom of dungpats) of 0.5 cm for 1-cm-thick dungpats, 0.5 and 1.5 cm for 2-cm-thick dungpats , and 0.5, 2.0, and 3.5 cm for 4-cm -thick dungpats. Half of the dungpat treatments received no supplemental water while the other half received additional water simulating a wet spring . After 60 days, seedling emergence, development , and survival for all species were greatest at the 0.5 cm planting height , regardless of dungpat thickness , and greatest in 1 cm-thick dungpats , regardless of planting height. Seedling emergence , development , and survival were greatest for Hycrest crested wheatgrass, followed by bluebunch wheatgrass and Sandberg bluegrass.
In a field study, cattle dung containing passed seeds of blue bunch wheatgrass, Hycrest crested wheatgrass, and Sandberg bluegrass was formed into artificial dungpats (2 kg in mass) with thicknesses of 1, 2, and 4 cm, and respective diameters of 40, 28, and 20 cm, and deposited on bare soil. Cattle also deposited natural dungpats varying in mass, thickness, and diameter. Seedling emergence for all species decreased as artificial dungpat thickness increased from 1 to 4 cm, and was lowest in natural dungpats. Seedling emergence for all dungpat types was greatest for Hycrest crested wheatgrass, followed by Sandberg bluegrass and bluebunch wheatgrass.
These studies indicate that: 1) cattle should be fed about 60,000 seeds ( of these grass species) per animal to pass sufficient germinable seed to establish at least one seedling in a dungpat; and 2) seedling emergence, development, and survival in cattle dungpats are greatly influenced by plant species (seeds) ingested, thickness of dungpats, seed location in dungpats, and moisture content of the soil underlying dungpats.
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Ratsele, Clement Ratsele. "Long-term ecological effects of rangeland burning, grazing and browsing on vegetation and organic matter dynamics." Thesis, University of Fort Hare, 2013. http://hdl.handle.net/10353/d1006844.
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To proffer a sustainable solution to ecological degradation in rangeland ecosystems as a consequence of fire, grazing and browsing, an understanding of rangeland ecological processes is vital. Due to the complexity of ecological processes and their interrelationships, it is usually difficult or expensive to directly measure status of ecological processes. Therefore, biological and physical characteristics are often used to indicate the functionality of ecological processes and site integrity. Long-term effects of fire, grazing and browsing on characteristics of the vegetation and organic matter and their subsequent effects on selected rangelands ecosystem ecological processes was conducted at Honeydale section of the University of Fort Hare farm in the Eastern Cape Province of South Africa and Matopos Research Station in Zimbabwe. In this study, attributes of biotic community integrity (species richness, composition and diversity), soil stability (basal cover, standing dead grass biomass, tuft to tuft distance, tufts diameter, canopy distance and stem to stem distance), productivity and plant vigour (grass yield, total canopy volume, plant height, canopy height, canopy diameter, main stem diameter, sprouts diameter and number of sprouts) and hydrologic function and nutrient cycling (grass litter biomass, soil organic carbon and microbial biomass carbon) were used to estimate long-term effects of burning, grazing and browsing by goats on the functionality of ecological processes in the rangeland ecosystem. Burning did not have differential effect on grass species richness (P>0.05), woody species diversity as well as compositional percentage for D.eriatha, C.plurinodis, S.fimbriatus, A.karro and E.rigida. Burning increased decreasers and increaser II species proportions and reduced (P ≤ 0.05) grass yield, total canopy volume, tree height, canopy height main stem diameter and sprouts diameter. Long-term burning, grazing, and goats browsing had differential effects on site stability. The effects on basal cover, tuft to tuft distance, tufts diameter, canopy distance and basal distance as a consequence of long-term burning, grazing, and goats browsing were not significantly different, whereas the effects on standing dead grass biomass as a result of long-term burning frequencies were significantly different. Long-term effects of burning followed by ten-year period of fire exclusion had significantly different effects on tuft-tuft distance but did not have statistically different effects on tufts diameter, canopy distance and basal distance. Long-term burning grazing and browsing had significantly different effects on attributes of hydrologic functions and nutrient cycling in the rangeland ecosystem (grass litter biomass, SOC and BMC). Long-term effects of burning followed by ten-year period of fire exclusion had significantly different effects on grass litter biomass, and SOC. Through their effect on vegetation and organic matter characteristics, burning, grazing and browsing could influence functionality of selected rangeland ecological processes such as biological community integrity, productivity and plant vigour, site stability, hydrologic function and nutrient cycling.
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Keren, Ilai Naftaly. "Thermal balance model for cattle grazing winter range." Thesis, Montana State University, 2005. http://etd.lib.montana.edu/etd/2005/keren/KerenI0805.pdf.
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Dube, Sikhalazo. "A model for adaptive livestock management on semi-arid rangelands in Texas." Diss., Texas A&M University, 2003. http://hdl.handle.net/1969.1/3975.
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A stochastic, compartmental Model for Adaptive Livestock Management (MALM) was developed for cow-calf enterprise for Rolling Plains of Texas from an existing model, Simple Ecological Sustainability Simulator (SESS). The model simulates forage and animal production. It runs on a monthly time step. Two stocking strategies, flexible and fixed, were evaluated at seven stocking levels for effects on forage and animal production, range condition, and net ranch income. Evaluation data were obtained from published and unpublished data from Texas A&M Agricultural Experimental Station at Vernon for Throckmorton. The model adequately simulated forage and animal production. Light fixed stocking rates and flexible stocking strategies resulted in cows of median body condition score (BCS) 5, compared to low BCS of 4 under moderate fixed stocking rate, and BCS of 3 under heavy fixed stocking. BCS declined from autumn to early spring and peaked in summer. Cows under light fixed stocking rates and under flexible stocking were heavier (460 kg) compared to those under heavy fixed stocking (439 kg). Replacement rates were lower under light stocking (22 %), compared to flexible (37 %) and heavy stocking (56 %). Calf crops were all above the reported 90 % expected for bred heifers because of the replacement policy. Flexible stocking strategy resulted in higher net income ($19.62 ha-1), compared to fixed light ($5.93 ha-1) or fixed heavy ($-17.35 ha-1) stocking strategies. Coefficient of variation (CV) in net income was highest under heavy stocking (90%) compared to light stocking (60%) and flexible stocking (50%). Maximum net income was obtained between 0.05 AUM·ha-1 and 0.13 AUM·ha-1 when fixed stocking strategy was used but when flexible stocking strategy was used maximum net income was obtained between 0.1 AUM·ha-1 and 0.17 AUM·ha-1. Range condition rapidly declined under fixed heavy stocking, increased under fixed and light flexible stocking, and remained constant under moderate flexible stocking. Heavy fixed stocking decreased range condition rapidly over a 20-year period. MALM was an effective tool to demonstrate effects of different management strategies. The model can function as a strategic or a tactical decision aid. It is concluded that there is potential for this model to assist managers in improving the sustainability of agriculture.
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Gregory, Lucas Frank. "Water budgets and cave recharge on juniper rangelands in the Edwards Plateau." Texas A&M University, 2005. http://hdl.handle.net/1969.1/3791.
Full textAbstract:
Increasing demand for water supplies in semi-arid regions, such as San Antonio,
has sparked an interest in potential recharge management through brush control. Two
shallow caves under woody plant cover in northern Bexar County, Texas were chosen as
study sites where a detailed water budget would be developed. The Headquarters Cave
site measures natural rainfall and cave recharge while the Bunny Hole site is
instrumented to measure throughfall, stemflow, surface runoff, and cave recharge. Large
scale rainfall simulation was used at Bunny Hole to apply water directly above the cave
footprint allowing us to determine how recharge differs between natural and simulated
rainfall events. Under natural conditions, Headquarters Cave recharged 15.05% of the
annual rainfall while Bunny Hole received 4.28%. Natural canopy throughfall measured
59.96% of the water budget; stemflow accounted for 0.48% and canopy interception was
39.56%; no surface runoff was measured. Rainfall simulations conducted at Bunny Hole
resulted in an average of 74.5% throughfall, 5.3% stemflow, 20.2% canopy interception,
2.8% surface runoff, and 6.9% cave recharge; simulation intensities were typically
higher than natural event intensities. General water budgets across the Edwards Plateau have concluded that evapotranspiration represents 65% of total annual rainfall while
percolation and storage accounts for 30% and the remaining 5% is runoff. These studies
have been focused on broad water budget parameters while this study looks at more
detailed components. No other study to date has been able to combine throughfall,
stemflow, surface runoff, and vertical recharge monitoring to quantify the water budget
in the Edwards Plateau; these parameters are instrumental in determining a detailed
water budget in juniper rangelands. Results from this study illustrate the significance of
all aspects of the water budget and are the first to yield a firm measurement of actual
upland recharge.
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Hobbs, Trevor J., and n/a. "Herbage production modelling and assessment in the arid rangelands of Central Australia." University of Canberra. Applied Science, 1994. http://erl.canberra.edu.au./public/adt-AUC20060725.143830.
Full textAbstract:
The management and sustainable use of Central Australian rangelands for
livestock production and conservation requires improved knowledge of the
temporal and spatial distribution of primary production in this region. To provide
such information, this thesis investigated methods that could rapidly and efficiently
estimate regional herbage biomass production in these arid landscapes. Two
different approaches were examined, using (1) ground-based or (2) satellite-based
data sources.
Soil moisture and herbage growth data were collected over several growth
seasons and five landscape types in Central Australia, and the data used to develop
a model of soil moisture balance and herbage production for the region. The
model has few parameters and only requires inputs of rainfall and potential
evaporation to predict daily soil moisture and plant growth. Moisture loss in the
0-500 mm soil profile was modelled using a negative exponential function that
depends on available soil moisture and is driven by potential evaporation. The
growth of herbage, whilst soil moisture is above wilting point, is a linear function
of actual evapotranspiration, with the decay of plant material represented by a
logistic curve through time.
Soil moisture, herbage biomass and species composition assessments made
at hectare and square kilometre scales at four locations within Central Australia
were examined to determine if a small sample area could be used to accurately
describe the soil and plant conditions at a landscape scale. Moisture levels of the
0-200 and 0-500 mm soil profiles from nine samples were analysed for the
beginning and conclusion of a growth season, whilst herbage biomass and species
composition from 50 samples were compared at the end of the growth season.
Results suggest that mean soil moisture levels determined in a 1 ha area are
comparable with mean values in the surrounding 1 km2 area. Herbage biomass
and species richness for a square kilometre can be assessed at a hectare site for
some landscape types, but a larger sampling area (> 1 ha) is recommended for
most rangeland assessments.
Satellite data (NOAA-11) were examined for their potential application in
assessing primary productivity in Central Australia. Several image correction
techniques were tested to minimise the adverse effects of atmospheric
contamination and illumination. Two measures of atmospheric moisture: (1)
radiosonde data and (2) temperature differences between bands 4 and 5 of the
NOAA satellite (split-window) were used to explain variations in NOAA-11
normalised difference vegetation index (NDVI) on inert desert sites. The splitwindow
approach provided the best single factor relationship (r2=0.63) and, when
combined with scattering angle (illumination) effects, up to 81% of the variation
in NDVI data could be explained.
Field measurements of herbage biomass were correlated with four growth
indices derived from NOAA-11 NDVI data. The influence of preflight and sensor
degradation calibrations of Bands 1 and 2, and atmospheric correction techniques
were also tested. Correlations between temporal sums of NDVI and herbage
biomass data were relatively poor (r2<0.42) and unsuitable for herbage
assessment in Central Australia. However, correlations between atmospherically corrected
and background-adjusted maximum NDVI data and observed herbage
biomass were strong (r2=0.91), that will allow primary production in the arid
rangelands of Central Australia to be assessed rapidly and efficiently using
remotely-sensed information.
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Waltee, Dean James. "Seasonal dispersal tendencies of sylvan deer mice (peromyscus maniculatus) with montana rangelands." The University of Montana, 2008. http://etd.lib.umt.edu/theses/available/etd-12162007-133018/.
Full textAbstract:
We examined seasonal dispersal habits of sylvan deer mice (Peromyscus maniculatus) within two Montana rangeland types over a three - year period. The rangeland types included a grassland and shrub-steppe habitat. Within the state of Montana, both habitat types commonly contain peridomestic settings due to the widespread influence of the ranching industry. These peridomestic environments are where most reported human cases of Hantavirus Pulmonary Syndrome (HPS) originate. During the study, we trapped each site twice a month in two week intervals through all weather conditions and a temperature range from -36.7 to + 40.0 °C. We accumulated 85,200 trap nights of effort and captured 6,185 individual deer mice a total of 22,654 times. We documented a total of 980 dispersing individuals over three years. Our results demonstrated no significant seasonal differences in the number of dispersing individuals. However, we did find a positive correlation between number of dispersing individuals and number of individuals captured at both sites. We also found that adult males tended to disperse more often during the spring compared to other seasons.
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Bilbao, Joshua Vicente. "Predicting feeding site selection of mule deer on foothill and mountain rangelands." Thesis, Montana State University, 2008. http://etd.lib.montana.edu/etd/2008/bilbao/BilbaoJ1208.pdf.
Full textAbstract:
Determining areas on the landscape selected by mule deer (Odocoileus hemionus) for foraging and the characteristics of selected feeding sites is a crucial step in managing mule deer and its habitat. Mule deer populations in much of western North America have been declining since the early 1990\'s, making management of mule deer increasingly difficult. Limited research has examined the characteristics of mule deer habitat that influence feeding site selection in foothill and mountain rangeland habitats during the winter and spring. The purpose of the study was to develop and validate models that incorporate the effects of important habitat variables that influence feeding sites chosen by mule deer in the winter and spring, including aspect, distance to forested cover, distance to hiding cover, distance to agricultural fields, distance to improved roads, distance to ranch roads, elevation, previous cattle grazing, and slope. Data collected in northwestern Wyoming between the summer of 1999 and spring of 2001 were used for model development, and data collected between summer 2001 and spring 2003 were used for temporal validation. Additionally, data collected in west-central Montana between summer 2001 and spring 2003 were used for temporospatial validation. Logistic regression was used to develop models for the winter, spring, and winter-spring seasons. Akaike\'s Information Criterion was used to determine the best models for each season. Models were validated on both a temporal and temporospatial scale. Six habitat variables (distance to improved roads, distance to ranch roads, distance to security cover, aspect, slope, and previous summer\'s cattle grazing) were included in model development after collinearity tests. Four models had a model sensitivity > or equal to 75% in both temporal and temporospatial validation. These models can be used to identify preferred mule deer feeding sites and assess potential impacts of land management practices on mule deer foraging habitat.
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Littlefield, Joanne. "Monitoring Rangelands in Arizona: Method Assesses Changes Over Time for Better Management." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2007. http://hdl.handle.net/10150/622130.
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Dufek, Nickolas Alois. "An Assessment of Integrated Weed Management Strategies for Purple Threeawn-Dominated Rangelands." Thesis, North Dakota State University, 2013. https://hdl.handle.net/10365/26635.
Full textAbstract:
Purple threeawn (Aristida purpurea Nutt.) is a native bunch grass that is avoided by grazers. It is capable of dominating old cropland and overgrazed pastures, limiting livestock carrying capacity, and degrading wildlife habitat. Traditional management tools have had little impact on threeawn dominance in semiarid regions of the west. Our objectives were to: 1) assess fire and nitrogen treatment effects on threeawn forage quality at various phenological stages to test their potential as pretreatments in a grazing strategy and 2) examine a threeawn-dominated plant community?s response to prescribed fire, nitrogen addition, and clipping. Fire improved threeawn forage quality with greater improvements in early phenological stages. Nitrogen had little effect on forage quality. Fire and nitrogen reduced threeawn while increasing cool season grasses. Light and moderate clipping following fire did not improve the efficacy of fire. Fire appears to an effective preliminary treatment to improve the chance of herbivory.
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Magomani, Matimba Israel. "The effect of fire management on chemical and physical properties of rangelands." Thesis, University of Fort Hare, 2017. http://hdl.handle.net/10353/6191.
Full textAbstract:
The use of fire in rangeland has become standard practice for decades; however, there is no shared understanding of how fire affects soil properties. The exact relationship between fire and soil properties is still yet to be understood. The differences in fire frequency, fire intensity, fire severity, the period between fire and sampling resulted in contradictory results amongst studies. A long-term trial at the University of Fort Hare provides a valuable experimental layout for fire research. The trial was established in 1980 with the aim of investigating the effect of burning frequency on vegetation species composition and biomass production. The objective of this study was however to determine the effect of fire management on soil chemical and physical properties under the long-term burning experiment. The treatments of the study site were: no burn (K), annual (B1), biennial (B2), triennial (B3), quadrennial (B4) and sexennial (B6) burns. A line intercept sampling technique was used to collect the soil samples from the surface (0 to 75 mm) for both chemical and physical analysis. All Burning treatments significantly (p < 0.05) increased the bulk density (Db), soil pH, total cations, Magnesium (Mg) and Calcium (Ca), but reduced the soil porosity and exchangeable acidity when compared to the control. Hydraulic conductivity (Ks), water conducting macroporosity (WCM) and total nitrogen were reduced under more frequent burning treatments (B1, B2), as compared to less frequent burning treatments (B3, B4, B6). The aggregate stability showed an opposite trend. Total organic carbon (TOC) was reduced only under annual burning treatment. Burning frequencies did not impact the extractable Phosphorus (p), Potassium (K), Sodium, soil water repellency and water content significantly (P > 0.05). The risk associated with annual burning showed in this study might facilitate processes such as overflow that lead to soil degradation. Triennial burning in rangeland ecosystem supports soil conservation practices. Further studies that measure the quality of rangeland in triennial burning is necessary.
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Abdulle, Abdinasir M. "A Descriptive Study of Range Livestock Operations in the Somali Central Rangelands." DigitalCommons@USU, 1990. https://digitalcommons.usu.edu/etd/6440.
Full textAbstract:
Information on livestock operations, particularly what kind of livestock operations are practiced in the Somali central rangelands, and how these operations differ for different herders in different vegetation types and farming systems, could serve as a major tool in making management decisions. This study provides a detailed description of range livestock operations in the Somali Central Rangelands. It also answers some important management questions.
Range livestock operations were inventoried through personal interviews with the owners and herders. Data are supplemented by previous nation-wide and regional survey statistics. Herd productivity data which include herd structures, age, age-related sales, slaughters, gifts, and Zakat (religious payment) was derived from the herd recording survey.
The results indicate the need for long term data to serve as a base for decisions concerning range and livestock development.
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Braddick, Lynda. "'We don't go to the casino but we're the biggest gamblers in the world': drivers of change in the Mt Magnet and Upper Gascoyne regions." Thesis, Braddick, Lynda (2006) 'We don't go to the casino but we're the biggest gamblers in the world': drivers of change in the Mt Magnet and Upper Gascoyne regions. Masters by Research thesis, Murdoch University, 2006. https://researchrepository.murdoch.edu.au/id/eprint/431/.
Full textAbstract:
This thesis examines the complex environmental, social, economic and political challenges surrounding sustainable land use of rangelands by European leaseholders in Western Australia. A study of historical, socio-economic and technological events, combined with the development of social values and policy, exposed a broad suite of factors that shaped pastoralism and grazing, and continues to influence development in these regions today. The thesis also explained how the emergence of the sustainable development paradigm is raising awareness of the ways societies define the issues of development, and the influence of this paradigm on attempts to shape change.
Extensive changes in animal production systems have been made in response to complex factors driving change in pastoralism and grazing in recent years. In the Upper Gascoyne, the change to cattle has resulted in extensive changes in infrastructure and raised new hopes for viable production systems in the future. Station amalgamation or sale of stations to Government Departments have been key factors of change in this region. In the Mt Magnet region, wool production remains dominant. However severe drought conditions and declining wool prices are increasingly forcing change to production of feral goats or Damara sheep. Increasing conflict in the rangelands centred around competing claims to land and its use, against a backdrop of dry seasons and changing socio-economics, are escalating leaseholders' fears and concerns about growing community demands for multiple rangeland use. Government approaches now focus on multiple use of rangelands, providing incentives or opportunities to develop alternative methods of use for rangeland resources. However, environmental barriers to sustainable land use and diverse perceptions of sustainability continue to create difficulties for developing effective policies and strategies for change. There is now an urgent need for a paradigm shift in attitudes towards rangelands that promotes more sustainable uses for the land, a greater equality in sharing resources and constructive integration of the values of all rangeland stakeholders.
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Braddick, Lynda. "'We don't go to the casino but we're the biggest gamblers in the world' : drivers of change in the Mt Magnet and Upper Gascoyne regions /." Braddick, Lynda (2006) 'We don't go to the casino but we're the biggest gamblers in the world': drivers of change in the Mt Magnet and Upper Gascoyne regions. Masters by Research thesis, Murdoch University, 2006. http://researchrepository.murdoch.edu.au/431/.
Full textAbstract:
This thesis examines the complex environmental, social, economic and political challenges surrounding sustainable land use of rangelands by European leaseholders in Western Australia. A study of historical, socio-economic and technological events, combined with the development of social values and policy, exposed a broad suite of factors that shaped pastoralism and grazing, and continues to influence development in these regions today. The thesis also explained how the emergence of the sustainable development paradigm is raising awareness of the ways societies define the issues of development, and the influence of this paradigm on attempts to shape change.
Extensive changes in animal production systems have been made in response to complex factors driving change in pastoralism and grazing in recent years. In the Upper Gascoyne, the change to cattle has resulted in extensive changes in infrastructure and raised new hopes for viable production systems in the future. Station amalgamation or sale of stations to Government Departments have been key factors of change in this region. In the Mt Magnet region, wool production remains dominant. However severe drought conditions and declining wool prices are increasingly forcing change to production of feral goats or Damara sheep. Increasing conflict in the rangelands centred around competing claims to land and its use, against a backdrop of dry seasons and changing socio-economics, are escalating leaseholders' fears and concerns about growing community demands for multiple rangeland use. Government approaches now focus on multiple use of rangelands, providing incentives or opportunities to develop alternative methods of use for rangeland resources. However, environmental barriers to sustainable land use and diverse perceptions of sustainability continue to create difficulties for developing effective policies and strategies for change. There is now an urgent need for a paradigm shift in attitudes towards rangelands that promotes more sustainable uses for the land, a greater equality in sharing resources and constructive integration of the values of all rangeland stakeholders.
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Henn, Michael J. "Influence of plains pricklypear cactus on foraging behavior of cattle in eastern Wyoming." Laramie, Wyo. : University of Wyoming, 2008. http://proquest.umi.com/pqdweb?did=1594490441&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Bisrat, Simon Abai. "Primary productivity and grazing capacity of rehabilitated pastures on the open-cut coal mines in central Queensland /." [St. Lucia, Qld. : s.n.], 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16208.pdf.
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Gombakomba, Gift. "Economic valuation of communal rangelands in the Eastern Cape Province of South Africa." Thesis, University of Fort Hare, 2008. http://hdl.handle.net/10353/351.
Full textAbstract:
The exploitation and conversion of rangeland ecosystems is often explained by economists as being the result of an undervaluation of the goods and services provided by the rangelands. Undervaluation of rangelands may contribute to their mismanagement or their transformation to monoculture, such as livestock or gathering. Similarly, this may lead to inappropriate policy recommendations and prescriptions. This study undertakes a valuation exercise in an effort to address causes of undervaluation. The objective of the study is to estimate the annual direct, indirect and non-use values per household of communal rangelands in the Eastern Cape Province, based on both primary and secondary data. The exercise incorporates the two major direct uses, both marketed and non-marketed, of rangelands - livestock and gathering. Contingent valuation method based on stated preferences by individual household was used to value the indirect and non-use values of the communal rangelands (e.g. erosion protection and burial sites). Data was collected using PRAs, structured questionnaires and interviews by trained enumerators. The study shows that half of the households owned livestock, which is the main economic use of the rangelands and gathering of natural resources also made an economic contribution. Every household was involved in collection of range resources such as fuel wood, wild fruits, thatch grass, building poles, hunting, fishing make a significant contribution to the direct use values: in the case of gathering it shows that there is “hidden harvest” of many of the natural resources from the rangelands. Indirect and non-use values are shown to be important in the communal areas but are difficult to quantify; the results of these are based on qualitative analysis. Keywords: communal rangelands, demand curve, direct use values, indirect use values, individuals’ preferences, non-use values, willingness-to-accept and willingness-to-pay.
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Popp, Alexander. "An integrated modelling approach for sustainable management of semi-arid and arid rangelands." Phd thesis, kostenfrei, 2007. http://opus.kobv.de/ubp/volltexte/2007/1510/.
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Knight, Colt Watson. "Intake, Reproductive, and Grazing Activity Characteristics of Range Cattle on Semi-arid Rangelands." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/612879.
Full textAbstract:
ABSTRACT: Study One - Our objective was to characterize mature range cows based on intake and grazing activity. Starting in the early spring of 2013, 4 experiments were conducted. First, mature range cows (n = 137) were fitted with radio frequency identification tags (RFID) and placed in a dry-lot pen equipped with GrowSafe® technology to monitor DMI of alfalfa hay. These data were then used to assign cows a residual feed intake (RFI) value utilizing the National Research Council (NRC) (1996) model to predict intake of beef cattle. Cattle with negative and positive RFI were characterized as low-intake and high-intake, respectively. In addition, the following data were also recorded: weight (kg), age (mo), days pregnant (d), and body condition score (BCS). Second, 30 mature range cattle were selected from the first trial and fitted with pedometers for 7 d to monitor activity with step counts and estimate distance traveled. Third, mature range cows (n = 25) selected from the first trial were fitted with global position system (GPS) collars, and placed on pinyon-juniper rangeland from 20 June 2014 to 17 September 2014. Forth, mature range cows (n = 28) were fitted with GPS collars, and placed on ponderosa pine rangeland from 17 September 2014 to 15 October 2014. Distance traveled, slope, distance from water, elevation data were collected from both GPS trials. Low-intake and high-intake cows consumed 9.3 and 12.2 kg/d, respectively (P < 0.0001). Low-intake cattle became pregnant sooner (P = 0.002) than high-intake cattle (average of 16 d sooner). Cattle age (mo) equaled 90 and 98 for low- and high-intake cows, respectively (P = 0.04). Weight, predicted DMI, and BCS did not differ between groups (P > 0.06). Step counts for low- and high-intake animals were 5839 and 5383 ± 2089, respectively (P = 0.61), and estimated distance traveled was 4.31 and 5.35 ± 1.66 km d⁻¹ for low- and high-intake animals, respectively (P = 0.77). Low-intake cows (6.23 km d⁻¹) traveled farther (P = 0.005) each day than high-intake cows (5.84 km d⁻¹) on pinyon-juniper rangelands, and high-intake cows utilized (P = 0.013) steeper slopes. No differences were detected (P ≥ 0.06) for distance traveled, distance from water, and elevation for cows grazing ponderosa pine rangeland). However, low-intake cattle preferred (P = 0.046) steeper slopes on ponderosa pine rangeland than high-intake cattle. These results indicate that low-intake animals may travel farther on some rangelands and rebreed earlier. Study Two - Commercial grade heifers (n = 173) born and raised on the University of Arizona's V bar V Ranch from 2012 to 2014 were fitted with radio frequency identification tags (RFID) and placed in a drylot equipped with Growsafe® technology (8 bunks) for 60 d in 3 groups based on birth year in order to calculate DMI, residual feed intake (RFI), ADG, G:F, and residual gain (RG). Birth date, birth weight, weaning weight, age at start of trial, initial trial weight, and final trial weights were also recorded. Residual feed intake scores were utilized to place heifers in one of three treatment groups, low-, medium-, and high-intake. Reproductive and calf data were collected on heifers born in 2012. Means for birth date, birth weight, weaning weight, initial weight, final weight, and ADG did not differ among the three treatments. Residual gain for low-, medium-, and high-intake heifers were different (P < 0.05) at 0.07, 0.00, and -0.07 kg d⁻¹, respectively. Low-intake cattle had an improved (P < 0.05) GF ratio of 0.19 when compared to the medium- and high-intake heifers with ratios of 0.15 and 0.13 (P > 0.05), respectively. Differences (P <0. 05) in DMI were detected with low-, medium, and high-intake heifers consuming 5.2, 6.2, and 7.5 kg d⁻¹, respectively. No differences were detected for pregnancy rate, calving rate, percent bred artificial insemination (AI), percent bull calves, calf birth weight, and calf birth date among treatments (P > 0.05).Study Three - Commercially available GPS tracking collars for cattle are cost prohibitive to most researchers. This paper will present a low-cost alternative to those collars (Knight GPS tracking collars), and provide detailed instructions on where to source materials and how to fabricate inexpensive GPS tracking collars. In addition, the two types of collars will be compared in a study where Brangus cattle (n = 8) were each fitted with LOTEK® 3300 and Knight GPS tracking collars for 31 d beginning 14 March 2015 at the Chihuahuan Desert Rangeland Research Center (CDRRC) 37 km north of Las Cruces, New Mexico. Location, slope, distance from water, distance traveled and elevation were recorded every 10 min. A record of GPS fix rate was logged. No differences were detected (P≥0.369) between collar types for location, slope, or distance from water. However, there was a tendency (P = 0.08) for Knight collars to report a lower estimate for distance traveled at 6171 m d⁻¹ compared to Lotek collars at 7104 m d⁻¹. Fix rate was greater (P≤0.001) for Lotek collars compared to Knight collars at 99.9 and 66.2%, respectively. Study Four - Previously characterized commercial cows (n = 26) were placed into either high (positive RFI) or low intake (negative RFI) groups. On 14 May 2015, 13 high- and 13 low-intake cows were fitted with modified igotU GT-120® GPS logging collars. Cattle were then placed on rangeland for 120 d. The first 30 d period animals transitioned from desert shrubland to pinyon-juniper. From 31 to 60 d, animals grazed pinyon-juniper rangeland. Next, during days 61 to 90, animals transitioned from pinyon-juniper to ponderosa pine, and the last 30 d were spent in ponderosa pine. Time periods will be referred to as month 1, 2, 3, and 4 for days 0 to 30, 31 to 60, 61 to 90, and 91 to 120, respectively. Location, slope, distance from water, elevation, and time spent close to water were recorded every 10 min. No differences were observed in the utilization of elevation or distance traveled, or distance from water (P>0.05). Low intake animals used a higher maximum slope (P < 0.05) during month 3, but slope utilization differences were not detected for other portions of the trial (P > 0.05). Study Five - Hereford sires (n = 35) with 7 or more cow offspring on the University of Arizona V bar V ranch in Rimrock, Arizona were tested at Neogen laboratories in Lincoln, NE for an Igenity Gold genetic profile. Their residual feed intake (RFI), ADG, tenderness, marbling score, milk production percent choice, yield grade, fat thickness, ribeye area, heifer pregnancy rate, stayability, maternal calving ease, birthweight and docility were estimated. Sires were given a genetic RFI score based on their RFI profile and placed into one of three intake groups, low (< 0.5 SD), medium (± 0.5 SD) and high (> 0.5 SD). Performance traits of cow offspring (n = 839) from those sires were also compared based on their sire's intake group. No differences (P > 0.05) were detected among sire intake groups for ADG, tenderness, marbling score, percent choice, yield grade, fat thickness, ribeye area, heifer pregnancy rate, stayability, maternal calving ease, birthweight and docility. Residual feed intake differed among groups (P < 0.05), and high intake cattle had more estimated milk production compared to low intake animals (P < 0.05). Cows from low intake sires were born later in the year (P < 0.05). High intake cattle had a higher (P < 0.05) birthweight and survived longer (P < 0.05) in the herd when compared to low and medium intake cows. Genetic RFI and expected milk production were moderately to highly correlated.
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Ntshona, Zolile Mninawa. "The contribution of communal rangelands to rural people's livelihoods in the Maluti district." University of Western Cape, 2001. http://hdl.handle.net/11394/7390.
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Magister Philosophiae (Land and Agrarian Studies) - MPhil(LAS)The contribution of common property resources to rural people's livelihoods is enormous, yet policy makers overlook it. Wild resources, grazing resources and trees provide an important buffer for most rural households. This study investigates the contribution of common property resources, in particular communal rangeland resources, to rural people's livelihoods in the Maluti District of the Eastern Cape, South Africa. Looking at an array of livelihood strategies which people use, the study investigates the proportional contribution of different livelihood strategies with reference to common property resources, specifically wild resources, grazing resources and trees.
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Thrift, Brian Douglas. "Summer diets of sheep grazing spotted knapweed-infested foothill rangeland in Western Montana." Thesis, Montana State University, 2005. http://etd.lib.montana.edu/etd/2005/thrift/ThriftB0505.pdf.
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Paige, Virginia Burton. "Measurement and modeling of the spatial variability of infiltration on rangeland watersheds." Diss., The University of Arizona, 2000. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_2000_342_sip1_w.pdf&type=application/pdf.
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Solomon, Gabrielle Marie. "Assessing the vegetation and soil microbial ecology of renosterveld rangelands around Nieuwoudtville, Northern Cape Province." University of the Western Cape, 2015. http://hdl.handle.net/11394/4764.
Full textAbstract:
Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv and Cons Biol)The Bokkeveld Plateau, a region hosting high plant endemism, is home to two arid mountain centre renosterveld types. One, Nieuwoudtville Shale Renosterveld, has partially been transformed into croplands and pastures, with about 40 % remaining as non-contiguous fragments on privately owned land, and is used as natural rangelands for sheep grazing. The vegetation, soil chemical parameters, and rhizosphere soil microbial ecology of a dominant plant, Eriocephalus purpureus, were assessed. A combination of field sampling and recording, laboratory analyses of soil samples, and interviews were used to glean data. Data were statistically analysed using multivariate techniques. Overall plant species richness did not differ among the study sites, though plant species richness and cover of the different plant growth form categories varied among the sites. Soil chemical parameters varied among sites. Soil chemical and rhizosphere soil microbial parameters co-varied, and showed different profiles among the study sites. High cover of E. purpureus was associated with high microbial enzyme activity, while high cover of (other, non-dominant) non-succulent shrubs was associated with high bacterial functional diversity. Cover of geophytes, Asparagus capensis and perennial grass was associated with high microbial biomass. The findings indicate that E. purpureus-dominated Niewoudtville Shale Renosterveld is heterogeneous not only in terms of vegetation, but also in terms of soil chemical and microbial parameters. The results support the conservation of all fragments of remaining renosterveld, as they may serve as valuable resources of not only plant genetic material but also of soil microbial communities.