Teses / dissertações sobre o tema "Nature Effect of human beings on"
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1
Redman, William Laurence. "Language, myth, and perceptions in writing about the natural environment". CSUSB ScholarWorks, 2000. https://scholarworks.lib.csusb.edu/etd-project/1593.
2
Surgenor, Hazel. "A phenomenological investigation into the experiences of practicing counselling psychology and psychotherapy out doors". Thesis, Regent's University, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.646073.
Resumo:
This study explores the significance for practitioners of taking their therapeutic work outside of the traditional therapy room, typically into nature spaces, parks or gardens. Attention is paid to the notion of the therapeutic frame and relevant ecopsychology theory. While there is substantial literature around ecotherapy and the benefits of nature to wellbeing, there is relatively little concerning working as a psychotherapist outdoors. The purpose of this research therefore was to address the question of what it is like to take a therapeutic practice out of doors and the potential challenges. Eight semi-structured interviews were conducted with practitioners with experience of working out of doors with clients. Following van Manen’s (1990) hermeneutic phenomenology research methodology, five themes were found: boundaries and new frontiers, fitting in, what ‘they’ think, and who is it for (parts I and II). The research aim, to grasp the meaning of this unconventional practice from the practitioners’ perspective, was mirrored in the analysis which revealed that meaning for the participants is complex and concerns for the client as well as personal concerns were seen as fundamental to the experience. Relationships to and the presence of nature in the work were also recognised as significant and identified a tension around the unquantifiable experience of the ‘soulfulness’ of nature in the work versus the measurable elements of nature that have therapeutic benefit. The scarcity of practitioners working outdoors was attributed to a lack of indoor therapists’ understanding of the processes involved which was seen to impact upon participants’ experiences in their work outdoors. The emergent themes in this research emphasise for counselling psychology an on-going need to review therapeutic dogma, encompass the wider world in the context of therapeutic practice and expand current notions of mental health and psychopathology to engender greater pluralism in theory and practice.
3
Maxey, George F. "Geology as a Georegional Influence on Quercus Fagaceae Distribution in Denton and Coke Counties of Central and North Central Texas and Choctaw County of Southeastern Oklahoma, Using GIS as an Analytical Tool". Thesis, University of North Texas, 2007. https://digital.library.unt.edu/ark:/67531/metadc5144/.
Resumo:
This study elucidates the underlying relationships for the distribution of oak landcover on bedrock and soil orders in two counties in Texas and one in Oklahoma. ESRI's ArcGis and ArcMap was used to create surface maps for Denton and Coke Counties, Texas and Choctaw County, Oklahoma. Attribute tables generated in GIS were exported into a spreadsheet software program and frequency tables were created for every formation and soil order in the tri-county research area. The results were both a visual and numeric distribution of oaks in the transition area between the eastern hardwood forests and the Great Plains. Oak distributions are changing on this transition area of the South Central Plains. The sandy Woodbine and Antlers formations traditionally associated with the largest oak distribution are carrying oak coverage of approximately 31-32% in Choctaw and Denton Counties. The calcareous Blackland and Grand Prairies are traditionally associated with treeless grasslands, but are now carrying oak and other tree landcover up to 18.9%. Human intervention, including the establishment of artificial, political and social boundaries, urbanization, farming and fire control have altered the natural distribution of oaks and other landcover of this unique georegion.
4
Borg, Laura Anne. "Impact of environmental expo on eight graders' self-perceived environmental behaviors". CSUSB ScholarWorks, 2007. https://scholarworks.lib.csusb.edu/etd-project/3218.
5
Warman, Craig S. "Understanding the spatial and temporal variation in anthropogenically induced channel response in the Irwin River catchment". University of Western Australia. School of Earth and Geographical Sciences, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0214.
Resumo:
The Irwin River catchment, located in the central western region of Western Australia, has been the scene of significant geomorphological change over both historical and geological timescales. This thesis focuses on the most recent of these changes, the anthropogenic imprint, through the development of a catchment-scale understanding of system behaviour. Analysis and modelling of changes in the hydrological behaviour of the system indicates that while the Irwin River has displayed a natural susceptibility to large flood events, these have been exacerbated by the widespread clearing of native vegetation throughout the catchment. As a result, when such events do occur, the catchment response is now larger, more direct and has a greater ability to cause erosion. However, the nature and detail of sediment yield processes and stream channel response varies markedly throughout the system. A series of representative channel reaches, as defined by their planform characteristics, geometry and architecture, are presented to illustrate spatial changes in stream channel behaviour. A distinct variation in river morphotypes is seen both downstream throughout the system as well as across the tributary sub-catchments of the Irwin River, Lockier River and Green Brook. This inter and intra sub-catchment variation in stream channel response can be attributed to changes in the boundary conditions and coupling mechanisms in operation throughout the Irwin River system. The pronounced spatial variability in response to human disturbance and the changing nature of catchment-scale connectivity seen in the Irwin River system differs markedly to that reported elsewhere in the literature. Appreciation of the variability in form, behaviour and evolutionary history throughout the Irwin River catchment not only provides the foundation for effective management but also contributes to a wider understanding of fluvial system behaviour. Unlike the majority of existing literature, which tends to identify and measure channel changes in a single catchment where historical variation to the sediment and discharge regime is well known, this study demonstrates the role of boundary conditions in determining the response of the fluvial system to changing environmental controls.
6
Walshe, Bridget. "Driftwood, making sense of a life informed by nature". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0018/MQ51497.pdf.
7
Wada, Yoshihiko. "The myth of sustainable development, the ecological footprint of Japanese consumption". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0015/NQ46441.pdf.
8
Black, Manu School of Biological Earth & Environmental Sciences UNSW. "A late quaternary palaeoenvironmental investigation of the fire, climate, human and vegetation nexus from the Sydney basin, Australia". Awarded by:University of New South Wales. School of Biological, Earth and Environmental Sciences, 2006. http://handle.unsw.edu.au/1959.4/25745.
Resumo:
It is widely believed that Australian Aboriginals utilised fire to manage various landscapes however to what extent this impacted on Australia???s ecosystems remains uncertain. The late Pleistocene/Holocene fire history from three sites within the Sydney Basin, Gooches Swamp, Lake Baraba and Kings Waterhole, were compared with archaeological and palaeoclimatic data using a novel method of quantifying macroscopic charcoal, which is presented in this study. The palynology and other palaeoecological proxies were also investigated at the three sites. The Gooches Swamp fire record appeared to be most influenced by climate and there was an abrupt increase in fire activity from the mid-Holocene perhaps associated with the onset of modern El Ni??o dominated conditions. The Kings Waterhole site also displayed an abrupt increase in charcoal at this time however there was a marked decrease in charcoal from ~3 ka. Lake Baraba similarly had displayed low levels of charcoal in the late Holocene. At both Kings Waterhole and Lake Baraba archaeological evidence suggests intensified human activity in the late Holocene during this period of lower and less variable charcoal. It is hence likely that at these sites Aboriginal people controlled fire activity in the late Holocene perhaps in response to the increased risk of large intense fires under an ENSO-dominated climate. The fire history of the Sydney Basin varies temporally and spatially and therefore it is not possible to make generalisations about pre-historic fire regimes. It is also not possible to use ideas about Aboriginal fire regimes or pre-historic activity as a management objective. The study demonstrates that increased fire activity is related to climatic variation and this is likely to be of significance under various enhanced Greenhouse scenarios. There were no major changes in the composition of the flora at all sites throughout late Pleistocene/Holocene although there were some changes in the relative abundance of different taxa. It is suggested that the Sydney Sandstone flora, which surrounds the sites, is relatively resistant to environmental changes. Casuarinaceae was present at Lake Baraba during the Last Glacial Maximum and therefore the site may have acted as a potential refugium for more mesic communities. There was a notable decline in Casuarinaceae during the Holocene at Lake Baraba and Kings Waterhole, a trend that has been found at a number of sites from southeastern Australia.
9
Conradie, Petra Stefanie. "A psychological inquiry into the relationship between people and the natural environment". Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52126.
Resumo:
Thesis (Msc)--Stellenbosch University, 2001ENGLISH ABSTRACT: There has been a growing awareness of nature among psychologists in recent years, both in terms of how psychology can contribute to the preservation of nature, and utilise its benefits for human beings. In this paper both these aspects of the human-nature relationship are explored. The sense of connectedness between people and nature appears to be the common ground between these two approaches, and it is recommended that experiential as well as cognitive elements of the relationship should be recognised. A limited qualitative pilot study was conducted with five participants of a weekend wilderness experience. All the participants were female first year psychology students. Confirming previous research, this study found that the experience of nature is highly individualised, and includes heightened self-awareness, relaxation, social relationships, spiritual elements, and a sense of connectedness to nature.
AFRIKAANSE OPSOMMING: Sielkundiges raak toenemend bewus van die natuur, in terme van die wyses waarop sielkunde kan bydra tot die beskerming van die omgewing, asook waarop die voordele wat dit vir die mens inhou, benut kan word. Beide aspekte van die verhouding tussen mens en natuur word in hierdie studie ondersoek. Die noue verbintenis tussen mens en natuur blyk die onderliggende faktor tot beide benaderings te wees, en dit word aanbeveel dat die eksperiënsiële sowel as kognitiewe elemente van hierdie verhouding in ag geneem moet word. 'n Beperkte kwalitatiewe loods-studie is uitgevoer met vyf deelnemers van 'n wildemes-ervaring, almal vroulike eerste-jaar sielkunde studente. In ooreenstemming met vorige navorsing het hierdie studie bevind dat die ervaring van die natuur hoogs geïndividualiseerd is, en verhoogde self-gewaarwording, ontspanning, sosiale verhoudings, spirituale elemente, en 'n sin van verbintenis aan die natuur, insluit.
10
Broxson, Bruce Vincent. "Environmental fairs: An examination of the 1999 Inland Empire Environmental EXPO". CSUSB ScholarWorks, 2001. https://scholarworks.lib.csusb.edu/etd-project/1883.
11
Walsh, Megan Kathleen 1976. "Natural and Anthropogenic Influences on the Holocene Fire and Vegetation History of the Willamette Valley, Northwest Oregon and Southwest Washington". Thesis, University of Oregon, 2008. http://hdl.handle.net/1794/9488.
Resumo:
xvii, 382 p. : ill. (some col.), maps. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.The debate concerning the role of natural versus anthropogenic burning in shaping the prehistoric vegetation patterns of the Willamette Valley of Oregon and Washington remains highly contentious. To address this, pollen and high-resolution charcoal records obtained from lake sediments were analyzed to reconstruct the Holocene fire and vegetation history, in order to assess the relative influence of climate variability and anthropogenic activity on those histories. Two sites provided information on the last 11,000 years. At one site at the northern margin of the Willamette Valley, shifts in fire activity and vegetation compared closely with millennial- and centennial-time scale variations in climate, and there was no evidence that anthropogenic burning affected the natural fire-climate linkages prior to Euro-American arrival. In contrast, the fire and vegetation history at a site in the central Willamette Valley showed relatively little vegetation change in response to both millennial- and centennial-scale climate variability, but fire activity varied widely in both frequency and severity. A comparison of this paleoecological reconstruction with archaeological evidence suggests that anthropogenic burning near the site may have influenced middle- to late-Holocene fire regimes. The fire history of the last 1200 years was compared at five sites along a north-south transect through the Willamette Valley. Forested upland sites showed stronger fire-climate linkages and little human influence, whereas lowland sites located in former prairie and savanna showed temporal patterns in fire activity that suggest a significant human impact. A decline in fire activity at several sites in the last 600 years was attributed to the effects of a cooling climate as well as the decline of Native American populations. The impacts of Euro-American settlement on the records include dramatic shifts in vegetation assemblages and large fire events associated with land clearance. The results of this research contribute to our understanding of long-term vegetation dynamics and the role of fire, both natural- and human-ignited, in shaping ecosystems, as well as provide an historical context for evaluating recent shifts in plant communities in the Willamette Valley.
Advisers: Cathy Whitlock, Patrick J. Bartlein
12
Magosha, Tendani Amos. "Social development versus saving nature? : a case study in environmental ethics". Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/49787.
Resumo:
Thesis (MPhil)--University of Stellenbosch, 2003.ENGLISH ABSTRACT: This research project has been purposed at shedding light and bringing clarity and practical resolution to the ethical dilemma brought about by seemingly incompatible principles and value positions associated with the two contentious issues: social development and nature conservation. In view of exposing the contentions between the two above-mentioned value positions, this project has pitted anthropocentrism against biocen trism / ecocen trism. However, as alluded to in this research, many people in developing countries, South Africa included, are victims of poverty and hunger which need redress. Unfortunately the alleviation of the same has been made possible through ruthless exploitation and maximum expansion of natural resources and in the process, the environment suffered much. However, with social development, the natural environment is often sacrificed and conversely with the protection and preservation of nature, man is then condemned to destitution. With the introduction and the case expose forming the introduction of this research project in Chapter 1, Chapter 2 is devoted to the research methodology used throughout this project. Also, given the problem statement, endeavours to search for answers to the central questions are outlined. An analysis of the case study is also made in this chapter. Chapter 3 deals with the weighing of the classical dilemmas namely: anthropocentrism versus biocentrism / ecocentrism and this further entails the notion of justice versus conservation pertaining the case in point. These classical dilemmas are put into critical perspective in Chapter 4 wherein monistic value approaches are exposed in terms of their failures. Precisely, the either-or choices following from pure theoretical principles are put into question with reference to the case under discussion. An alternative, namely the pragmatic approach, which maintains a multiplicity of values, is hereby brought into play. Chapter 5 entails a critical appraisal of the decision to be taken by the Makhado Municipality Council with regard to the development of the shopping complex or the protection of the indigenous tree sanctuary. In conclusion, recommendations and suggestions are stated within the context of the case in point. However, it is imperative to note that these recommendations and suggestions should be read in conjunction with one another, and not in isolation from one another. Furthermore, the same should not in anyway be indiscriminately used as a universal standard in any similar or related case. Further research on this ethical debate is encouraged.
AFRIKAANSE OPSOMMING: Die doel van hierdie navorsingsprojek is om helderheid en 'n praktiese oplossing te kry met betrekking tot die etiese dilemma wat voortspruit uit die oeriskynlik onversoenbare beginsels en waardeposisies wat geassosieer word met twee omstrede kwessies, naamlik sosiale ontwikkeling en natuurbewaring. Met die oog daarop om die kwelpunte rondom bogenoemde twee waardeposisies aan die lig te bring, stel hierdie projek antroposentrisme teenoor biosentrisme / ekosentrisme. Baie mense in ontwikkelende lande, insluitend Suid-Afrika, IS slagoffers van armoede en hongersnood, soos aangedui word in die loop van hierdie navorsing. Hierdie situasie noodsaak regs telling. Pogings om verligting te bring in hierdie verband, lei egter tot die genadelose eksploitasie en maksimum ontwikkeling van natuurlike hulpbronne. In hierdie proses word die omgewing ernstig beskadig. Die ongelukkige toedrag van sake is dus dat sosiale ontwikkeling dikwels geskied ten koste van die omgewing, terwyl die beskerming en bewaring van die omgewing op sy beurt dikwels die mens behoeftig laat. Hoofstuk 1 van hierdie navorsingsprojek bevat 'n inleiding en beskrywing van die geval onder bespreking, terwyl Hoofstuk 2 gewy word aan die navorsingsmetodologie wat in hierdie projek gebruik word. Dit bevat ook 'n skets van die pogings om antwoorde te soek op die sentrale vrae van die probleemstelling, en 'n analise van die gevallestudie. In Hoofstuk 3 word die klassieke dilemmas wat verband hou met die betrokke probleem opgeweeg, naamlik antroposentrisme teenoor biosentrismej ekosentrisme, en die idee van geregtigheid teenoor die idee van bewaring. Bogenoemde klassieke dilemmas word in 'n kritiese lig beskou in Hoofstuk 4 deurdat die tekortkominge van monistiese waardebenaderings uitgewys word. Die 6f-6f keuses wat volg uit suiwer teoretiese beginsels word bevraagteken met verwysing na die geval onder bespreking. 'n Pleidooi word uiteindelik gelewer vir 'n alternatiewe pragmatiese benadering wat eerder 'n veelheid van waardes betrek. Hoofstuk 5 bevat 'n kritiese beoordeling van die keuse wat die Makhado Munisipaliteitsraad moet maak tussen die ontwikkeling van 'n winkelkompleks of die beskerming van 'n inheemse boomreservaat. Ter afsluiting word aanbevelings en voorstelle gemaak in verband met die kwessie onder bespreking. Dit is egter belangrik om daarop te let dat hierdie aanbevelings en voorstelle nie apart van mekaar beskou moet word nie, maar eerder saam gelees moet word. Dit is verder ook belangrik dat die aanbevelings en voorstelle wat met betrekking tot hierdie geval gemaak word nie sonder meer gebruik moet word as 'n universele standaard vir soortgelyke of verwante gevalle nie. Verdere navorsing oor hierdie etiese debat word aangemoedig.
13
Norris, Thomas B. "In the Midst of Spoils: A Composition for Mixed Chorus (SATB) and Small Instrumental Ensemble". Thesis, University of North Texas, 1991. https://digital.library.unt.edu/ark:/67531/metadc935835/.
Resumo:
In the Midst of Spoils is a setting, for SATB choir and small instrumental ensemble, of the poem "Blight," by Ralph Waldo Emerson. Emerson's poem contrasts modern man's exploitative attitude toward nature with the more reverent attitude assumed by ancient or primitive cultures. This setting is in a single movement, approximately twenty minutes in duration, consisting of fifteen distinct sections.
14
Mazzola, Homero Jorge. "Incertezas, bifurcações e dilemas na jornada humana". Pontifícia Universidade Católica de São Paulo, 2017. https://tede2.pucsp.br/handle/handle/20589.
Resumo:
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To build a sustainable future is humanity's great mission in a world characterized by deep social inequalities and environmental changes. Saint-Exupéry said: "The future is not a place where we are going, but a place we are creating. The path to it is not found but built and the act of doing so transforms both the creator and his destiny". Man has the competence to begin its construction, however, must transform himself to make it happen. The purpose of this thesis, elaborated in the form of an essay, is to explore possibilities to build this auspicious future, committed to future generations without under valuating the forces that defend the continuity of our way of life. Three fundamental questions ground this work: where do we come from, what are we and where are we going to, that are structured in three human journeys: past, present and future. In the first we find the lessons and learnings of the evolution process, essential for understanding the present and planning the future. The second journey depicts both the human capacity to transform the planet, adapting it to its needs and desires, as the resistance of those who stand against the continuity of the capitalist world system and defy humanity to metamorphose into a meta system rich in possibilities or to sink in a generalized insignificance. On the last journey, the future, it is approached a vision of the complexity of the world and the human psychic nature, which feed discussions about the individual and collective transformations that must occur to generate a desired future. Man has before him uncertainties, bifurcations and dilemmas, which can result in catastrophe or well-being. The social and climatic deterioration, perverse by itself, can also be good, taking the humanity off passivity, leading it to an overall transformation. A plausible path is a new civilizing context grounded in holistic and ecological educational reform, and structured through a truly global society: the World-Society. There is a great challenge ahead. What will happen, however, only the future will show
Construir um futuro sustentável é a grande missão da humanidade em um mundo assinalado por desigualdades sociais enraizadas e mudanças ambientais profundas. Saint-Exupéry disse: “O futuro não é um lugar para onde estamos indo, mas um lugar que estamos criando. O caminho para ele não é encontrado, mas construído e o ato de fazê-lo transforma tanto o realizador quando o destino”. O homem tem competência para iniciar sua construção, mas deverá se transformar para concretizá-lo. Com esta tese, elaborada na forma de um ensaio, exploram-se possibilidades para se construir esse futuro auspicioso, comprometido com as gerações futuras, sem desprezar as forças que defendem a continuidade do nosso modo de vida. Três questões fundamentais a embasam: de onde viemos, quem somos e para onde vamos, que na tese são abordadas na forma de jornadas humanas: passada, presente e futura. Da primeira extraem-se as lições e aprendizados da história evolutiva, imprescindíveis para se compreender o presente e planejar o futuro. A segunda jornada retrata tanto as profundas transformações que o homem produziu no planeta, adequando-o às suas necessidades e desejos, como as reações dos se posicionam contra a continuidade do sistema mundo capitalista e convidam a humanidade a metamorfosear-se em um metassistema rico em possibilidades ou sucumbir no abismo da insignificância generalizada. Na última jornada, a futura, são abordados conhecimentos sobre a complexidade do mundo e sobre a natureza psíquica humana, que alimentam discussões sobre as transformações individuais e coletivas que devem ocorrer para que se possa engendrar um futuro desejado. O homem tem diante de si incertezas, bifurcações e dilemas, que podem conduzi-lo à catástrofe ou ao bem-estar. A deterioração social e climática, perversa por si, pode ser também um bem e tirar a humanidade da passividade, conduzindo a uma mudança abrangente. Um caminho plausível é um novo contexto civilizatório embasado em uma reforma educacional holística e ecológica, e estruturado através de uma sociedade realmente global: uma Sociedade-Mundo. Há um grande desafio à frente. O que acontecerá, entretanto, só o futuro dirá
15
Sachikonye, Mwazvita Tapiwa Beatrice. "Natural resource use as a coping and adaptation strategy to floods of vulnerable populations in the Eastern Cape". Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1018194.
Resumo:
Many of the anticipated increased occurances of natural hazards are not only a consequence of climate change, but rather of rapid and widespread land cover change and the subsequent loss of the buffering capacity provided by healthy ecosystems against natural hazards. Unplanned and unmanaged developments in informal settlements limit government’s ability to mitigate and manage, pointing towards natural resources as being integral for vulnerable communities in developing countries to cope with and mitigate flood disasters. There is a lack of understanding on how natural resources contribute to resilience of vulnerable populations in the Eastern Cape and how they are impacted by these populations before, during and after a flood shock. There also exists a gap in knowledge on how natural resources can mitigate the physical impacts of flooding in South Africa, more so in the Eastern Cape province. Using household questionnaires and GIS techniques, the strategies that households used to recover from the October 2012-February 2013 flood shocks were investigated in informal settlements of three towns (Grahamstown, Port Alfred and Port St Johns). Within the vulnerability paradigm and the sustainable livelihood framework, the study also quantified and evaluated the relative contribution of natural resources to recovery strategies, and lastly, the study investigated how patterns of land use, state of natural vegetation and household topographical location exacerbated or diminished the physical impacts of flooding. This study found that natural resources contributed up to 70 percent to recovery of households from the flood shock, most of this being to reconstruction of housing structures after the flood, less so to economic recovery. It was also found that at a settlement scale the buffering effect of vegetation, although variable amongst settlements, was significant. Settlements that were dominated by dense bush and small trees experienced up to 46 percent less impacts on their property than those surrounded by bare gravel and impervious roofs with degraded environments. The main findings of the research show that natural resources reduce the vulnerability of households in informal settlements to flooding in two significant ways; by physically mitigating against damage to shelters and by also providing an emergency-net function that substitutes financial capital in households. Their inclusion in disaster management has the potential to encourage the sustainable livelihoods of the urban poor in the Eastern Cape
16
Gude, Andrew Greiff. "An Assessment of the Riparian-influenced Salmonid Habitat Features of Johnson Creek, Portland, Oregon". PDXScholar, 1994. https://pdxscholar.library.pdx.edu/open_access_etds/5232.
Resumo:
Pacific salmon populations in Johnson Creek, Portland, Oregon have been adversely impacted by urbanization, and by residential and agricultural land development. f Ecological impacts include loss or depletion of riparian vegetation features which directly influence stream and associated salmonid ecology. This research examines the nearstream riparian zone's contribution to instream habitat complexity for anadromous salmonids in Johnson Creek. Visual surveys were conducted on over half the stream length. Five features were assessed to determine the extent of riparian influenced stream habitat including, overhead enclosure, overhanging vegetation, undercut banks, and large and small woody debris and root wads. The stream survey showed that areas of riparian-influenced habitat are spatially intermittent and present in areas of the least stream disturbance. Suitable riparian habitat is limited to locations where there is minimal riparian disturbance, property management, and channelization. I Although salmonid populations have been reduced, insufficient riparian influenced salmonid habitat features are not the primary limiting factor on salmon populations. Other factors such as pollution, sedimentation, hatchery fish introduction, low flows, inadequate food supplies, high stream temperatures, repress wild salmon populations.
17
Broshot, Nancy Ellen. "The Effects of Urbanization and Human Disturbance Upon Plant Community Structure and Bird Species Richness, Diversity, and Abundance in a Natural Forested Area (Forest Park) in Portland, Oregon". PDXScholar, 1999. https://pdxscholar.library.pdx.edu/open_access_etds/3962.
Resumo:
The effects of urbanization and continual human disturbance on the plant and avian communities of Forest Park and forested lands surrounding Portland, Oregon, were studied. I examined characteristics of plant and avian communities at 25 sites, 24 which were in Forest Park and surrounding areas and one which was in the Ancient Forest Preserve (old-growth stand) northwest of Forest Park. Data were analyzed using multiple regression, ANOV A, and Bonferonni/Dunn. Seven variables were selected representing different urbanization gradients. An additional covariable coded for the old-growth stand, allowing it to be used as a control.
Many tree variables, especially those related to shade-tolerant species, were positively correlated with both the distance from downtown Portland and the number of houses in the surrounding area, and negatively correlated with the distance from the nearest forest edge; however, many shrub and herbaceous variables were negatively correlated with the distance from downtown Portland. Species diversity for herbaceous and shrub species was greater at more urban sites, but diversity of trees was lower at more urban sites. There were significantly more non-native species of plants in the city section. I found significantly fewer saplings and small trees, especially shade-tolerant species, in the section of Forest Park closest to downtown Portland, although tree mortality was positively correlated with distance from Portland.
Summer bird data revealed significant increases in the abundances of urban and edge species at more urban sites, with concomitant reductions in forest species. There were significantly more ground gleaning birds and short distance migratory species. I also found a significantly greater abundance of birds in the old-growth stand during the winter. This increase was positively correlated with the depth of snow in the nearby Cascade Mountains.
My results indicate that Forest Park is apparently progressing in a normal successional pattern with the exception of the city section. The reduction in shade tolerant saplings and small trees in the city section suggest that rate of succession has been slower at more urban sites. Avian data suggest that urbanization affects bird species abundance and guild composition in the more urban areas.
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Debastiani, Júnior José Roberto [UNESP]. "Diversidade das assembléias de Cladóceros (Crustacea, Branchiopoda) de áreas adjacentes a trechos lóticos e reservatórios da Bacia do Rio Prata (Argentina, Brasil, Paraguai e Uruguai". Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/123956.
Resumo:
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000822496.pdf: 12679327 bytes, checksum: 27cc99f52b9d72b91606bd5e0c2d2e6a (MD5)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
A bacia do Rio da Prata é a segunda maior da América do Sul e a mais densamente povoada. Nela são desenvolvidas diversas atividades humanas e são observadas variações climáticas e geológicas devido à grande extensão espacial. Esta bacia possuiu inúmeras áreas alagadas adjacentes aos seus principais rios, os quais foram intensamente barrados em alguns trechos. Nesse tipo de habitat é marcante a presença de macrófitas aquáticas, às quais estão associados inúmeros organismos, dentre eles os Cladocera, crustáceos microscópicos cuja maior diversidade pode ser encontrada em águas continentais. Apesar de presentes em muitos estudos no continente Sul Americano, esse grupo raramente tem sua taxonomia e distribuição geográfica analisadas, principalmente em grandes escalas como a de uma bacia do porte da do Rio da Prata. Os objetivos principais desse trabalho são: (1) analisar a distribuição e padrões de riqueza de espécies de Cladocera na bacia; (2) analisar os padrões de associação dos Cladocera com as macrófitas aquáticas das áreas adjacentes e (3) avaliar a influência das atividades humanas nas comunidades desses microcrustáceos. Foi encontrado um elevado número de espécies na bacia, constituindo praticamente dois terços do total conhecido para a região Neotropical. Foram identificadas três espécies possivelmente desconhecidas à ciência. Os dados obtidos demonstraram que os Cladocera apresentam um padrão de distribuição de espécies na bacia diferente daquele proposto em estudos biogeográficos recentes. A associação das diferentes espécies de Cladocera com as macrófitas vai além da complexidade da mesma, sendo o tipo de planta importante para a composição específica. Em relação à influência das atividades humanas sobre os Cladocera fica claro que a presença de reservatórios, uso intensivo dos canais fluviais e proximidade a grandes centros urbanos, causam marcadas alterações na estrutura ...
FAPESP: 09/11781-8
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Debastiani, Júnior José Roberto. "Diversidade das assembléias de Cladóceros (Crustacea, Branchiopoda) de áreas adjacentes a trechos lóticos e reservatórios da Bacia do Rio Prata (Argentina, Brasil, Paraguai e Uruguai /". Botucatu, 2014. http://hdl.handle.net/11449/123956.
Resumo:
Orientador: Marcos Gomes NogueiraCoorientador: Lourdes Maria Abdu El-moor Loureiro
Banca: Raoul Henry
Banca: Odete Rocha
Banca: Antonio Leão Castilho
Banca: Claudia Costa Bonecker
Banca: Virgínia Sanches Uieda
Banca: Eliana Aparecida Panarelli
Banca: Silvia Maria Caglierani Casa Nova
Resumo: A bacia do Rio da Prata é a segunda maior da América do Sul e a mais densamente povoada. Nela são desenvolvidas diversas atividades humanas e são observadas variações climáticas e geológicas devido à grande extensão espacial. Esta bacia possuiu inúmeras áreas alagadas adjacentes aos seus principais rios, os quais foram intensamente barrados em alguns trechos. Nesse tipo de habitat é marcante a presença de macrófitas aquáticas, às quais estão associados inúmeros organismos, dentre eles os Cladocera, crustáceos microscópicos cuja maior diversidade pode ser encontrada em águas continentais. Apesar de presentes em muitos estudos no continente Sul Americano, esse grupo raramente tem sua taxonomia e distribuição geográfica analisadas, principalmente em grandes escalas como a de uma bacia do porte da do Rio da Prata. Os objetivos principais desse trabalho são: (1) analisar a distribuição e padrões de riqueza de espécies de Cladocera na bacia; (2) analisar os padrões de associação dos Cladocera com as macrófitas aquáticas das áreas adjacentes e (3) avaliar a influência das atividades humanas nas comunidades desses microcrustáceos. Foi encontrado um elevado número de espécies na bacia, constituindo praticamente dois terços do total conhecido para a região Neotropical. Foram identificadas três espécies possivelmente desconhecidas à ciência. Os dados obtidos demonstraram que os Cladocera apresentam um padrão de distribuição de espécies na bacia diferente daquele proposto em estudos biogeográficos recentes. A associação das diferentes espécies de Cladocera com as macrófitas vai além da complexidade da mesma, sendo o tipo de planta importante para a composição específica. Em relação à influência das atividades humanas sobre os Cladocera fica claro que a presença de reservatórios, uso intensivo dos canais fluviais e proximidade a grandes centros urbanos, causam marcadas alterações na estrutura ...
Abstract: Not available
Doutor
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Acott, Timothy G. "Soil micromorphology and image analysis : a study of Bronze Age to recently improved soils at Lairg, Sutherland, Scotland". Thesis, University of Stirling, 1993. http://hdl.handle.net/1893/1784.
Resumo:
The applications of multispectral and morphometric image analysis to soil thin section descriptions is examined. It is shown that unsupervised classification and contrast stretching can be used to enhance and label features of interest. Morphometric measurements, allow the shape and abundance of features in thin sections to be compared and statistical relationships established. This method of analysis offers a precision beyond that which is possible using a qualitative approach. Using soil micromorphology as the main analytical technique a case study was carried out to evaluate the applicability of image analysis to an investigation of an archaeological site at Lairg in northern Scotland. The interactions of anthropogenic activity and pedogenesis since the Bronze Age is examined. The condition of the soils prior to the Bronze Age is not known because no buried soils predated this period. Evidence suggests that in freely draining situations complete podzols might have formed by this time. During the Bronze and Iron Age intensive cultivation of soils occurred with associated erosion. In areas of the site, where human activity is dated to the Post Medieval period, deepening of A horizons is apparent and the soils are maintained as Brown Podzols. In many areas where human activity stops stagnopodzols are the dominant soil type. The potential of image analysis to aid soil micromorphological descriptions is demonstrated. Contrast stretching aided a qualitative subdivision of thin section slides during the case study. Morphometric analysis confirmed a relationship between shape of voids and c/f ratios in an Iron Age buried A horizon, A PM buried A horizon and an undated deep topsoil. It is concluded that the full benefits of image analysis, when used as a routine tool to aid thin section descriptions, will only be realised when procedures become more interactive and processes can be speeded up.
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Riyahi, Sepand. "Local adaptation by birds to human-altered habitats: the great tit and the house sparrow as model species". Doctoral thesis, Universitat de Barcelona, 2017. http://hdl.handle.net/10803/456899.
Resumo:
Human-altered environments have expanded rapidly in the past decades and made a huge impact on living organisms. Inhabiting in such a habitat can modify different traits in animals, allowing for a better adaptation to these human-altered environments. In the first part of this thesis I investigated patterns of recent (contemporary) adaptation to urban habitats, focusing on the role of behavioural, genetic and epigenetic variation in great tits. In the second part of the thesis I investigated patterns of adaptation to human-made habitats in a larger time-scale, focusing on the origin and expansion of the house sparrow, which has been for ages a human commensalism. I additionally checked the effect of methylation variation on the rapid expansion and high phenotypic variation of house sparrow in the Palearctic region. Regarding the great tit I found that urban-dwelling birds are more explorative in novel environments and bolder in front of new objects than forest individuals. I found several epigenetic modifications and genetic polymorphisms possibly related to novelty seeking behaviour in the great tits. Our results suggested that epigenetics adjustment can be different in the urban-dwelling great tits in comparison to the forest birds. Furthermore, we investigated the possible polymorphisms in the Melanocortin-1 gene in the great tit to relate it with the size of the black belly stripe, which had previously been found to differ between urban and forest individuals. However, results showed that there is no polymorphism in this gene in relation to the size of the black belly stripe. In relation to the house sparrow, we found that the commensalism of this species with humans has a single origin and probably initiated in the Middle East. Then, it expanded rapidly in the Palearctic region with the aid of agriculture and human civilizations expansion. In addition, we discovered that the genome-wide methylation pattern of house sparrows has a general stability within five subspecies in the Middle East but we found high level of variation at the individual level within populations which likely happened randomly rather than due to selection. Our results indicate that variation in DNA methylation does not strictly follow subspecies designations. We have detected correlation between methylation level and some morphological traits such as standardized bill length and we suggest that part of the high morphological variation in the native populations of the house sparrow is influenced by differentially methylated regions in specific loci throughout the genome. We also detected seven differentially methylated loci diverged by subspecies and also three loci differentiated by commensal or non-commensal status.
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Winther, Anne M. "Survive or thrive : creating options for sustainable communities in rural Scotland". Thesis, University of Stirling, 2014. http://hdl.handle.net/1893/21186.
Resumo:
Environmental and socio-economic crises are creating compelling needs for radical social change. This project investigated the options and barriers for three Scottish rural communities (Fintry, Killin and Kinlochleven) to become sustainable and thrive in a future resource-constrained world. A unique, holistic and mixed methods approach was used to assess baseline sustainability, envision and model futures and develop possible options for sustainability. Central to this investigation was the development of a strong and holistic model of a sustainable community: the sustainable community design (SCD). This framework shaped the assessment of each community’s baseline sustainability. Sustainability was measured for the ten aspects of the SCD using a scorecard approach with a basket of indicators populated by primary data (collected in a household survey) and secondary data (national statistics). Sustainable consumption was analysed using the Resources and Energy Analysis Programme (REAP) to generate each community’s ecological footprint (EF) and results were compared to current estimates of per capita world biocapacity to gauge sustainability. Even the most sustainable community was only sustainable in three out of ten of the SCD’s aspects and this community had the highest EF. Although the most deprived community had the lowest EF, it was unsustainable in all ten SCD aspects. The results reflected the heterogeneity of rural communities and complexity of sustainability measurement. The SCD scorecard approach for sustainability measurement was shown to be sensitive and robust and can be applied to rural communities across Scotland. Future visions were created in focus groups, in which participants were asked to envision what their community would need to thrive in 2030 under the scenario of peak oil and a low carbon economy. Vision ideas and examples of best practice and technological innovation were used to create narrative scenarios for modelling transport, food and energy futures. The scenarios’ EFs were calculated in REAP for three discrete levels of change: a marginal change, a step change and radical transformation. The results suggested that radical transformation is required for communities to become sustainable. Key features are likely to be re-localised and highly co-operative societies, which utilise technological innovations (such as electric cars powered by renewable energy) and share resources to maximise opportunities for living in rural areas. A community’s transformation is likely to be bespoke and require local control, requiring changes to governance and supportive policy. Key barriers identified were availability of affordable technological innovations, energy injustice, power to achieve self-determination, community governance, property rights and sustainability literacy. A process model, incorporating the SCD scorecard approach, was proposed for furthering sustainable community development and research. In taking an interdisciplinary and mixed methods approach, this study has pioneered a novel approach to the holistic enquiry of the options for creating sustainable rural communities.
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Beyers, Christelle. "Exploring a sustainability imagination : a perspective on the integrating and visioning role of stories and symbolism in sustainability through an alternative education case study". Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/936.
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Dyer, Siobhan Margaret. "Population size, demography and spatial ecology of cheetahs in the Timbavati Private Nature Reserve, South Africa". Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1002058.
Resumo:
The cheetah (Acinonyx jubatus) has experienced a drastic decline in numbers over the last 20 years globally and is currently listed as vulnerable by the International Union for the Conservation of Nature (IUCN). In South Africa, there are only an estimated 763 free-ranging cheetahs and conflict with humans is arguably the most significant reason for this low number. The aim of my study was to determine the population size and demographic characteristics of the cheetah population within the Timbavati Private Nature Reserve (TPNR), South Africa, and to contribute to a better understanding of cheetah space use and habitat selection. The research was conducted on TPNR between November 2009 and June 2011 and I used a photographic survey to assess cheetah population size and demographic characteristics. Location data was obtained by collaring two adult male cheetahs with GPS/GSM collars and ad hoc sightings data from across the reserve for an adult female with cubs and three adolescent females. A relatively high minimum population density of 4.46 cheetahs/100km² was estimated, signifying a relatively healthy cheetah population. The sex ratio data indicated a higher male to female ratio and an average litter size of three cubs. The relatively high cub survival rate and density is promising in terms of the status of species within the area, as the data denote the success and potential persistence of the species. Cheetah home ranges varied between 20.97km² for the female with cubs and 659.65km² for the younger collared male. Season did not appear to be a determining factor in terms of home range sizes for the three social groups within the TPNR. However, the males did show a slight increase in their home range sizes during the dry season when resources where presumably more widespread. My results indicate that the cheetah is an adaptable species, flexible in behaviour and able to tolerate a variety of habitat types. Such knowledge is fundamental for planning and implementing the effective management and conservation of cheetahs in South Africa.
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Tauler, Ametller Helena. "Viabilitat demogràfica i efecte dels canvis ambientals antropogènics en la distribució, dieta i condició física d'una població d'aufrany Neophron percnopterus en expansió = Demographic viability and effect of anthropogenic environmental changes in the distribution, diet and body condition of an expanding population of Egyptian Vulture Neophron percnopterus". Doctoral thesis, Universitat de Barcelona, 2018. http://hdl.handle.net/10803/586283.
Resumo:
En la present tesi s’avaluen les causes del creixement demogràfic de la població d’aufrany (Neophron percnopterus) a Catalunya, així com també s’estudia la influència dels canvis ambientals antropogènics, en especial dels abocadors, sobre la dieta, la condició física i la presència de contaminants dels individus de la població.
En primer lloc, es du a terme un anàlisi demogràfic de l’aufrany a l’àrea d’estudi per a veure quins són els principals factors que han causat el seu augment poblacional. Els resultats, demostren que la població d’aufrany ha augmentat d’1 a 22 parelles entre els anys 1988 i 2012 i, que per explicar el creixement observat, ha estat necessària una elevada supervivència dels individus adults així com l’arribada d’individus d’altres àrees.
A banda, s’estudia l’expansió poblacional de l’espècie per tal de veure quines són les característiques ambientals de les noves àrees de colonització, avaluant concretament la influència dels recursos alimentaris d’origen antròpic, definits amb el nom de Predictable Anthropogenic Food Subisdes (PAFS). Els resultats apunten que els PAFS tenen un paper important en la selecció territorial de l’aufrany, ja que els territoris de cria estan situats més a prop dels abocadors del que s’esperaria a l’atzar. Tot i així, altres factors ambientals com les zones rocoses orientades al sud, la urbanització i la proximitat a conespecífics també tenen importància en la selecció dels territoris.
A més, per tal d’avaluar quin és l’ús que les parelles d’aufrany fan dels abocadors s’analitza la dieta dels polls de la població. Per a fer-ho, es comparen dues metodologies, l’anàlisi d’isòtops estables i l’anàlisi de restes convencional. Els resultats obtinguts amb els dos mètodes coincideixen en que el consum de restes d’abocador pot arribar a ser elevat en algunes parelles (al voltant d’un 50 %).
Un cop coneguda la dieta dels individus, la següent qüestió que s’aborda és quina influència té el fet d’alimentar-se en abocadors sobre la seva condició física. Els resultats indiquen que la proporció de la dieta que prové d’abocadors és el factor principal que afecta els indicadors fisiològics dels individus. Els polls alimentats a partir de residus humans presenten nivells més baixos d’algunes vitamines i carotens, els quals tenen funcions importants com a defenses antioxidants, propietats immunoestimulants i finalitats ornamentals. A més a més, els polls alimentats en abocadors, semblen estar més ben alimentats i experimentar menys períodes de dejú que els individus que no utilitzen aquests recursos.
Finalment, s’analitzen les concentracions de diferents famílies de contaminants; metalls, compostos organoclorats (Ocs), èters difenílics polibromats (PBDEs) i substàncies perfluorades (PFAS) en els individus de la població així com la seva influència en la fisiologia dels individus. La major part dels nivells detectats de contaminants es troben per sota el límit de detecció o són, en general, baixos. Així, tot i que l’acumulació de contaminants en polls d’aufrany a l’àrea d’estudi no sembla estar causant greus efectes negatius sobre la seva fisiologia, si que es detecta que els individus de les zones més humanitzades, presenten uns nivells de PFAS més elevats.
Aquesta tesi aporta informació rellevant en dos sentits. En primer lloc, perquè descriu el cas particular de l’augment demogràfic d’una espècie amenaçada que es troba en declivi a gran part de la seva distribució mundial; el coneixement de les causes que han provocat aquesta tendència positiva, podria ser molt útil per a la conservació de l’aufrany en d’altres àrees on està disminuint. En segon lloc, perquè s’avalua quines són les implicacions d’alimentar-se en abocadors. En un món antropitzat on els escenaris de la distribució dels recursos estan canviant constantment, aportar coneixement sobre la influència dels abocadors pot ser clau per a dissenyar mesures de gestió futures de les espècies amenaçades o plaga que utilitzen aquests punts.The Egyptian Vulture (Neophron percnopterus) is an endangered scavenger species that in recent years has experienced a population growth and an expansion of its range in Catalonia (NE of Iberian Peninsula). In this thesis the demographic and environmental factors that could have caused this increase are studied. Population models showed that, to explain the observed population growth, it has been needed a high adult survival and the arrival of immigrants from other populations. Also, it was assessed the influence of predictable anthropogenic food subsides, specifically landfills, to the distribution, diet and body condition of individuals of our study population. First, it was observed that occupied territories were located closer landfills than expected by chance, so the location of these installations are determining the distribution of breeding pairs. After, it was assessed the contribution of food from landfills to Egyptian Vulture diet using both conventional analyses and stable isotope analysis. Results showed that that both methods provide similar contributions of food from landfills in this species’ overall diet, and also a high proportion of food derived from landfills (nearly 50%) was detected in some breeding pairs. The next step was to determine the influence of diet from landfills to the body condition of nestlings, using morphometrical and physiological approaches. It was found that the contribution of landfills to the diet was the main factor that explained body condition of individuals, especially for its effect to the antioxidant metabolism. Also, nestlings that fed in landfills seem to be better fed. Finally, concentrations of different families of Persistent Organic Pollutants and metals were analysed in nestlings of our population and it was found that levels of pollutants were in general low, so they not appear as susceptible to cause detrimental effects to nestlings’ physiology. Overall, this thesis contributes to the knowledge of conservation status of Egyptian Vulture in Catalonia and it can be useful to assess the influence of landfills to vulture species.
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Pagès, Escolà Marta. "New insights into the ecology and conservation of bryozoans: from global diversity patterns to the responses to anthropogenic stressors in the Mediterranean Sea = Noves aproximacions a l’ecologia i conservació dels briozous: des dels patrons globals de diversitat fins les respostes als impactes humans al Mar Mediterrani". Doctoral thesis, Universitat de Barcelona, 2019. http://hdl.handle.net/10803/668538.
Resumo:
Marine ecosystems are directly threatened by multiple and interactive human stressors at global and local scales. Hence, it is vital to study biodiversity and ecological patterns through a multi-disciplinary approach, from understanding global diversity patterns to evaluating the ecological responses of species to different impacts in order to protect marine ecosystems. In this thesis, we focused on bryozoans, an abundant group of sessile marine invertebrates distributed worldwide, but generally understudied. Accordingly, in this thesis we provide different approaches to understand discovery and macroecological patterns at global scales, and the response of species to different stressors at local scales, combining the use of open databases, the in situ monitoring of natural populations, experiments in aquaria and the development of restoration techniques.
At global scale, in Chapter I we unraveled discovery patterns of fossil and extant bryozoans and showed the highest number of fossil species described, highlighting that the current biodiversity represents only a small proportion of Earth’s past biodiversity. Beyond these differences, both groups showed an increase in the taxonomic effort during the past century. Despite this progress, future projections of discovery patterns of both groups showed a large proportion of species remaining to be discovered by the final of this century. In Chapter II, most of the global diversity patterns of marine sessile groups, including bryozoans, showed a non-unimodal latitudinal pattern with a dip in the number of species at the equator and a higher diversity in the Southern ocean. Moreover, this region will be less affected by global warming at the final of this century. In contrast, our analyses showed that the most sampled region for both marine sessile species and bryozoans was North Temperate Atlantic, highlighting the importance to quantify environmental drivers considering sampling effort biases. For this reason, we tested the effect of using the popular method of rarefaction (ES50) vs the incorporation of a frequency index of sampling effort as co-variate in quantitative models. Despite we obtained the same best predictors for both approaches (depth, nitrate, and SST), the models using the correction of sampling biases through frequency index showed better fitting, encouraging to incorporate this methodology in future studies.
Focusing on the Mediterranean Sea, in Chapter 3 we studied the responses of bryozoans to different stressors. First, we showed that two abundant and common bryozoans, Pentapora fascialis and Myriapora truncata, displayed different tolerances to warming through the combination of in situ monitoring and experiments in aquaria. Moreover, in Chapter 4 the in situ monitoring of Pentapora fascialis populations revealed its fast population dynamics, with high recruitment and growth rates, and a high capacity of recovery. Accordingly, we observed an increase in the density of its populations in the Medes Island Marine Reserve since the 1990s. However, we evidenced that diving can impact on the density, recruitment, survival, and size of the colonies, registering lower values in frequented localities. Our results highlight that the over frequentation of divers compromises the future viability of populations, highlighting the need to explore other active management strategies. For this reason, in Chapter 5, we tested and developed different restoration techniques for P. fascialis, focusing on the recruitment enhancement through the installation of recruitment surfaces and the transplantation of adult colonies. The successful results and the affordable and economic cost of tested techniques aim to encourage the managers of Marine Protected Areas to apply similar methodologies.
The results presented in this thesis show the importance to combine different approaches to understand the global and local ecological patterns of understudied but abundant groups, such as bryozoans. Our findings enlarge the current ecological knowledge of bryozoans at different scales, and highlight that more effort is needed to protect vulnerable populations.Els ecosistemes marins estan sotmesos a múltiples impactes a escales locals i globals i que a més interaccionen entre ells. Per aquesta raó, és important estudiar els patrons de biodiversitat i ecològics a través d’una aproximació multi-disciplinària, que pot anar des d’entendre els patrons de diversitat global fins a avaluar les respostes ecològiques de les espècies enfront diferents impactes, per així conservar i gestionar adequadament les comunitats marines. Fins aquest moment, la majoria d’estudis relacionat s’han centrat en grups carismàtics i populars, com ara les gorgònies, els coralls, les macroalgues o les fanerògames marines. En canvi, aquesta tesis es centra en l’estudi dels briozous, un grup abundant de invertebrats sèssils marins distribuïts per tot el món, però generalment poc estudiats. Per aquesta raó, el principal objectiu d’aquesta tesis és utilitzar diferents aproximacions per entendre els patrons de descobriment i macro-ecològics a escala global, i la resposta a diferents impactes a escala local, combinant el ús de bases de dades globals, el seguiment in situ de les poblacions, experiments en aquaris i el desenvolupament de tècniques de restauració. A més, la present tesis vol proporcionar un marc de treball per identificar, gestionar i conservar les poblacions vulnerables en el context de l’augment de les activitats humanes que afecten els ecosistemes marins. Els resultats presentats en aquesta tesis mostren la importància d’aplicar diferents aproximacions per entendre els patrons ecològics globals i locals de grups abundants però poc estudiats, com són els briozous. Els resultats obtinguts contribueixen a augmentar el coneixement dels patrons ecològics dels briozous a diferents escales, i mostren que cal més esforç per protegir les poblacions vulnerables. Així, mesures de gestió adaptativa i de restauració i són necessàries per promoure la conservació dels ecosistemes marins en un context de impactes creixents derivats de l’activitat humana tant a escales locals com globals.
27
Yeung, Chun-yu. "When nature and human beings meet ... in Sha Lo Tung". Click to view the E-thesis via HKUTO, 2004. http://sunzi.lib.hku.hk/hkuto/record/B31987394.
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Yeung, Chun-yu, e 楊臻宇. "When nature and human beings meet ... in Sha Lo Tung". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B31987394.
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Rocaspana, Rafel. "Efectos de las puntas de caudal hidroeléctricas (hidropuntas) en las poblaciones de trucha común (Salmo trutta) de ríos pirenaicos". Doctoral thesis, Universitat de Barcelona, 2017. http://hdl.handle.net/10803/406950.
Resumo:
Las puntas de caudal de origen hidroeléctrico (hidropuntas) provocan cambios de distinta intensidad y alcance, a todos los niveles de organización de los ecosistemas fluviales donde tienen lugar. No hay en condiciones naturales, una situación comparable y por tanto no hay ni especies ni ecosistemas específicamente adaptados a ella. Comprender en profundidad la magnitud de los efectos es la única opción para poder definir y llevar a la práctica, medidas eficaces y equilibradas entre la producción de energía hidroeléctrica y la conservación de los ecosistemas fluviales.
Esta Tesis Doctoral pretende mejorar el conocimiento sobre los efectos de las hidropuntas en las poblaciones de trucha (Salmo trutta) de ríos pirenaicos de la vertiente mediterránea. Para ello se ha estudiado la dinámica poblacional, la movilidad y la alimentación de la trucha en un tramo con hidropuntas, comparándolo con uno de control y otro de referencia más alejado pero dentro de la misma cuenca. Los resultados obtenidos indican que las hidropuntas tienen una influencia directa y muy significativa sobre la organización del cauce y el hábitat físico, lo que a su vez determina cambios en las densidades de trucha, especialmente de alevines (disminución de frezaderos, condiciones hidráulicas desfavorables,…). Estos efectos, no obstante, se atenúan río abajo, especialmente cuando se incorporan tributarios con aporte de carga sedimentaria. Se ha constatado también que la estructura demográfica de la trucha en tramos sujetos a hidropuntas es más estable al paso de crecidas naturales de cierta entidad.
Las poblaciones de trucha de los tramos altos de los ríos Flamisell y Noguera Pallaresa tienen un carácter marcadamente sedentario a lo largo del año. El 76,8% de ejemplares realizan movimientos inferiores a 20 m y solo un 3,6% los realizan superiores a 200 m. Las hidropuntas no parece que influyan directamente sobre los patrones de movilidad de las truchas. Sí que se observan diferencias considerables en la amplitud de los movimientos relacionados con la época de freza, significativamente mayores en el tramo de hidropuntas, sin duda debido a la falta de zonas aptas para la freza.
A escala de una hidropunta, la movilidad de las truchas es mayor durante la primera mitad de la punta de caudal, especialmente en sentido río arriba. Coincide con el incremento de la deriva de macroinvertebrados y se manifiesta como el momento de mayor ingesta de alimentos por parte de las truchas. En general, en el tramo con hidropuntas las truchas presentaron mayor tasa de consumo de alimentos y una dieta más generalista y heterogénea, lo que indica un comportamiento alimentario oportunista. Las hidropuntas no parecen causar impactos negativos directos en la alimentación de la trucha adulta.
De acuerdo con los resultados obtenidos, algunas actuaciones sobre el hábitat físico en tramos con hidropuntas como la incorporación de gravas, la restitución de zonas de freza, la creación de refugios, etc., pueden contribuir sustancialmente a la conservación de las poblaciones de trucha de estos tramos sometidos a un régimen de caudales altamente fluctuante.Les puntes de cabal d'origen hidroelèctric (hidropuntes) provoquen canvis de diferent intensitat i abast, a tots els nivells d'organització dels ecosistemes fluvials on tenen lloc. No hi ha en condicions naturals, una situació comparable i per tant no hi ha ni espècies ni ecosistemes específicament adaptats a ella. Comprendre en profunditat la magnitud dels efectes és l'única opció per poder definir i portar a la pràctica, mesures eficaces i equilibrades entre la producció d'energia hidroelèctrica i la conservació dels ecosistemes fluvials. Aquesta tesi doctoral pretén millorar el coneixement sobre els efectes de les hidropuntas en les poblacions de truita (Salmo trutta) de rius pirinencs del vessant mediterrani. Per això s'ha estudiat la dinàmica poblacional, la mobilitat i l'alimentació de la truita en un tram amb hidropuntes, comparant-lo amb un de control i un altre de referència més allunyat però dins de la mateixa conca. Els resultats obtinguts indiquen que les hidropuntes tenen una influència directa i molt significativa sobre l'organització de la llera i l'hàbitat físic, el que al seu torn determina canvis en les densitats de truita, especialment d'alevins (disminució de zones de fressa, condicions hidràuliques desfavorables, ...). Aquests efectes, però, s'atenuen riu avall, especialment quan s'incorporen tributaris amb aportació de càrrega sedimentària. S'ha constatat també que l'estructura demogràfica de la truita en trams subjectes a hidropuntas és més estable al pas de crescudes naturals de certa entitat. Les poblacions de truita dels trams alts dels rius Flamisell i Noguera Pallaresa tenen un caràcter marcadament sedentari al llarg de l'any. El 76,8% d'exemplars realitzen moviments inferiors a 20 m i només un 3,6% els realitzen superiors a 200 m. Les hidropuntes no sembla que influeixin directament sobre els patrons de mobilitat de les truites. Sí que s'observen diferències considerables en l'amplitud dels moviments relacionats amb l'època de fresa, significativament majors en el tram de hidropuntas, sens dubte a causa de la manca de zones aptes per a la fresa. A escala d'una hidropunta, la mobilitat de les truites és major durant la primera meitat de la punta de cabal, especialment en sentit riu amunt. Coincideix amb l'increment de la deriva de macroinvertebrats i es manifesta com el moment de major ingesta d'aliments per part de les truites. En general, en el tram amb hidropuntes les truites van presentar una major taxa de consum d'aliments i una dieta més generalista i heterogènia, la qual cosa indica un comportament alimentari oportunista. Les hidropuntes no semblen causar impactes negatius directes en l'alimentació de la truita adulta. D'acord amb els resultats obtinguts, algunes actuacions sobre l'hàbitat físic en trams amb hidropuntes, com ara la incorporació de graves, la restitució de zones de fresa, la creació de refugis, etc. poden contribuir substancialment a la conservació de les poblacions de truita d'aquests trams sotmesos a un règim de cabals altament fluctuant.
Peak flows of hydroelectric origin (hydropeaking) lead to changes of different intensity and scope at all levels of organization of fluvial ecosystems where they occur. In natural conditions, there is no comparable situation and therefore no species or ecosystems are specifically adapted to it. A deep understanding of the magnitude of the effects is the only option in order to define and implement effective and balanced measures between hydroelectric power production and the conservation of river ecosystems. This Doctoral Thesis aims to improve the knowledge of the effects of hydropeaking on populations of brown trout (Salmo trutta) of the Pyrenean rivers in the mountain Mediterranean catchments. To do so, the population dynamics, mobility and feeding of the brown trout have been studied in a stretch with hydropeaking, comparing it with a control stretch and another benchmark stretch further away but still within the same watershed. The results obtained show that hydropeaking has a direct, significant influence on the organization of the watercourse and the physical habitat, which in turn determines changes in brown trout population densities, especially of juveniles (fewer spawning grounds, unfavourable hydraulic conditions,...). These effects, however, are attenuated downstream, especially when tributaries contribute sedimentary load. It has also been found that the demographic structure of brown trout in stretches of river subject to hydropeaking is more stable in front of the occurrence of natural flooding of a certain magnitude. The brown trout populations in the upper sections of the Flamisell and Noguera Pallaresa rivers have a markedly sedentary character throughout the year. A 76.8% of specimens move less than 20 m and only 3.6% move further than 200 m. Hydropeaking does not seem to directly influence brown trout mobility patterns. However, considerable differences are observed in the breadth of movements associated with the spawning season, being significantly higher in the section of hydropeaking, doubtless due to the lack of areas suitable for spawning. On the scale of a hydropeak, the mobility of the brown trout is greater during the first half of the flow peak, especially in the upstream direction. It coincides with the increase of macroinvertebrate drift and manifests itself as the time of greatest food intake by brown trout. In general, in the stretch with hydropeaking the brown trout had a higher rate of food consumption and a more general and heterogeneous diet, indicating opportunistic feeding behaviour. Hydropeaking does not seem to cause direct negative impacts on adult brown trout feeding. According to the results obtained, acting on the physical habitat in stretches with hydropeaking as the incorporation of gravel, restoring spawning grounds, the creation of shelters, etc., may contribute substantially to the conservation of the populations of brown trout in these stretches with a highly fluctuating flow regime.
30
Vess, Matt. "Defending our place in nature mortality salience and environmental concern /". Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/5995.
Resumo:
Thesis (M.A.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on November 9, 2007) Includes bibliographical references.
31
Watson, Stephen C. L. "The impact of multiple stressors on coastal biodiversity and associated ecosystem services". Thesis, University of St Andrews, 2017. http://hdl.handle.net/10023/16817.
Resumo:
Marine and coastal ecosystems are subject to diverse and increasingly intensive anthropogenic activities, making understanding cumulative effects critically important. However, accurately accounting for the cumulative effects of human impacts can be difficult, with the possibility of multiple stressors interacting and having greater impacts than expected, compounding direct and indirect effects on individuals, populations, communities and ecosystems. Assessment of multiple stressors therefore requires extensive scientific research that directly tests how single or multiple ecological components are affected by stressors, both singly and when combined, and as a consequence, cumulative effects assessments are now increasingly included in environmental assessments. Currently, there is a need to assess these at larger spatial scales, with additional research also urgently needed on the responses of ecological components, processes and functions to single and cumulative stressors. As cumulative environmental impacts could be better addressed by regional stressor effects assessments that combine methods for predicting multiple pressures on ecosystem recovery alongside degradation, this study used several separate approaches that can be used in parallel to give support for local management measures. I tested four completely different methods - a range of multi-metric indices, a food web model (Ecopath), a predictive model (Ecosim) and a Bayesian Belief Network model. Each approach was tested and compared in two shallow water estuarine systems, in Scotland and England, initially concerning the impact of nutrient enrichment and subsequent recovery and was followed by an investigation of how the addition of multiple stressors (nutrient levels, temperature and river-flow rates) would impact the future state of each system. The response to stressors was highly context dependent, varying between and within geographic locations. Overall, each of the four different approaches complemented each other and gave strong support for the need to make big reductions in the pressures and to consider trade-offs between impacting pressures. The models and tools also indicate that in order to reach an improved overall environmental state of each ecosystem, a focus on nutrient reductions are likely to be the most effective of the controls on stressors explored and that cumulative effects of the management of nutrient inputs and increased water temperatures and river-flow are likely to exist.
32
Van, Winkle Jill Elise. "Informal Trails and the Spread of Invasive Species in Urban Natural Areas: Spatial Analysis of Informal Trails and their Effects on Understory Plant Communities in Forest Park, Portland, Oregon". PDXScholar, 2014. https://pdxscholar.library.pdx.edu/open_access_etds/1841.
Resumo:
The risk of spread and establishment of invasive species to interior habitat within urban parks is of great concern to park managers and ecologists. Informal trails as a vector for this transmission are not well understood. To characterize effects of informal trails on understory plant communities, I conducted a study of the informal trail network in Forest Park, Portland, Oregon. The system of 382 informal trails was mapped and evaluated qualitatively, and from this population a systematic sample was selected for analysis. To identify hotspots of informal trail activity, showing the relationship of informal trails to formal trails, other park features, and trail use level, I evaluated all mapped trails using line density spatial analysis tools. To characterize understory communities, thirty transects were placed along informal trails, with paired transects along nearby formal trails for comparison. I measured percent cover by species for non-graminoid understory plants, and percent total plant cover at different structural layers, for quadrats at regular intervals from the trail edge. I calculated richness and Shannon-Weaver diversity for non-graminoid understory plants. For community analysis, species were grouped by dispersal strategy, native status, and growth form.
Observations from system mapping suggest that "hidden" behaviors drive many informal trails: bathroom stops, party spots, waste dumping, and camps make up 28% of all informal trails. Trails to private property are few but represent over 29% of total trail length. Informal trail density is highest along Balch Creek. Hotspots of informal trail presence are associated with trailheads, trail intersections, and water access. Quadrats located within one meter of informal trails showed higher richness and diversity due to increased number of introduced and ruderal species. Formal trails exhibit these same patterns to a stronger degree and over a greater distance (two meters) from the trail edge. Distance from trail edge explained variation in plant communities when grouped by dispersal type, but not by growth form. This study shows that although informal trails are widely distributed throughout the park, they are concentrated in high use areas. The presence of informal trails leads to significant changes in Forest Park plant communities that favor invasive and ruderal species, but these effects appear limited to two meters from the trail edge.
33
Haas, Ryan. "Cultured growth Nature as cultural object /". PDF viewer required Home page for entire collection, 2007. http://archives.udmercy.edu:8080/dspace/handle/10429/9.
34
Zenteno, Devaud Lisette. "Cambios en la posición trófica del lobo común sudamericano (Otaria flavescens) en respuesta a la explotación masiva de mamíferos marinos y pesca industrial". Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/398133.
Resumo:
Los depredadores marinos pueden cambiar su dieta a través del tiempo como consecuencia de cambios antropogénicos y naturales, por lo que un punto de referencia histórico aporta información básica y necesaria para comprender el papel ecológico que desempeñan estos individuos dentro del ecosistema que habitan. En las costas del Atlántico sudoccidental los registros zooarqueologicos e históricos revelan una importante explotación de los lobos marinos sudamericanos por parte de los colonizadores europeos y en menor grado por parte de los aborígenes cazadores recolectores, sin embargo, poco se sabe sobre la influencia de estas explotaciones sobre la dieta de esta especie. Debido a que los lobos marinos sudamericanos se caracterizan por tener un amplio nicho trófico, el determinante principal de la composición de sus dietas es la competencia intraespecifica, por lo que se espera que estos animales muestren un cambio en la posición trófica asociado a la caza indiscriminada por parte de los colonizadores europeos, y un impacto menor sobre sus poblaciones y dietas como resultado de la caza aborigen. En esta tesis doctoral se realizaron análisis de isótopos estables de carbono y nitrógeno en muestras zooarqueológicas y modernas, provenientes del centro-norte y sur de Patagonia Argentina con el objetivo de reconstruir la dieta de los lobos marinos sudamericanos desde el Holoceno tardío al presente. Los resultados revelan un marcado aumento del nivel trófico durante el siglo XX, el cual podría estar relacionado con una disminución del tamaño poblacional del lobo común sudamericano, como consecuencia de la explotación comercial, y una reducción de la competencia intraespecífica. Al contrario, tanto en Patagonia norte-centro como en Patagonia sur, las poblaciones de lobos marinos sudamericanos mostraron una estabilidad en la dieta durante varios milenios de explotación aborigen. Asimismo, no se observaron cambios significativos durante las últimas tres décadas en las razones isotópicas del hueso de machos jóvenes y adultos de lobo marino sudamericano procedentes del sur de Brasil a pesar de un dramático incremento en el desarrollo de la pesquería demersal, lo cual sugiere que la población regional se encuentra muy por debajo de la capacidad de carga. Estos resultados confirman la importancia de los análisis retrospectivos de las razones isotópicos para inferir cambios en la dieta de los depredadores oportunistas, y para identificar la transición ecológica entre ecosistemas prístinos y modificados antropogénicamente.Marine predators may undergo remarkable dietary changes through time as a result of both anthropogenic and natural changes in the environment, and hence, a historical point of reference provides the necessary basic information to understand the ecological function of individuals in the ecosystem. In the south-west Atlantic coasts, zooarchaeological and historical records revealed a significant exploitation of South American sea lions by European colonizers and to a lesser extent by aboriginal hunter-gatherers, however, little is known about the influence of these exploitations on the diet of sea lions. Because South American sea lions have been reported as broad spectrum, the intraspecific competition plays an important role in the composition of their diets. It is therefore expected a change in the trophic position of these animals associated with the indiscriminate hunting by Western sealing, and less impact on their populations and diets as a result of aboriginal exploitation. Stable isotope ratios of carbon and nitrogen in archaeological and modern samples from northern-central and southern Patagonia, Argentina have been used in this doctoral thesis to reconstruct the dietary changes of the South American sea lion from the late Holocene to the present in the southwestern Atlantic. Results show a marked increase in trophic level during the twentieth century which might be related to the smaller population size resulting from modern sealing and the resulting reduced intraspecific competition. On the contrary, populations of South American sea lions from both in north-central Patagonia and southern Patagonia showed a stability in the diet for several millennia of aboriginal exploitation. Furthermore, no major changes were detected in the diet of male South American sea lions during the past three decades from southern Brazil despite a dramatic increase in the development of demersal fisheries, suggesting that population levels may be below of their optimal carrying capacity Results confirmed the importance of retrospective analysis of the stable isotope ratios to infer changes in the diet of opportunistic predators, and to identify the ecological transition between pristine ecosystems and anthropogenically modified.
35
Guttmann, E. B. "Continuity and change in arable land management in the Northern Isles : evidence from anthropogenic soils". Thesis, University of Stirling, 2001. http://hdl.handle.net/1893/3551.
Resumo:
Human activity can affect the soil in ways which are traceable long after the land has been given over to other uses, and past land management practices can be reconstructed by investigation of these relict characteristics. In some regions the addition of fertilising materials to the arable soils has created artificially deepened anthropogenic topsoils which can be over 1m thick. Such relict soils are found all over the world, and are widespread in north-western Europe. This work focuses on the anthropogenic soils in the Northern Isles, which were formed from the Neolithic period up until the 20th century. Three multi-period sites were investigated using thin section micromorphology, organic/inorganic phosphate analysis, soil magnetism, particle size distribution, loss on ignition and soil pH. Current views of anthropogenic soil formation, based on pedological investigation and historical documentary sources, are that they are formed as a result of the addition of domestic animal manures and turf used as animal bedding to arable areas. This project sets out to test the hypothesis that in fact anthropogenic soils are the result of a wide range of formation processes which took place over extended periods of time. The hypothesis has been tested by analysing soils and associated middens of different dates, which have been sealed and protected by blown sand deposits. The results have shown that in the Neolithic period arable soils were created by cultivating the settlement's midden heaps as well as by adding midden material to the surrounding soils. In the Bronze Age human manure, ash and domestic waste were spread onto the fields around the settlements to create arable topsoils up to 35cm thick. In the Iron Age arable agriculture was intensified by selective use of organic manures on one of the sites investigated, but organic waste material was not used as efficiently as it was in later periods, and on both sites it was allowed to accumulate within the settlements. In the Norse period, when the intensive system used in historical times appears to have originated, organic waste may have been used more efficiently. These changes appear to reflect a greater organisation of land resources and manuring strategies and increased demand for arable production over time.
36
Robins, Dan. "The debate over human nature in warring states China". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B29872388.
37
Havyarimana, François. "La contribution de l'instabilité sociopolitique dans l'anthropisation des paysages au Burundi: dynamique spatiale et biodiversité". Doctoral thesis, Universite Libre de Bruxelles, 2015. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209113.
Resumo:
La zone tropicale connaît à l’heure actuelle une réduction catastrophique de la superficie des écosystèmes forestiers qui jouent pourtant un rôle essentiel dans la régulation climatique et qui constituent un réservoir inestimable de la biodiversité. Les causes de cette déforestation sont multiples et complexes. Même si l’agriculture constitue l’une des causes majeures de la déforestation dans la plupart des régions tropicales, l’Afrique sub-saharienne a connu des influences exceptionnelles liées aux conflits sociaux qui ont entrainé un afflux massif de réfugiés ou de déplacés internes. Au Burundi, l’instabilité sociopolitique survenue en 1993 a entrainé un déplacement massif de la population constituée essentiellement d’agriculteurs. Une partie de cette population déplacée s’est réfugiée à l’extérieur du pays tandis qu’une autre s’est retrouvée dans des camps de déplacés à l’intérieur du pays. L’objectif de cette étude est de caractériser la dynamique spatio-temporelle de l’occupation du sol au sud et sud-est du Burundi en mettant un accent particulier sur l’influence de cette migration forcée de la population. La dynamique et la biodiversité végétale de la forêt de Bururi qui est située dans ce paysage anthropisé ont également été analysées. Sur la base de 6 images satellitaires et des observations sur le terrain, cette étude montre que le sud et sud-est du Burundi est caractérisé par une augmentation de l’anthropisation au fil du temps. L’impact négatif de l’instabilité sociopolitique sur la végétation naturelle a été mis en évidence par la diminution du degré d’anthropisation au fur et à mesure que la distance aux camps de déplacés augmente. Il est également confirmé par le fait que l’anthropisation de la zone située autour des camps est plus importante pour les années qui ont suivi le déclenchement de l’instabilité sociopolitique par rapport aux années antérieures. Ainsi, les résultats de cette étude ont permis de confirmer que les camps de déplacés ont significativement contribué à la dynamique de l’occupation du sol dans cette région. La création de nouvelles parcelles agricoles ainsi que la recherche du bois de chauffe autour des camps sont à l’origine de cette forte déforestation. Cette étude montre également que la distribution d’abondances des plantes de la forêt de Bururi est conforme à la distribution log série, ce qui constitue également un indicateur de sa perturbation malgré son statut d’aire protégée. L’agrégation de certaines de ses espèces arborescentes pourrait être l’une des conséquences de ces perturbations anthropiques. En outre, la prépondérance de certains arbustes pionniers généralement indicateurs des forêts tropicales africaines secondarisées, serait un indicateur d’une perturbation anthropique récente qui pourrait être attribuée à cette instabilité sociopolitique. La mise en place d’une politique nationale de réhabilitation des anciens emplacements des camps ainsi que la restauration des espèces menacées s’avèrent par conséquent indispensables./Nowadays, tropical zones are characterized by a catastrophic decline of forest ecosystems areas which play however an important role in climate regulation and biodiversity conservation. There are numerous and complex causes of deforestation. Even if agriculture is one of the main causes of deforestation in most tropical regions, sub-saharan Africa is known to have exceptional influences related to social conflicts that led to a massive flow of refugees or internal displaced population. In Burundi, socio-political instability which occurred in 1993 also led to massive waves of displaced people, essentially farmers. A part of them fled to foreign countries whereas others were kept gathered in camps throughout the country. The present study aims to analyze the land cover spatiotemporal dynamics in south and southeast of Burundi and is particularly focused on the influence of this population forced to migrate. Dynamics and plant diversity of Bururi forest located in this anthropogenic landscape were also investigated. The study combines six Landsat multispectral satellite images analysis with fielding observations. The study highlights an increase in natural vegetation disturbance by anthropogenic activities over time. The negative impact of socio-political instability has been demonstrated by an anthropization decrease when the distance from the camps increases. It is also confirmed by a high anthropogenic pressure in the camp’s surrounding zone during the period that followed the outbreak of the socio-political instability than in previous years. This result confirms that displaced population camps have significantly contributed to the land cover dynamic in the south and southeast of Burundi. Agricultural and domestic firewood collecting activities in camp’s surrounding zone are the main causes of deforestation during instability period. The observed plant species abundance distribution in Bururi forest was found similar to the log series model which also suggests the impact of disturbance on the plant abundance distribution despite the status of this ecosystem as protected area. The spatial aggregation of some of its tree species would be considered as a consequence of anthropogenic disturbance. In addition, the observed pioneer shrubs usually characteristics of secondary African tropical forests can be considered as anthropogenic recent disturbance indicators and would be attributed to the socio-political instability impact. This study recommends the establishment of a national rehabilitation policy of those disturbed zones around the camps and restoration of endangered plant species.Doctorat en Sciences agronomiques et ingénierie biologique
info:eu-repo/semantics/nonPublished
38
Ndaro, Lucas Burenga. "The nature of human death the case for prefall mortality /". Theological Research Exchange Network (TREN), 2006. http://www.tren.com/search.cfm?p036-0363.
39
Johnson, Anthony S. "The effect of lunar phase on student behavior". Menomonie, WI : University of Wisconsin--Stout, 2005. http://www.uwstout.edu/lib/thesis/2005/2005johnsona.pdf.
40
Colin, Muñoz Nicole. "Evaluación de los impactos antrópicos en los ríos mediterráneos: bioindicadores, biomarcadores e índices de calidad biótica". Doctoral thesis, Universitat de Barcelona, 2017. http://hdl.handle.net/10803/404731.
Resumo:
Los ríos mediterráneos han experimentado una larga historia de impactos antropogénicos, incluyendo la captación de agua, la contaminación y la liberación de especies no nativas. Es crítico detectar, monitorear y evaluar estos impactos para desarrollar estrategias de manejo efectivas y proteger la fauna altamente endémica y en peligro de extinción de estos ecosistemas. Los actuales esquemas oficiales de biomonitoreo están firmemente arraigados en los llamados índices de calidad biótica (ICBs), que utilizan taxones acuáticos como indicadores de la degradación ambiental. Para el cumplimiento de la Directiva Marco Europea del Agua, se han desarrollado más de 200 IBQ en los Estados miembros para adaptar esta filosofía de monitoreo a las particularidades de cada tipología de río. A pesar de su fácil aplicabilidad, la capacidad diagnóstica de estos protocolos es limitada en sistemas de baja riqueza de especies, como las comunidades de peces de los ríos mediterráneos. Además, estos protocolos han demostrado ser aproximaciones diagnósticas gruesas a nivel comunitario que típicamente no logran detectar efectos sutiles en el nivel del organismo. En el mejor de los casos, cuando detectan deficiencias, es probable que sea demasiado tarde para tomar medidas de conservación para evitar la extinción local. Considerando que las poblaciones de peces de agua dulce están disminuyendo en todo el mundo, existe la necesidad urgente de desarrollar herramientas de monitoreo más efectivas. Además, es necesario armonizar mejor los esquemas actuales de monitoreo con la teoría ecológica para mejorar nuestra capacidad predictiva de cómo las actividades humanas, incluyendo el cambio global, afectan los ríos mediterráneos y sus servicios ecosistémicos. El objetivo principal de esta tesis doctoral es explorar la idoneidad de las herramientas alternativas de biomonitoreo en los ríos mediterráneos, así como identificar las combinaciones de estresores que puedan intensificar el impacto ecológico de las actividades humanas en la biota. Utilizamos un enfoque multidisciplinario basado en ICBs (Capítulo 1), diversidad de rasgos funcionales (Capítulo 2), y biomarcadores (Capítulos 3 y 4), que mostró claramente el poder de diagnóstico superior de las herramientas alternativas de biomonitoreo.
41
Louw, E. J. M. "Climate change in the Western Cape : a disaster risk assessment of the impact on human health". Thesis, Stellenbosch : University of Stellenbosch, 2007. http://hdl.handle.net/10019.1/1158.
Resumo:
Thesis (DPhil (Geography and Environmental Studies))—University of Stellenbosch, 2007.Background The Disaster Management Act (Act 57 of 2002) instructs a paradigm shift from preparedness, response and recovery towards risk reduction. In order to plan for and mitigate risks, all spheres of government must firstly assess their hazards, vulnerabilities, capacity to cope and therefore risks. Studies in this regard, in South Africa, have however only focussed on current risks. Climate Change has now been accepted by leading international studies as a reality. Climate change can impact upon many aspects of life on earth. Studies to quantify the impact of climate change on water resources, biodiversity, agriculture and sustainable development are steadily increasing, but human health seem to have been neglected. Only general predictions, mostly regarding vector-borne disease and injury related to natural disasters are found in literature. Studies in South Africa have only focussed on malaria distribution. Most studies, internationally and the few in South Africa, were based on determining empirical relationships between weather parameters and disease incidence, therefore assessing only the hazard, and not the disaster risk. Methodology This study examines the impact of climate change on human health in the Western Cape, within the context of disaster management. A qualitative approach is followed and includes: · A literature overview examining predicted changes in climate on a global and regional scale, · A discussion on the known relationships and possible impacts climate change might have on human health, · A disaster risk assessment based on the status quo for a case study area, the Cape Winelands District Municipality, · An investigation into the future risks in terms of health, taking into account vulnerabilities and secondary impacts of climate change, resulting in the prioritisation of future risks. · Suggestions towards mitigation within the South African context. Results The secondary impacts of climate change were found to have the larger qualitative impact. The impact of climate change on agriculture, supporting 38% of the population can potentially destroy the livelihoods of the workforce, resulting in poverty-related disease. Other impacts identified were injuries and disease relating to temperature, floods, fire and water quality. Conclusion Risk is a function of hazard, vulnerability and capacity to cope. The impact of an external factor on a ‘spatial system’ should be a function of the impacts on all these factors. Disasters are not increasing because of the increase in the frequency of hazards, but because of the increasing vulnerability to hazards. This study illustrated that the major impacts of the external factor could actually be on the vulnerabilities and the indirect impacts, and not on the hazard itself. Climate change poses a threat to many aspects of the causative links that should be addressed by disaster management, and its impacts should be researched further to determine links and vulnerabilities. This research also illustrates that slow onset disasters hold the potential to destroy just as much as extreme events such as Katrina, Rita or a tsunami. It also reiterates that secondary impacts may not be as obvious, but are certainly not of secondary importance.
42
Diallo, Hady. "Influence des gradients anthropique et géomorphologique sur la variation de la biodiversité végétale dans la réserve de biosphère de la boucle du Baoulé au Mali: cas de la réserve de Fina". Doctoral thesis, Universite Libre de Bruxelles, 2014. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209343.
Resumo:
Les travaux de recherche ont été menés dans la réserve de biosphère de la boucle du Baoulé (RBBB) au Mali. Cette réserve est constituée de 3 aires, Badinko, Kongosambougou et Fina. Cette étude a été faite dans l’aire de Fina, la plus importante pour sa richesse en faune. La péjoration des conditions climatiques et les impacts des pressions anthropiques croissantes ont entraîné une dégradation des écosystèmes en particulier la biodiversité végétale. L’objectif de notre recherche est d’étudier l’influence des gradients anthropique et géomorphologique sur la variation de la biodiversité végétale dans la RBBB. Elle contribuera à la caractérisation et à l’évaluation de l’état actuel de la végétation dans une perspective de conservation durable des ressources végétales en particulier la biodiversité. Nous sommes partis de l’idée que les aires protégées constituent des espaces témoins de conservation des milieux naturels qui, comparés aux milieux perturbés permettraient de caractériser l’état d’évolution de la biodiversité végétale. Deux approches ont été utilisées pour aborder cette étude :l’approche synchronique et l’approche diachronique. Un recensement et une classification des espèces ont été effectués en s’appuyant sur le dispositif de zonage d’une réserve de biosphère basée sur les degrés de pression (régimes de protection) et la situation géomorphologique. Puis une quantification des variations de pressions liées aux activités anthropiques a été faite. Nos résultats ont montré que les facteurs structurants de la végétation varient suivant la géomorphologie et surtout le dispositif de zonage (gradient anthropique). C’est dans les milieux perturbés que la diversité est élevée, mais avec un niveau d’organisation peu homogène comparativement aux milieux non perturbés. L’intensification actuelle des pressions dans les milieux perturbés et la dégradation des formations végétales qui en résulte n’entraînent pas actuellement dans la réserve une baisse de diversité. Aussi, dans les conditions écologiques locales pratiquement semblables dans la réserve, le zonage caractérisant les niveaux d’anthropisation est autant important que les facteurs texture du sol qui sont liés aux conditions géomorphologiques dans la structuration floristique. Les résultats phytosociologiques ont montré l’individualisation de 10 groupements végétaux dont 6 en milieux perturbés avec une tendance à la dégradation de la végétation et sa transformation en savane arbustive et 4 en milieux non perturbés marqués par la disparition des formes de végétation originelles. La plus forte densité en espèces est observée dans les groupements végétaux des unités de plaine et de vallée pour l’ensemble des 3 zones. C’est dans ces unités également que la surface terrière pour les arbres de plus de 8 m et la valeur pastorale sont importantes. La diminution du recouvrement des espèces herbacées de bonne valeur fourragère en particulier les pérennes est corrélée aux perturbations liées aux intenses activités anthropiques (agricole et pastorale par exemple). Ces activités engendrent la dégradation du milieu, une baisse de la valeur pastorale qui est indépendante de la biodiversité. Les dynamiques temporelles de la composition du paysage forestier de la réserve ont montré une ouverture du paysage caractérisée par une extension des superficies cultivables de la zone de transition vers la zone protégée ainsi que la réduction de la superficie des savanes arborées et la transformation progressive du paysage en savane arbustive. L’étude a permis de comprendre que le dispositif législatif classique de protection ne correspond pas à la réalité de terrain. De façon générale, l’influence des gradients géomorphologique et surtout anthropique est perceptible sur la structure de la flore et de sa diversité.
Une extension de notre approche d’étude dans les réserves de Badinko et de Kongosambougou permettra d’asseoir un dispositif de suivi de l’évolution spatio-temporelle de la végétation et de poser les bases d’une politique rationnelle de conservation de la réserve de biosphère de la boucle du Baoulé.
Mots clés :Anthropisation, diversité floristique, dynamique spatiale, géomorphologie, réserve de Fina, Mali.
ABSTRACT
The research was conducted in the Fina, part of biosphere reserve of « boucle du Baoulé » (RBBB) in Mali. This reserve consists of 3 areas, Badinko, Kongosambougou and Fina. Fina area is the most important for its rich fauna, this study was done. The climatic conditions pejoration and the impacts of increasing human pressures have led to ecosystem degradation, particularly plant biodiversity of the Fina reserve. In this study we have updated data on plant diversity and its variation based on the device of biosphere reserve zoning based on the pressure degree (protects systems). The objective of this thesis was to test the main hypothesis that protected areas are witness spaces of natural settings conservation that, compared to the disturbed areas, would characterize plant biodiversity evolution. Two approaches were used to address this study: synchronic and diachronic approach. Our results showed that the vegetation structural factors vary with the environment (zones) and geomorphology. The correlations between vegetation and ecological factors showed that the disturbance gradient is a major factor in the floristic variability. Human pressure intensification in disturbed habitats and resulting vegetation degradation do not currently induce any decrease of diversity in the reserve. In local similar environmental conditions as is the Fina reserve case, zoning characterizing the human impact levels is as important as the soil texture factors that are related to geomorphological conditions in the floristic structure. The phytosociological results showed the individualization of 10 plant groups in disturbed habitats, including 6 with a tendency to shrubby savanna and 4 in undisturbed environments marked by the disappearance of the vegetation original forms. The highest density of species is observed in plant communities of the plain and valley units in all the three zones. It is also in these units that basal area for trees over 8 m and pastoral value are important. The herbaceous species of good fodder value recovery reduction in particular the perennial causes the environmental degradation, and the pastoral value reduction that is independent of biodiversity. Temporal dynamics of the forest landscape composition of the reserve showed an opening of the landscape characterized by an expansion of arable land in the transition zone to the protected area of the reserve, the decrease in savanna area and gradual transformation landscape in shrubby savanna.
An extension of our study approach in the Badinko and Kongosambougou reserves could help establishing a monitoring of the spatial and temporal vegetation evolution and putting the rational politics bases of Baoulé biosphere reserve conservation.
Key words: Anthropisation, geomorphology, floristic diversity, Fina reserve, spatial dynamics, Mali.
Doctorat en Sciences agronomiques et ingénierie biologique
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Landman, Leanne. "Restoring Shalom in the economy". Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51899.
Resumo:
Thesis (MA)--Stellenbosch University, 2000.ENGLISH ABSTRACT: This thesis investigates why human poverty and environmental degradation still exist to the extent that they do in a world where there appears to be sufficient scientific and social knowledge to reduce them considerably. It asserts that the reason they continue to exist on such a large scale is because their root cause - a mistaken understanding of humanity's role in creation - has not been sufficiently examined. Humanity's mistaken understanding of ourselves as the Cartesian lords of creation is addressed by introducing the Biblically-based concept of Shalom, as interpreted by theologians Ulrich Duchrow and Gerhard Liedke in their book, Shalom. Biblical Perspectives on Creation, Justice and Peace (1987). The concept stresses how our exploitative relationship towards creation results in destructive relationships with our fellow human beings and ultimately with God. The thesis argues that global capitalism's central value of accumulating wealth for its own sake has severely disrupted Shalom in society and the rest of creation. Using a second work of theologian Ulrich Duchrow, Alternatives to Global Capitalism. Drawn from Biblical History Designed for Political Action (1995), the social and environmental poverty inducing structures within the world economy are highlighted. It is asserted that in order to reduce poverty and environmental degradation within the economy, this central value of wealth accumulation for its own sake has to be replaced with one that seeks to satisfy the basic needs of all people. The thesis also discusses the inability of the South African government's macro economic strategy - the Growth, Employment and Redistribution plan (GEAR)- to create Shalom. In order for the macro-economic strategy of South Africa to address the exploitative relationships that exist within the economy, it is argued that a more critical attitude towards the values and structures of the market economy is needed.
AFRIKAANSE OPSOMMING: Hierdie tesis ondersoek die vraag hoekom armoede en omgewingsaftakeling steeds bestaan in 'n wêreld waar genoegsame wetenskaplike en sosiale kennis beskikbaar is om dit aansienlik te verminder. Dit argumenteer dat die rede waarom hierdie probleme op so 'n groot skaal voortbestaan, is omdat hulle grondoorsaak - 'n verkeerde verstaan van die mens se rol in die skepping - nie voldoende ondersoek is nie. Die mensdom se misverstaan van sigself as die Cartesiaanse meesters van die skepping word aangespreek deur die ondersoek van die Bybels-gebasseerde konsep van Shalom, soos geïnterpreteer deur die teoloë Ulrich Duchrow and Gerhard Liedke in hulle boek Shalom. Biblical Perspectives on Creation, Justice and Peace (1987). Die konsep benadruk hoe ons eksploiterende verhouding tot die skepping resulteer in 'n vernietigende verhouding met ons medemens en uiteindelik, met God. Die tesis argumenteer dat globale kapitalisme, met die akkumulasie van welvaart vir sigself as sentrale waarde, Shalom ondermyn in die wêreld en die res van die skepping. Deur gebruik te maak van 'n tweede werk van die teoloog Ulrich Duchrow, Alternatives to Global Capitalism. Drawn from Biblical History Designed for Political Action (1995), word die strukture wat sosiale- en omgewings-armoede veroorsaak binne die wêreldekonomie, ondersoek. Dit word gestel dat, ten einde armoede en omgewingsvernietiging te verminder, hierdie sentrale waarde van welvaartakkumulasie vir sigself vervang moet word met een wat daarna streef om die basiese behoeftes van mense te bevredig. Die onvermoë van die Suid-Afrikaanse regering se makro-ekonomiese strategie, naamlik die Groei-, Werkskeppings- en Herverdelingsprogram (GEAR) - om Shalom te skep, word ook bespreek. Dit word geargumenteer dat, ten einde 'n situasie te bereik waar die makro-ekonomiese strategie van Suid Afrika die eksploiterende verhoudings binne die ekonomie aanspreek, 'n meer kritiese houding ten opsigte van die waardes en strukture van die vryemark ekonomie benodig word.
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Hakizimana, Paul. "Analyse de la composition, de la structure spatiale et des ressources végétales naturelles prélevées dans la forêt dense de Kigwena et dans la forêt claire de Rumonge au Burundi". Doctoral thesis, Universite Libre de Bruxelles, 2012. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209727.
Resumo:
Dans cette étude, la composition taxonomique, la structure spatiale et les ressources végétales naturelles prélevées dans les forêts de Kigwena et de Rumonge ont été analysées. Les deux forêts sont situées au Sud-Ouest du Burundi, dans une région de forte densité de population. L’objectif global de l’étude était d’élucider des éléments de l’écologie de la forêt dense de Kigwena et de la forêt claire de Rumonge en vue de leur conservation optimale. Les résultats montrent que les deux forêts sont floristiquement différentes malgré leur proximité géographique. Les types biologiques sont dominés par les phanérophytes, les chaméphytes et les thérophytes ;ce qui traduit des adaptations des espèces aux conditions du milieu de vie forestier caractérisé par un stress hydrique et par d’importantes perturbations d’origine anthropique. Le spectre phytogéographique est en concordance avec la localisation des forêts étudiées dans le territoire phytogéographique du District du Mosso/Malagarazi, caractérisé par la présence des espèces à distribution soudano-zambézienne et des espèces de liaison soudano-zambézienne et guinéo-congolaise. La forêt dense de Kigwena et la forêt claire de Rumonge sont soumises aux mêmes influences phytogéographiques et n’ont donc pas connu d’isolement géographique. Dans la forêt dense de Kigwena, l’hétérogénéité spatiale de la végétation, reflétée par l’existence de quatre groupements végétaux distincts, obéit aux gradients d’humidité et d’anthropisation. Par contre, dans la forêt claire de Rumonge, l’hétérogénéité spatiale de la végétation se traduit par des variations stationnelles dans un même fond floristique. L’analyse de la distribution spatiale a montré que les arbres sont répartis selon le modèle spatial agrégé. Les ressources végétales prélevées dans les deux forêts par les populations riveraines servent en grande partie à des fins médicinales, matérielles, alimentaires, énergétiques et/ou socio-culturelles. Les prélèvements de ces ressources, l’agriculture intensive, l’exploitation des carrières, l’aménagement des infrastructures, les feux de forêt et les chablis ont été identifiés comme étant des facteurs de perturbation qui amplifiaient la dégradation et le risque de disparition des forêts de Kigwena et de Rumonge. En définitive, cette étude a montré que les forêts étudiées ont une richesse taxonomique et une valeur conservatoire considérables. Mais ces forêts sont menacées sous l’action d’une anthropisation croissante. Pour remédier à cette situation, des mesures et des actions de conservation ont été proposées pour un court terme. /The taxonomic composition, the spatial pattern and the botanical resources used by Man around the Kigwena and Rumonge forests were studied. Both forests are located in the south-western part of Burundi, in a zone characterized by a high population density. The overall objective of this study was to understand the ecology of the Kigwena and Rumonge forests in order to support their conservation. Results show that the flora of the two forests are different although their geographical proximity. The life forms are dominated by phanerophytes, chamaephytes and therophytes; this observation corresponds to an adaptation of the floras to water stress and anthropogenic disturbances. The phytogeographical spectrum is directly related to the presence of the forests in the Mosso/Malagarazi District. It is characterized by the presence of species with a soudano-zambezian distribution and by species of the soudano-zambezian/guineo-congolese connexion. No geographical isolation was evidenced which could have altered the composition of the Kigwena and Rumonge forests. In the Kigwena forest, the spatial floristic heterogeneity is shown by four different plant communities which occur according to anthropogenic disturbance and soil moisture gradients. But, in the Rumonge forest, the spatial floristic heterogeneity occurs with more common species, in the same flora. The analysis of the spatial pattern of the trees revealed a general tendency towards a clumped distribution. Many natural plant resources are removed from the Kigwena and Rumonge forests by neighbouring populations for medicinal use, material use, food use, energy use and cultural use. Removal of natural plant resources, intensive agriculture, quarry exploitation, infrastructure development, forest fires and windfall of trees have been identified as disturbance factors which amplify the degradation and the risk of disappearance of the forests of Kigwena and Rumonge. Ultimately, this study shows that the Kigwena and Rumonge forests are characterized by a high taxonomic richness as well as by their importance for conservation. Nevertheless, these forests are threatened by increasing anthropogenic activities. Consequently, short-term measures and actions for conservation are proposed.Doctorat en Sciences
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Thornton, Helen Clare. "State of nature or Eden? : Thomas Hobbes and his contemporaries on the natural condition of human beings". Thesis, University of Hull, 2001. http://hydra.hull.ac.uk/resources/hull:3531.
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Thornton, Helen. "State of nature or Eden ? : Thomas Hobbes and his contemporaries on the natural condition of human beings /". Rochester (N.Y.) : the University of Rochester press, 2005. http://catalogue.bnf.fr/ark:/12148/cb392803907.
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Mama, Adi. "Anthropisation des paysages au Bénin: dynamique, fragmentation et développement agricole". Doctoral thesis, Universite Libre de Bruxelles, 2013. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209532.
Resumo:
RésuméAfin de mieux comprendre l’anthropisation des paysages au Bénin, la dynamique de l’occupation du
sol a été évaluée en zone soudanienne (Nord-Bénin), soudano-guinéenne (Centre-Bénin) et guinéenne (Sud-Bénin) à partir de trois images satellitaires de type Landsat MSS 1972, TM 1986 et ETM+ 2006.
Ces trois zones reflètent assez bien le contexte environnemental et humain de la zone intertropicale.
L’objectif principal de la présente thèse est de quantifier la dynamique paysagère due à l’anthropisation des paysages de forêts-savanes à partir de la télédétection, du système d’information géographique et de l’écologie du paysage.
Nos résultats ont montré que l’équilibre écologique des paysages de forêts-savanes a subi
d’importantes perturbations. L’agriculture itinérante sur brûlis, l’exploitation forestière, la carbonisation, l’urbanisation, les feux de végétation et les plantations ont été identifiés comme les principales forces motrices de ces dynamiques. Les matrices paysagères, qui étaient historiquement constituées de forêts-savanes ont été remplacées par une mosaïque de savanes, de champs-jachères, de sols nus-agglomérations, des plantations forestières et fruitières. L’exploitation des données de télédétection a permis de distinguer 4 grands processus de transformation spatiale des classes d’occupation du sol.
Ainsi, entre 1972 et 2006, les processus dominants dans le paysage ont été la déforestation, la savanisation, le développement agricole marqué par la création suivie de l’agrandissement des taches de champs-jachères.
La quantification des perturbations anthropiques, des indices de la structure spatiale calculés pour
chaque classe d’occupation du sol sur la base de la densité, de l’aire moyenne, de la dominance, de
l’indice de forme et la dimension fractale des taches des classes a permis de détecter un processus global de fragmentation et d’anthropisation des paysages.
Les dynamiques temporelles de la structure et de la composition des paysages de forêts-savanes dans
les 3 zones climatiques du Bénin ont montré une anthropisation illustrée surtout par la fragmentation des forêts-savanes. La simulation des dynamiques à l’horizon 2025 à partir de la chaine de Markov de premier degré a montré que pendant que les champs-jachères, plantations et les sols nus-agglomération s’étendront, les forêts-savanes connaîtrons une forte diminution. En définitive, notre étude a mis en évidence que toutes les trois zones étaient fortement dynamiques. Ces transformations anthropiques vont compromettre dangereusement l’avenir de ces paysages dont dépend la survie des populations locales. Notre approche permet de poser les bases d’une politique rationnelle de conservation et d’aménagement des paysages naturelles en établissant des seuils structuraux minimaux des fragments nécessaires à la préservation de la biodiversité.
Abstract
To understand better the landscape anthropization in Benin, the dynamics of the land use was
estimated in soudanian zone (North-Benin), soudano-Guinean (Centre-Benin) and guinean (south-
Benin) from 3 Landscape satellite images (MSS 1972, TM 1986, and ETM+ 2006), supported by field
visits. These 3 zones reflect well enough the environmental and human context of the intertropical zone. The main objective of the present dissertation was to quantify the landscape dynamics due to the landscapes anthropization of forests-savannahs from the Remote Sensing, Geographic Information System and from Landscape Ecology.
Our results showed that the ecological balance of the forests-savannahs underwent important
disturbances. Slash-and-burn agriculture, logging for timber, carbonization, urbanization, vegetation fire and tree plantations have been identified as the main driving strengths of these dynamics.
The landscape matrix’s, which were historically constituted by forests-savannah, has been substituted by a mosaic of savannah, fields-fallows, grounds nudes-urban area and plantations. The use of Remote Sensing data allowed distinguishing four big spatial transformation processes of the land cover classes.
So, between 1972 and 2006, the dominant processes in the landscape were the deforestation, the
savanization, the agricultural development marked by the creation followed by the enlargement of the
spots of field-fallows. The anthropogical disturbances quantification of the spatial structure indications calculated for every land cover classes on the basis of the density, average area, dominance, shape index and the fractal dimension index of the patches classes allowed detecting a global fragmentation
process and the anthropization of the landscapes.
The temporal dynamics of the structure and composition of the forests-savannahs landscape in the 3 climatic zones area of Benin showed an anthropization illustrated especially by the forest-savannahs fragmentation. The dynamics simulation by 2025 referring to Markov chains of the first degree tendency showed that while fields-fallows, tree plantations and nudes-urban area will extend, forestssavannahs shall know a strong decrease.
After all, our study highlighted that every 3 zones were highly disturbed. These anthropogenic
transformations are dangerously going to compromise the future of these landscapes on which depends the local populations survival.
Our approach allows putting the bases of a rational preservation policy and management natural landscapes by the thresholds establishment of fragments necessary for the biodiversity conservation.
Doctorat en Sciences agronomiques et ingénierie biologique
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McLeman, Robert Andrew. "A management strategy for potential human population movements as a result of climate change". Thesis, Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B14040190.
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Haggarty, Roni Maureen. "Photo/synthesis: photography, pedagogy and place in a northern landscape /". Burnaby B.C. : Simon Fraser University, 2005. http://ir.lib.sfu.ca/handle/1892/2202.
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Pryor, Alexander John Edward. "Humans and the Dansgaard-Oeschger cycles in northern Europe 50,000-20,000ya". Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609906.