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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

Remote Sensing of Woodland Structure and Composition in the Sudano-Sahelian zone : Application of WorldView-2 and Landsat 8

Karlson, Martin January 2015 (has links)
Woodlands constitute the subsistence base of the majority of people in the Sudano-Sahelian zone (SSZ), but low availability of in situ data on vegetation structure and composition hampers research and monitoring. This thesis explores the utility of remote sensing for mapping and analysing vegetation, primarily trees, in the SSZ. A comprehensive literature review was first conducted to describe how the application of remote sensing has developed in the SSZ between 1975 and 2014, and to identify important research gaps. Based on the gaps identified in the literature review, the capabilities of two new satellite systems (WorldView-2 and Landsat 8) for mapping woodland structure and composition were tested in an area in central Burkina Faso. The results shows that WorldView-2 represents a useful data source for mapping individual trees: 85.4% of the reference trees were detected in the WorldView-2 data and tree crown area was estimate with an average error of 45.6%. In addition, WorldView-2 data produced high classification accuracies for five locally important tree species. The highest overall classification accuracy (82.4%) was produced using multi-temporal WorldView-2 data. Landsat 8 data proved more suitable for mapping tree canopy cover as compared to aboveground biomass in the woodland landscape. Tree canopy cover and aboveground biomass was predicted with 41% and 66% root mean square error, respectively, at pixel level. This thesis demonstrates the potential of easily accessible data from two satellite systems for mapping important tree attributes in woodland areas, and discusses how the usefulness of remote sensing for analyzing vegetation can be further enhanced in the SSZ. / Merparten av befolkningen i Sudano-Sahel zonen (SSZ) är beroende av naturresurser och ekosystemtjänster från woodlands (öppen torrskog) för att säkra sin försörjning. Tillgången av fältmätningar av vegetationens struktur och sammansättning är mycket låg i detta område, vilket utgör ett problem för forskning och miljöövervakning. Denna avhandling undersöker nyttan av fjärranalys för att kartlägga och analysera vegetation, främst träd, i SSZ. En omfattande litteraturöversikt genomfördes först för att undersöka hur tillämpningen av fjärranalys har utvecklats i SSZ mellan 1975 och 2014, samt att identifiera viktiga forskningsluckor. Några av de luckor som konstaterades i litteraturgenomgången låg till grund för de följande studierna där två nya satellitsystem (Worldview-2 och Landsat 8) utvärderades för deras användbarhet att kartlägga trädtäckets struktur och artsammansättning i ett woodland-område i centrala Burkina Faso. Resultaten visar att Worldview-2 är en värdefull datakälla för kartering av enskilda träd: 85.4% av referensträden detekterades och trädkronornas storlek uppskattades med ett medelfel av 45.6%. Worldview-2-data producerade även hög klassificeringsnoggrannhet för de fem lokalt viktigaste trädslagen. Den högsta noggrannheten (82.4%) uppnåddes med multi-temporal Worldview-2-data. Landsat 8 data visade sig mer lämpade för kartering av krontäcke, jämfört med biomassa. Medelfelet för karteringen var 41% för krontäcke och 66% för biomassa, på pixelnivå. Avhandlingen visar att lättillgängliga data från två satellitsystem är användbara för kartläggning av viktiga trädattribut i woodlands, samt diskuterar hur nyttan av fjärranalys för vegetationsanalys kan ökas ytterligare i SSZ.
202

Les cultures Laurel et Blackduck en Abitibi-Témiscamingue : portrait d’une transition technologique vers la fin du Sylvicole moyen tardif

Beaulieu, Guyane 12 1900 (has links)
La transition entre le Sylvicole moyen et le Sylvicole supérieur, vers l’an 1000 de notre ère, correspond à un moment de bouleversements technologiques dans le Nord-Est américain. En Abitibi-Témiscamingue, il s’agit d’une transition entre les cultures Laurel orientale et Blackduck orientale. La poterie blackduckienne semble avoir été rapidement adoptée par les groupes laureliens, sans phase transitoire apparente. Ce mémoire s’intéresse aux technologies céramiques employées par les populations des cultures Laurel et Blackduck en Abitibi-Témiscamingue et cherche à comprendre s’il existe de la continuité ou de la discontinuité entre les deux ensembles. Plus précisément, il est question de voir comment se manifeste la transition entre les deux cultures et comment la technologie céramique permet de caractériser cette transition. Pour ce faire, quatre sites ont été sélectionnés de part et d’autre de la ligne de partage des eaux entre : le site Bérubé (DdGt 5), le site du lac Opasatica (DaGt-4), le site Nault (ClGt-2) et le site Léo-Guay (ClGt-3). Les vases laureliens et blackduckiens provenant de ces sites ont fait l’objet d’une analyse visuelle par attributs morphostylistiques et d’une analyse par attributs technologiques selon les données tomodensitométriques fournies par l’Institut national de recherche scientifique Eau-terre-environnement (INRS-ETE), à Québec. Puisque l’utilisation de la tomodensitométrie dans l’analyse technologique de la céramique est plutôt récente, ce mémoire se veut une contribution modeste, mais originale au développement de cette approche. À la lumière des analyses effectuées, la transition technologique s’est opérée plus lentement que la transition morphostylistique. Les potiers auraient graduellement développé un nouveau savoir-faire, par contact et par expérimentation, produisant un vase mieux adapté à la cuisson des aliments. / The transition between the Middle Woodland and Late Woodland periods, towards 1000 CE, corresponds to a moment of technological upheavals in the American Northeast. In Abitibi-Temiscamingue, it takes the form of a transition between the Eastern Laurel and Eastern Blackduck cultures. Blackduck pottery seems to have been quickly adopted by Laurel groups, with no apparent transitional phase. This masters’ thesis relates to the ceramic technologies employed by the populations of Laurel and Blackduck cultures in Abitibi-Temiscamingue and explors the continuity or lack of continuity between the two groups. More precisely, I ask how this transition between two cultures manifests itself and how ceramic technology allows us to characterize this transition. To that end, four sites have been selected on both sides of the watershed divide between: the Bérubé site, (DdGt-5), the lake Opasatica’s site (DaGt-4), the Nault site (ClGt-2) and the Léo-Guay site (ClGt-3). The Laurel and Blackduck vessels originating from these sites were subjected to a visual analysis using morphostylistic attributes and an analysis using technological attributes based on tomodensitometric data supplied by the Institut National de Recherche Scientifique - Eau Terre Environnement (INRS-ETE) research center located in Quebec City. Since the use of tomodensitometry in ceramic technological analysis is rather recent, this thesis seeks to be a modest but original contribution to the development of this approach. Based on our analyses, the technological transition happened more slowly than the morphostylistic transition. The potters would have gradually developed a new craftmanship, by contact and by experimentation, producing vessels better suited to cooking food.
203

Continuité ou discontinuité dans la technologie céramique : une analyse comparative des attributs technologiques entre le Sylvicole moyen tardif et le Sylvicole supérieur ancien

Girard, Jean-Paul 07 1900 (has links)
La transition entre le Sylvicole moyen tardif (500 à 1000 apr. J.-C.) et le Sylvicole supérieur ancien (1000 à 1200 apr. J.-C.) n’est plus un moment obscur pour les archéologues; cependant, il est toujours vrai que bien des questions demeurent sans réponses. Sur le complexe archéologique de Pointe-du-Buisson, situé au sud-ouest de l’Île de Montréal, la question de l’origine des Iroquoiens du Saint-Laurent fait à nouveau couler de l’encre, cette fois par une perspective tournée vers la technologie céramique. Nous savons, ou croyons savoir, que le montage des vases céramiques passe du colombin vers la méthode du battoir et enclume, mais nous ne savons pas si cette transition technologique s’est faite dans la continuité ou dans la discontinuité. Pour y répondre, 106 tessons de bord provenant de la Station-3 et du site Hector-Trudel de la Pointe-du-Buisson furent sélectionnés, dont 56 datant du Sylvicole moyen tardif et appartenant à la Tradition Melocheville, puis 50 du Sylvicole supérieur ancien et appartenant à la Tradition Saint-Maurice, à l’exception de cinq de culture Pickering. L’échantillon fut soumis au CT-Scan afin de produire des images numériques en trois dimensions qui ont ensuite été étudiées à l’aide du logiciel ImageJ FIJI. Grâce à une approche d’analyse par attributs technologiques, avec un accent sur la comparaison entre mes deux groupes et aussi entre mes données et celles de Guyane Beaulieu (2019), diverses variables contenues dans la fabrique céramique ont été étudiées et quantifiées. D’après les résultats obtenus, et à la lumière d’une rétrospection sur le débat plus large entre les théories migratoires et l’archéologie processuelle, la transition technologique dans la production céramique se serait certes produite graduellement, mais pourrait ne pas être le fruit d’un développement sur place sans aucun apport extérieur. Néanmoins, les technologies céramiques que l’on attribue aux Iroquoiens du Sylvicole supérieur ancien ont été clairement héritées de potières du Sylvicole moyen tardif : par conséquent, l’hypothèse migratoire de Snow ne concorde pas avec les résultats de cette étude. / The transition between the late Middle Woodland period (500 – 1000 AD) and the early Late Woodland period (1000 – 1200 AD) is no longer shrouded in mystery for the archaeologist; even so, many unanswered questions remain. For the archaeological complex of Pointe-du-Buisson located to the south-west of Montreal, research is once more tackling the question of the origin of the Northern Iroquoians, this time using a technological perspective of ceramic production. We know that the construction of ceramic vessels using the coiling method was replaced by the paddle-and-anvil during the transition from the Middle to Late Woodland period. What we are less certain of is the pattern of said change: continuous or discontinuous. For this reason, 106 rim sherds from the Station-3 and Hector-Trudel sites ( the Pointe-du-Buisson archaeological complex) were selected, of which 56 belong to the Melocheville Tradition from the late Middle Woodland period, and 50 belong to the St-Maurice Tradition, of which five are actually Pickering, from the early Late Woodland period. The sample was then analyzed by CT-Scan in order to obtain 3D digital images which were later processed and analyzed with the ImageJ FIJI software. With a technological attribute analysis approach, coupled with a focus on a comparison between my two subgroups as well as between my data and those from a previous study by Guyane Beaulieu (2019), diverse variables contained within the fabric of ceramic vessels were studied and quantified. According to the results, and along with a retrospection on the debate between migration theories and the processual archaeology perspectives, the technological transition within ceramic production would appear to have been a gradual process but might not necessarily point to a strict in situ development. It is clear, however, that there is a continuity within the cultural traits of the ceramic technology attributed to the Iroquoians of the Late Woodland Period with those of the previous period, which refutes Snow’s migration hypothesis.
204

Společenstvo motýlů (Lepidoptera) lesního komplexu Loučany u Klatov / Lepidoptera Community of the Woodland Complex Loučany near Klatovy

Rendlová, Veronika January 2016 (has links)
This thesis is focused on faunistic survey of Macrolepidoptera in Loučany (foothills of the Šumava Mts, Czech Republic). The research, involving different capture methods, proceeded from April to November 2015 on given transect and several other habitats. Based on the results (including partial data from 2013 and the last two decades of the 20th century), an inventory of identified species of Macrolepidoptera was made. Altogether 205 species from 16 families were found in Loučany. The most important species are for example the Black-veined White (Aporia crataegi), High Brown Fritillary (Argynnis adippe), Pearl-bordered Fritillary (Boloria euphrosyne), Purple Emperor (Apatura iris), Spruce Carpet (Thera britannica) and Sandy Carpet (Perizoma affinitata). The environmental parameters of experimental sites were noticed during research and the habitat preferences of species were analysed using specialized literature. Altogether 186 species (90,7 % of all identified species) are linked to some kind of woodland habitat. To support present biodiversity of the community of Macrolepidoptera, it is necessary to practice a suitable woodland management, conserving mosaicity and open canopy. Key words: Lepidoptera, species diversity, Czech Republic, Klatovy area, conservation, woodland management
205

Evaluation du rôle des feux de brousse sur la composition, la structure, la phénologie, et la résistance de la végétation des bois de tapia (Uapaca bojeri) du massif d’Ibity, Nouvelle Aire Protégée, en vue de sa gestion durable / Evaluating the role of bush fires on the composition, structure, phenology, and resistance of tapia (Uapaca bojeri) woodland vegetation of Ibity massive, New Protected Area, for its sustainable management

Alvarado, Swanni Tatiana 10 December 2012 (has links)
Aujourd'hui la perte et la transformation des habitats sont les principales menaces qui causent la diminution de la diversité biologique. A Madagascar, 90% des espèces végétales sont endémiques de l’île et la plupart des formations végétales sont actuellement fortement dégradées ou remplacées par des formations secondaires résultant des activités humaines. Le bois de tapia, dominé par l’espèce endémique de Madagascar Uapaca bojeri, est une formation végétale sclérophylle limitée aux Hautes Terres de l’île. Cette formation, adaptée et résistante au régime de feu naturel de la région, est aujourd'hui fragmentée, couvrant une surface équivalente à 132 255 ha au total. Afin d’augmenter la protection du bois de tapia, une nouvelle aire protégée (NAP) a été établie sur le Massif d’Ibity. L’état actuel de la végétation de bois de tapia est le résultat de l’interaction de facteurs comme le type de sol, le climat, les pratiques humaines traditionnelles et le feu. Bien que le feu soit un des phénomènes qui fasse partie de la dynamique de cette végétation, le régime de feu actuel est également une des causes de sa dégradation. L’objectif de cette thèse est donc d’étudier le rôle du feu sur le cycle démographique et certains processus importants pour l’installation et le recrutement. Ainsi, la germination, la phénologie et la résistance des plantules au feu ont été étudiées. Cette recherche montre que le problème actuel du bois de tapia est 1) la réduction de la floraison et de la fructification par les fréquences de feu élevées ; 2) la réduction du pourcentage de germination après l’exposition des graines à de hautes températures, et 3) la mortalité élevée des plantules après le passage d’un feu, en particulier quand la quantité de combustible est élevée. Ainsi l’installation et le recrutement des espèces ligneuses sont limités par le feu, qui a un effet négatif sur la régénération naturelle. La gestion du feu autour de l’aire protégée est ainsi nécessaire pour sa conservation / Currently loss and transformation of habitats are the main threats which cause the decrease of biological diversity. In Madagascar, 90% of plants species are endemic of the island and most of the plant formations types are at present strongly degraded or replaced by secondary formations resulting from human activities. Tapia woodland, dominated by the endemic tree Uapaca bojeri, is a sclerophyllous vegetation type limited in the Malagasy highlands. This vegetation type, adapted and resistant to the natural fire regime, is very fragmented today, covering a surface equivalent to 132 255ha on the island. In order to increase the protection of tapia woodland, a new protected area was established on Ibity massif. The current state of the woody vegetation is the result of the interaction of some factors as soil type, climate, human traditional practices and fire. Although fire is one of the phenomena that determine the dynamics of this vegetation, the current fire regime is also one of the main causes of degradation. The objective of this thesis is to study the role of fire on the demographic cycle and on some main processes for installation and recruitment. Thus, germination, plant phenology and seedlings resistance after burnt were studied. This research shows that the current problem of tapia woodland are 1) the reduction of flowering and fruiting by high fire frequencies; 2) the reduction of germination percent after seed exposure with high temperatures, and 3) high seedlings mortality after burnt, in particular when the quantity of fuel is raised. Installation and recruitment of woody species are limited by fire, which has a negative effect on natural regeneration. Fire management around the protected area is thus necessary for its conservation
206

Log-diversity and abundance of dead wood dependent bracket fungi and bryophytes, a comparison between spruce woodland key habitats and adjacent production forests in Östergötland, Sweden.

Lundgren Lodetti, Mathilda January 2019 (has links)
Dead wood in forests are essential habitat for a wide range of fungal, insects, lichens and bryophyte species. The main threat to dead wood dependent species is lack of substrate, which aggravates their ability to reach and colonize a new substrate. Inventories of woodland key habitats (WKHs) is a method to map forests with high biological value in Sweden, and these areas may benefit dead wood dependent species. The aim of this study was to compare spruce dominated WKHs with adjacent production spruce forests (APFs), regarding (1) log diversity, (2) log characteristics and (3) abundance of selected species on logs. The study was conducted in Östergötland County in Sweden, seven spruce WKHs (≥ 60% spruce) and seven APFs of three different types (two clear-cuts, two dominated by trees < 20 cm and three dominated by trees > 20 cm) were investigated. Data of eight wood dependent species (three bryophytes and five bracket fungi), log diversity, six log characteristics and two environmental factors were collected. In a total area of 4.27 ha, 210 logs (105 logs in WKH and APF each) were studied and the results show that there were significantly higher amount of coarse logs, distribution area of species, number of logs/ha, diameter, decay class and humidity inside WKHs compared with APFs. The total distribution area of species was approximately 85% larger in WKHs. Bark cover was slightly less in WKHs and sun exposure was significantly higher and humidity was lower in clear-cuts. According to the current study, WKHs are important for conservation of wood depending species due to the higher amount and diversity of coarse dead wood. Furthermore, it is necessary to put aside larger amount of coarse dead wood inside production forests, together with changed logging techniques to increase the suitable substrate for dead wood dependent species.
207

The Analysis of Palaeobotanical Remains from Native American Sites in the Tennessee Region of the Upper Cumberland Plateau.

Beck, Chase W. 13 August 2010 (has links)
Sediment samples were collected from 3 rock shelter sites and one natural pond on the Upper Cumberland Plateau. Samples were processed to quantitatively and qualitatively evaluate pollen and charcoal abundance as well as other palaeobotanicals. The analysis was to determine when prehistoric Native Americans began controlled burns to enhance resources acquisition. Samples were also analyzed for the presence of pollen to determine vegetation changes that may accompany the use of controlled burns and to determine the onset of horticulture. The Upper Cumberland Plateau is often considered a marginal area used only seasonally by Native Americans; however, management practices may have been highly refined to maximize resources acquisition. Results show evidence of overt land management and usage of the area by Native Americans over several thousand years. Remains indicate reliance upon nut producing trees. This reliance led to land management practices designed to maximize availability of said resources.
208

Evaluation of the effects of tree clearing over time on soil properties, pasture composition and productivity

Sangha, Kamaljit Kaur, Kamaljit.kaur@jcu.edu.au January 2003 (has links)
Tree clearing is practised for greater beef production and hence monetary gains from grazing systems of central Queensland. The high rates of clearing in the past and even recently (577, 000 ha/yr during 1999-2001) were mainly to develop land for pastures. The sustainability of cleared pasture systems over the long-term is questioned. Three major types of tree communities i.e. Eucalyptus populnea F. Muell., E. melanophloia F. Muell. and Acacia harpophylla F. Muell. ex. Benth. were selected on one property in central Queensland to quantify the impacts of clearing on pasture production and composition, and soil properties. The impacts were measured over time-since-clearing (recent (&lt5 years), medium (11-13years) and old (&gt30 years)) in unreplicated cleared pastures in comparison to their replicated uncleared/intact woodland pastures of each tree community. Measures of pasture above-ground biomass production on a single property over time-sinceclearing in cleared systems showed that gains were not sustained over the long-term. The difference in response to clearing between tree communities was evident and important to support the future policy decisions. The impact of clearing on soil properties (physicochemical and biological) was confirmed, and explained the lesser availability of nutrients with time of clearing in cleared pastures. The changes in some soil properties underscored the associated risks and changes in ecosystem functions due to clearing. Less litter was produced at cleared than uncleared pastures, but nutrient release was faster at cleared compared to uncleared systems. The overall effect of clearing in terms of pasture and litter production, and major soil parameters were analysed using multivariate analyses.
209

Geophysical Study at Old Stone Fort State Archaeological Park, Manchester, Tennessee

Yerka, Stephen Jay 01 December 2010 (has links)
The Old Stone Fort State Archaeological Park covers over 800 acres within Manchester, Tennessee, and is owned and managed by the Tennessee Division of State Parks. The central archaeological site within the park boundary is The Old Stone Fort mounds that enclose about 50 acres on a plateau above the convergence of the Big Duck and the Little Duck Rivers. The hilltop enclosure dates to the Middle Woodland Period, and radiocarbon dates obtained at the site range from the first to the fifth century A. D. Because of its size and apparent complexity, previous investigations of the site have been quite limited in areal exposure. Many questions remain as to the overall structure of the site, including the relationship of built and natural features, the presence of any structures or other anthropogenic features, and the occurrence of presence of any domestic remains. This research project utilizes detailed digital topographic survey, geographical information system (GIS) analysis, geophysical survey, limited re-excavation of previously investigated portions of the site, and manual coring to locate and characterize archaeological deposits within the enclosure and mounds. Magnetometer, resistance, electromagnetic susceptibility, conductivity, and ground penetrating radar techniques were used during the investigations. Geophysical data, using these instruments, were collected over the same area in many cases. All together 20,000 m2 were examined during the project. Results indicate potential archaeological features and deposits within the plateau interior. Analysis suggests the presence of several geophysical anomalies potentially associated with prehistoric use of the site, especially within the Eastern Gateway complex. One such anomaly, or complex of anomalies, represents a possible structure. Historic archaeological deposits are also indicated by the geophysical data. Excavations at the site were limited to minimize impact. In a re-excavated trench, a lens of black shale within the stone mound construction may indicate a building stage not previously observed at Old Stone Fort. A second excavation confirmed a ditch feature detected in the geophysical survey. Archaeological deposits located during the survey are interpreted as evidence of sustained use of the ceremonial site during the Middle Woodland Period by local corporate groups to maintain and intensify membership for individuals who were settled in nucleated villages throughout most of the year.
210

Middle Woodland Mound Distribution and Ceremonialism in the Apalachicola Valley, Northwest Florida

Frashuer, Anya C. 14 April 2006 (has links)
University of South Florida field investigations in northwest Florida’s Apalachicola Valley have resulted in the relocation of some lost mounds from the Middle Woodland period (ca. A.D. 1 to 650) by trekking through the forest and consulting with avocationals and collectors. This thesis project was triggered by a collector’s donation of some Swift Creek pots and the attempt to relocate the mound from which they came. In the 1970s, Gardner and Nidy recorded this site, named Poplar Springs Mound, categorized as Middle Woodland due to its Swift Creek and Weeden Island pottery. The donated collection contained pottery of the Swift Creek Complicated-Stamped series, Weeden Island series, and a couple of anomalous Mississippian sherds. To see how this mound fit in with other Middle Woodland mounds of the valley, it was necessary to compile data for all of them and relocate as many mounds as possible through additional survey. Artifact types from these mounds, such as pottery, shell, bone, and exotic materials, and burial practices were tabulated and spatial distributions were plotted. The mounds are distributed along the banks of the main navigable waterways of the Apalachicola and Chipola Rivers, on smaller streams and along the Gulf Coast. Nearly all have both Swift Creek and early Weeden Island ceramics, except for three with only Swift Creek types and a single site with only Weeden Island types. The artifact distributions show stone, bone, and shell tools clustering close to the coast and the main waterways. This is also the case for exotic (nonlocal) raw materials and artifacts made from these materials. Copper is distributed mainly along the coast, while other exotics (i.e. mica, galena, hematite) are located along the coast and close to the main rivers. The tabulation of these data, along with the documentation of the Poplar Springs Mound collection, will help archaeologists to see the manifestation of Middle Woodland ceremonial activity in the Apalachicola Valley.

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