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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Short-term effects of prescribed burning on bird communities in coastal Pine Savanna

Faulkner, Douglas W. January 1996 (has links)
A substantial portion of the remaining coastal pine savanna in the southeastern U.S. is burned periodically to maintain habitat for the endangered Mississippi Sandhill Crane (Grus canadensis pulla). However, the effects of this burning on other species of birds are unknown. Therefore, a one-summer study was conducted to determine the short-term response of non-target bird species to changes in vegetation structure due to winter prescribed burning of coastal pine savanna. Eight 25-ha study plots were censused using the spot-mapping technique from May - July 1995 at the Mississippi Sandhill Crane National Wildlife Refuge. More species were observed on old burn sites (burned 1.5 - 3.5 yr prior to the study) than new burn sites (burned the previous winter). Gross vegetation features did not differ between treatments. A total of 17 breeding species were recorded during the study. Although there were no significant differences within individual species' densities, seven species were observed only on old burn sites. Winter prescribed burning affected the presence of only shrub-characteristic species. / Department of Biology
122

Third year effects of shelterwood cutting, wildlife thinning, and prescribed burning on oak regeneration, understory vegetation development, and acorn production in Tennessee

Gordon, Daniel Stuart, January 2005 (has links) (PDF)
Thesis (M.S.) -- University of Tennessee, Knoxville, 2005. / Title from title page screen (viewed on Feb. 1, 2006). Thesis advisor: David S. Buckley. Vita. Includes bibliographical references.
123

Efeitos do fogo sobre assembleias de aves de cerrado / Fire effects on the bird assemblages of cerrado

Reis, Matheus Gonçalves dos 27 March 2015 (has links)
Submitted by Livia Mello (liviacmello@yahoo.com.br) on 2016-09-15T12:31:35Z No. of bitstreams: 1 TeseMGR.pdf: 2131208 bytes, checksum: b36415a6c84dfe47d1989b5ba8da4dcd (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-21T18:29:13Z (GMT) No. of bitstreams: 1 TeseMGR.pdf: 2131208 bytes, checksum: b36415a6c84dfe47d1989b5ba8da4dcd (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-21T18:29:21Z (GMT) No. of bitstreams: 1 TeseMGR.pdf: 2131208 bytes, checksum: b36415a6c84dfe47d1989b5ba8da4dcd (MD5) / Made available in DSpace on 2016-09-21T18:29:27Z (GMT). No. of bitstreams: 1 TeseMGR.pdf: 2131208 bytes, checksum: b36415a6c84dfe47d1989b5ba8da4dcd (MD5) Previous issue date: 2015-03-27 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fire is an ecological factor which seasonally affects fire-prone ecosystems, such as grasslands and open savannas of the Cerrado, and changes some patterns of the biota. This study aimed to investigate the influence of fire on birds that directly use food resources in grasslands of the Serra da Canastra National Park. From December 2012 to January 2015, sampling efforts were carried out in areas burned by wildfires, prescribed burnings (environmental management strategy) and in areas with no influence of fire, in order to record birds in foraging activities, their diet and the use of microhabitat for foraging. The 92 bird species recorded throughout the study exhibited specific results of the occurrence, abundance and response to fire. Considering all birds, the wildfires exerted a deeper and longer (3 - 4 months) influence on assemblage structure, than the prescribed burnings (2 - 3 months). The fire effects on some species of birds were observed in the proportion of food categories consumed, in the diversity of diet items and the microhabitats selected for foraging. The fire response models for birds of prey that occupy the top of the food chain in grasslands indicated a more intense use of food resources in the first post-fire months. Environmental management towards the conservation of grassland ecosystems depends on understanding the effects of recurrent disturbances on native species. / O fogo é um fator ecológico sazonal de ecossistemas pirofíticos, como os campos e savanas abertas do Cerrado, que altera as características do meio biótico. O presente estudo objetivou investigar a influência do fogo nas aves que forrageiam nos campos do Parque Nacional da Serra da Canastra. Entre dezembro de 2012 e janeiro de 2015, foram amostradas áreas atingidas por fogo natural, por queimadas prescritas (para manejo) e também áreas sem influência do fogo, para monitorar as aves que fazem uso direto de recursos alimentares, a dieta e seus micro-habitats de forrageamento. Foram registradas 92 espécies em todo o estudo, com diferentes resultados específicos de ocorrência, abundância e resposta às queimadas. O fogo natural exerceu influência mais profunda e de maior duração (3 - 4 meses) na estrutura das assembleias, do que as queimadas prescritas (2 - 3 meses). Para algumas espécies de aves, os efeitos das queimadas incluíram variação da proporção de tipos de alimentos consumidos, ampliação da diversidade de itens da dieta e alterações de micro- habitats preferenciais de forrageamento. Com relação às aves que ocupam o topo de cadeia alimentar, os modelos de resposta ao fogo apontam para um melhor aproveitamento de recursos alimentares nos primeiros meses pós-fogo. O manejo ambiental para a conservação de ecossistemas campestres depende da compreensão dos efeitos de distúrbios recorrentes na fauna. / CNPq: 141653/2011-6
124

Riskhantering vid naturvårdsbränning : En critical incident studie (CIT) / Risk management in prescribed burning

Andersson, Isac January 2023 (has links)
Naturvårdsbränning är en åtgärd som avser att återskapa effekterna avnaturliga skogsbränder genom att påverka det ekologiska systemet. Trotsfördelarna föreligger risker, såsom oönskad eskalering och spridning av eld,rök och glöd, vilket kan negativt påverka mark, människor och samhällen.Studiens syfte var att undersöka hur ansvariga inom Länsstyrelsen hanterarrisker genom identifiering av kritiska incidenter utifrån Critical IncidentTechnique (CIT) baserad på intervjuer, samt att bidra till att öka den allmännakunskapen kring åtgärden.Resultatet visade att naturvårdsbränningsansvariga tar stor hänsyn till riskeroch arbetar kontinuerligt för att minimera dem. Dock identifierades treförbättringsområden inom riskhanteringsarbetet: säkerhet under bränningar,kommunikation under bränningar och kommunikation med samhället.Förbättringar inom dessa områden kan minimera risker under bränningar,minska oron i samhället och antalet falsklarm samt öka tryggheten igenomförandet för allmänheten och naturvårdsbränningspersonal vidnaturvårdsbränningar. / Hållbart sambruk av räddningsaktörer i svensk landsbygd
125

THE CONSEQUENCES OF A MANAGEMENT STRATEGY FOR THE ENDANGERED KARNER BLUE BUTTERFLY

Pickens, Bradley A. 02 June 2006 (has links)
No description available.
126

Characterization and source apportionment of ambient PM2.5 in Atlanta, Georgia: on-road emission, biomass burning and SOA impact

Yan, Bo 20 August 2009 (has links)
Characterization and Source Apportionment of Ambient PM2.5 in Atlanta, Georgia: On-Road Emission, Biomass Burning and SOA Impact Bo Yan 260 Pages Directed by Drs. Armistead G. Russell and Mei Zheng Various airborne PM2.5 samples were collected in the metropolitan Atlanta and surrounding areas, which are directly impacted or dominated by on-road mobile and other typical urban emissions, regional transport sources, prescribed burning plumes, wildfire plumes, as well as secondary sources with anthropogenic and biogenic nature in origin. Detailed PM2.5 chemical speciation was conducted including over one hundred of GC/MS-quantified organic compounds, organic carbon (OC), water-soluble organic carbon (WSOC), elemental carbon (EC), ionic species, and tens of trace metals. Day-night, seasonal and spatial variations of PM2.5 characterization were also studied. Contributions of PM2.5 major sources were identified quantitatively through the receptor source apportionment models. These modeling results, especially on-road mobile source contributions and secondary organic carbon (SOC) were assessed by multiple approaches. Furthermore, new season- and location-specific source profiles were developed in this research to reflect real-world and representative local emission characterizations of on-road mobile sources, aged prescribed burning plumes, and wildfire plumes. Secondary organic aerosol (SOA), a major component of PM2.5 in the summer, was also explored for sources and contributions.
127

Deer forage available following silvicultural treatments in upland hardwood forests and warm-season plantings

Lashley, Marcus Alan, January 2009 (has links)
Thesis (M.S.)--University of Tennessee, Knoxville, 2009. / Title from title page screen (viewed on Mar. 8, 2009). Thesis advisor: Craig Harper. Vita. Includes bibliographical references.
128

Management of kikuyu (Pennisetum clandestinum) for improved dairy production.

Holliday, Jane. January 2007 (has links)
South African dairy farmers have generally used kikuyu pasture to tide them over from one ryegrass season to the next, and as a result of its resilient nature, have assumed careful management of it to be unnecessary. This has resulted in its mismanagement which is unaffordable in current times where the profitability of dairy farming is increasingly dependent on low input, pasture-based systems. Kikuyu pasture may play a larger role in supplying nutrients to dairy cattle over the summer months in future as the alternative home produced feed sources such as silage and perennial ryegrass become increasingly unaffordable. Improving animal production from kikuyu is difficult as there is little information relating kikuyu pasture management to dairy cow performance. Efficient utilization and quality of temperate pasture have been more comprehensibly researched. The relations discovered between the chemical compounds in temperate grass species have been applied to tropical pastures such as kikuyu with limited success and often confusing results. For example, crude fibre in kikuyu was found to be positively related to digestibility. In South Africa, much research has been done on the use of kikuyu in beef production systems. This information has been applied to dairy farming systems with limited success, owing to the higher metabolic demands of dairy animals. Pasture farming needs to become more precise to improve pasture quality and hence milk yields as research trials focussing on stocking rate and grazing system comparisons have yielded results that are too general with little application at the farming level. A need for integrated and flexible management of animals and pastures has been recognised. The grazing interval is a key aspect in improving pasture and animal performance and fixed rotation lengths and stocking rates have been identified as being detrimental to performance. The relation between growth stage and pasture quality has lead researchers to identify plant growth characteristics, such as pasture height and leaf stage, as signs of grazing readiness. At the four and a half leaves per tiller stage of regrowth, the chemical composition ofthe kikuyu plant is more in line with the requirements ofthe dairy cow, with the leaf to stem ratio at its highest. The primary limitation of kikuyu pasture is a lack of energy, particularly readily fermentable carbohydrate, which makes the fermentation of structural carbohydrates difficult and dry matter intakes are reduced. Other limitations to animal performance include high cell wall constituents, low calcium, magnesium and sodium content and antinutritional factors such as nitrate and insoluble oxalate. These deficiencies and antinutritional factors are in some cases unique to 5 kikuyu pasture, meaning that kikuyu specific supplementation may be the key to improving performance from dairy cattle grazing kikuyu pasture. The objectives are to evaluate current kikuyu management systems in South Africa and their impact on dairy cow performance and to evaluate the use of pasture height and burning as quality control tools. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.
129

Ngorongoro crater rangelands : condition, management and monitoring.

Amiyo, Amiyo T. January 2006 (has links)
The Ngorongoro Crater is a volcanic caldera located within the Ngorongoro Conservation Area in Tanzania. The Crater comprises a flat grassland plain surrounded by steep, bushy walls. It contains extremely high densities of animals and is ecologically the central feature of Ngorongoro Conservation Area. The management of the Ngorongoro Crater has changed significantly in recent times, with cattle being removed and fire excluded about 30 years ago. A detailed vegetation assessment was carried out in the Crater floor by Herlocker & Dirschl in 1972. Since then noticeable changes in vegetation structure and composition, with associated changes in wild herbivore numbers have occurred. The original vegetation survey was repeated in this study as accurately as possible using similar point-based techniques in order to quartify changes and form a baseline for management decision-making and future monitoring. In addition to repeating the vegetation survey, the standing biomass was estimated using a Pasture Disc Meter with associated calibration equations. Data were summarised using multivariate classification and ordination techniques in order to delineate six Homogenous Vegetation Units (HVUs) which can be used for management and management planning purposes, define transects and HVUs in terms of dominant species, describe the main species in relation to their occurrence in different associations and determine the fuel load of the standing crop. A key grass species technique was developed for rapid assessment of the Crater rangeland by the Ngorongoro Conservation Area staff who only need to be familiar with the dominant species. Bush surveys using a point centred quarter technique were conducted along transects in two distinct vegetation types, namely the Lerai Forest and Ngoitokitok Acacia xanthophloea forests and the lower caldera scrub vegetation. The data collected from these transacts were analysed to determine density and composition of the vegetation in the various height classes and the overall structure of the vegetation communities, A range monitoring system in conjunction with a controlled burning programme has been developed to provide an objective means of managing the- rangeland of the Ngorongoro Crater. Data revealed that changes have taken place in the vegetation, with a trend towards dominance by taller grasses and dominance by fewer species. Lack of fire has probably contributed to these changes. Reincorporating fire in the crater is recommended. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.
130

Burning Under Young Eucalypts

Lacy, Philip Alan, Physical, Environmental & Mathematical Sciences, Australian Defence Force Academy, UNSW January 2009 (has links)
Fuels management in eucalyptus plantations is essential to minimise the impact of wildfire. Prescribed burning has the potential to reduce the fuel hazard in plantations, but is not routinely conducted due to concerns relating to tree damage. Through a series of experimental burns, the issues of tree damage are addressed and minimum tree sizes are recommended that are capable of withstanding the effects of low to moderate intensity fires. Data was collected between 2005 and 2007 over six sites, two species, and three age classes. Tree response results came from multiple measurements of over 1700 individual trees. The fuel characteristics commonly found in sub-tropical eucalypt plantations from age four to eleven are described and quantified. These fuel characteristics are related to fire behaviour and new fire behaviour models, specific to young eucalypt plantations, are presented. The fuel characteristics that most influence fire behaviour in young eucalypt plantations are fuel load, fuel height, and fuel moisture content. These characteristics can be used to predict the rate of spread of a plantation fire under benign wind conditions. A novel technique for assessing the extent of stem damage in eucalypts is developed and described. This technique enables immediate assessment of stem damage following fire; previous assessment techniques recommend waiting a considerable period of time (up to 2 years) until dead bark dropped off and fire scars were evident. This new assessment technique is likely to be suitable for post-fire assessment of any eucalypt species and will provide forest managers with the capability of deciding whether to leave a stand to ???grow-on??? or commence recovery operations. Minimum stem sizes recommended to ensure no long-term damage are between 5 ??? 8 cm DBH (diameter at breast height, i.e. 1.3m above ground level) for Eucalyptus dunnii (Dunn???s white gum) and 5 ??? 13 cm DBH for Corymbia spp. (spotted gum) depending on the quantity of fuel around the stem. Stem sizes vary between species because of the variation in bark thickness between species. This thesis provides all the necessary information to conduct prescribed burning operations in young eucalypt plantations.

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