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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.
191

Augaviečių ir mišrinimo įtaka eglės želdiniams VĮ Zarasų miškų urėdijoje / The impact of site type and mixing fo Norway spruce plantations in Zarasai forist enterprice

Račkauskas, Vidmantas 14 January 2009 (has links)
SANTRAUKA Magistro darbe tiriama augaviečių ir želdinių mišrinimo įtaka eglės želdiniams Zarasų miškų urėdijoje. Darbo objektas – paprastosios eglės gryni ir mišrūs želdiniai įveisti 2001 – 2007 m. skirtingose augavietėse VĮ Zarasų miškų urėdijoje. Darbo tikslas – 1) nustatyti augaviečių ir želdinių mišrinimo įtaką eglės želdiniams; 2) įvertinti želdinių kokybę. Darbo rezultatai – atliekant tyrimus nustatyta augaviečių ir želdinių mišrinimo įtaka eglės želdiniams prigijimo ir susivėrimo fazėje ir įvertinta želdinių kokybė. Buvo gauti tokie rezultatai: prigijimo fazėje eglės želdiniai prasčiau auga Nb augavietėje. Jų vidutinis aukštis po trijų vegetacijos periodų lygus 62 cm ir jie 10% žemesni, nei Nc, 27% žemesni nei Lc, 10% žemesni nei Nd, 11% žemesni nei Ld augavietėje. Želdinių prigijimas grynuose želdiniuose Nb augavietėje 89%, Nc – 84%, Lc – 85%, Nd – 95%, Ld – 94%. Želdinių prigijimas mišriuose želdiniuose atitinkamai Nb – 80%, Nc – 83%, Lc – 84%, Nd- 95%, Ld – 94%. 7 metų želdiniams mišrinimas turėjo neigiamos įtakos želdinių prieaugiui į aukštį Nb, Nc, Lc ir Nd augavietėse. Lc augavietėje mišriuose želdiniuose želdinių vidutinis prieaugis buvo 2 cm didesnis, nei grynuose. / RESUME In master,s work is reseach about the influence of habitat and species composition for Norway spruce afforestrations in Zrasai forist enterprise. Objeckt of work – Norwei spruce afforestrations are cultivated in different habitat wich pure and mixed plantations at 2001 – 2007 in Zarasai forist hause. The aim of work – 1) to establish the influence of habitat and species composition for fir afforestations; 2) to appraise the afforestrations quality. Findings of work – in prodress of exces were extalished influens of habitat and composition of species from tahing in phase grow up Nc habitat better than Nb habitat. Thir midlle high were 62 cm and this is 10% higher than Nb habitat after 3 vegetative periods. Afforestrations density 6% and tahing in 5% higher than Lc habitat. The planting of mixced plantations have beed influense in growing Nb, Nc, Lc and Nd habitats. Afforestrations high were 163 cm in Lc habitat was pure plantations and they were 25 cm or 15% higer than mixed plantations. Afforestations hight was 134 cm in Ld habitat was pure plantations and thei were 9 cm or 6% lower than mixed plantations; yearly invument of fir afforestration were 9% and 4% or 2 cm and 1 cm higer in Nc and Lc pure plantations that mixced plantations per 7 vegetative periods.
192

Tręšimo poveikis paprastosios pušies būklei buvusiame Dumsių poligone / Influence of fertilization on the condition of Scots pine plantations in former military range area in Dumsiai

Leonaitis, Edmundas 14 January 2009 (has links)
Darbo tikslas: nustatyti ir palyginti tręšimo mineralinėmis trąšomis, pjuvenų kompostu ir miško kuro pelenais įtaką buvusiame Dumsių kariniame poligone kai kurioms smėlžemių fizikinėms ir cheminės savybėms bei įvertinti ten augančių pušies želdinių būklės ir augimo pagerinimo galimybes. Darbo objektas: smėlžemiuose augantys pušies želdiniai buvusiame Dumsių kariniame poligone; 2001 m. įrengti tręšimo mineralinėmis trąšomis bandymai ir 2005 m. įrengti bandymai, kuriuose kaip trąšos naudoti miško kuro pelenai ir pjuvenų kompostas. Darbo metodai: vizualiai 1 m² dydžio aikštelėse nustatytas dirvožemio žolinės dangos padengimas (%) (kiekviename variante sistemiškai išdėstyta po 5 aikšteles); išmatuotas (n=50) pušų prieaugis į aukštį ir vizualiai nustatytas spyglių pageltimas (dechromacija, %); nustatytas viršutinio mineralinio dirvožemio sluoksnio (0-5 cm; 5-10 cm ir 10-20 cm gyliai, jungtiniai ėminiai iš 20-ies vietų) pHCaCl2 rodiklis ir C, N ir S koncentracijos. Darbo rezultatai: išanalizuoti 2001-2005 metų duomenys; ištirtas tręšimo mineralinėmis trąšomis, pjuvenų kompostu ir miško kuro pelenais poveikis smėlžemių viršutinių horizontų pH rodikliui, C ir N koncentracijoms bei gyvąjai dirvožemio dangai, išanalizuotas ir palygintas pušies želdinių būklės ir augimo pagerėjimas, patręšus skirtingomis trąšomis. / The aim of the study: to determine and compare the influence of the application of the different doses of mineral fertilizers, sawdust compost and wood ash applied in complex with nitrogen on some physical and chemical properties of Arenosols in former military range area in Dumsiai; to evaluate the improvement possibilities of the condition and growth of Scots pine plantations in the area. The object of the study: Scots pine plantations growing on Arenosols in former military range area in Dumsiai; the fertilization trials where the mineral fertilizers were applied in 2001, and the fertilization trials where the sawdust compost and wood ash in complex with N fertilizers were applied in 2005 were further investigated. Methods: the ground vegetation cover (%) was visually assessed in 1 m² plots (5 plots were systematically laid in each treatment); height increment of Scots pine trees (n=50) was measured and discoloration of the needles (%) was visually assessed; mineral topsoil samples from 0-5 cm; 5-10 cm and 10-20 cm depths were collected (each combined sample was taken from 20 places), and chemically analysed for pHCaCl2, C and N concentrations. The results: the data of earlier investigations from the years 2001-2005 were analysed; the influence of the mineral fertilizers, sawdust compost and wood ash treatments on mineral topsoil pH, also the changes of N and C concentrations was analysed; the effects of the ground vegetation cover was assessed; the condition and growth... [to full text]
193

Leaving a bittersweet taste : classifying, cultivating and consuming sugar in seventeenth and eighteenth century British West Indian visual culture

Gobin, Anuradha. January 2007 (has links)
This thesis explores visual representations of British West Indian sugar in relation to the African slave trade practiced during the seventeenth and eighteenth centuries. During this time, sugar played a vital role to the lives of both European and non-Europeans as it was a source of great wealth for many and became transformed into one of the most demanded and widely consumed commodity. From the earliest days of British colonization, the cultivation and production of sugar in the Caribbean has been inextricably linked with the trade in African slaves to provide free labor for plantation owners and planters. This thesis considers how European artists visually represented sugar in its various forms---as an object for botanical study, as landscape and as consumable commodity---and in so doing, constructed specific ideas about the African slave body and the use of African slave labor that reflected personal and imperial agendas and ideologies.
194

Etude de la variabilité génétique et de la plasticité phénotypique de la vulnérabilité à la cavitation chez Fagus sylvatica L.

Wortemann, Rémi 16 December 2011 (has links) (PDF)
Cette thèse visait à étudier la variabilité génétique et plasticité phénotypique de la vulnérabilité à la cavitation chez le hêtre (Fagus sylvatica L.). A cette fin, nous avons tout d'abord testé les variations dues à la méthodologie de mesure de la vulnérabilité à la cavitation. Notre étude a montré que les variations de vulnérabilité à la cavitation au cours du temps sont faibles. Néanmoins, il est préférable d'éviter de récolter les échantillons durant le début de la période de formation du bois. Par ailleurs il est possible de conserver au frais les échantillons sans dégrader les mesures durant au moins un mois. Nos résultats montrent également que la vulnérabilité à la cavitation peut être variable aussi bien au sein d'un même arbre qu'entre populations in situ. Ensuite, nous avons voulu déterminer la part de plasticité phénotypique de la part de variabilité génétique dans la variabilité de la vulnérabilité à la cavitation. Pour cela nous avons étudié 17 populations de hêtre venant de toute l'Europe et poussant dans une plantation comparative. Parmi les 17 populations 6 d'entre elles ont été étudiées dans trois plantations comparatives différentes (France, Espagne et Slovaquie). Nos résultats indiquent que chez le hêtre la vulnérabilité à la cavitation varie considérablement au sein de chaque population. Ils indiquent également que l'on observe peu de différenciation génétique entre populations. Les résultats montrent également que la plasticité phénotypique de la vulnérabilité à la cavitation est importante entre les plantations, et que le degré de cette plasticité peut varier d'une population à l'autre. Pour finir, nous avons regardé s'il existait des relations entre la vulnérabilité à la cavitation et des paramètres d'efficience hydraulique ainsi qu'avec l'efficience d'utilisation de l'eau. Nos résultats ne permettent pas de mettre en évidence des preuves d'un trade-off entre l'efficience et la sureté du xylème.
195

Hacienda La Monserrate : a historic structure report and rehabilitation recommendations

Ayala, Karen M. January 1994 (has links)
For almost 450 years the island of Puerto Rico has had an agricultural economy based on the cultivation and production of sugar. Sugar plantations became small communities within towns with distinctive structures and buildings. When large scale commercial sugar production ceased, plantation houses were abandoned and have deteriorated to the point of collapse. A small number of plantation houses are still standing in defiance of progress and their own deterioration.Plantation houses represent part of Puerto Rico's economic and social history and deserve to be preserved. As a result of their architectural significance and uncertain future, plantation houses throughout the Island, should be documented.The focus of this Creative Project is the documentation of the main house in La Monserrate sugar plantation and present recommendations for its rehabilitation and adaptive reuse. This plantation house is located in Manati, a town along the north coast of Puerto Rico. The document will cover a variety of subjects all related with the history of the development of the sugar industry and its influence in Puerto Rico's architecture. The document includes both, a comprehensive analysis of the house and preliminary recommendations for its future adaptive reuse.It is the author's hope that this document will increase public awareness about the importance of preserving this particular building as well as some of the cultural and economic advantages of historic preservation. The community needs to understand and appreciate their built heritage and restoring and rehabilitating the main house in Hacienda La Monserrate can be the first step to achieve it. / Department of Architecture
196

Pluralisme juridique et dynamiques foncières émergentes à Sabah, Malaysia : paysanneries locales, huile de palme et développement

Profitos, Adrian 01 February 2011 (has links)
La transition agraire à Sabah oppose deux systèmes différents de mettre en valeur le territoire. Le premier se caractérise par l’expansion des plantations de monocultures commerciales alors que le deuxième se caractérise par des petites exploitations familiales qui se basent sur la subsistance et sur la diversification des cultures. Face à ce contraste, le modèle de développement rural proposé par le gouvernement cherche à concilier les intérêts macroéconomiques des grandes plantations avec les intérêts microéconomiques des petites exploitations alors que les premiers ont largement pris l’avantage sur les deuxièmes. En même temps, il existe à Sabah un système juridique foncier caractérisé par le pluralisme juridique. D’un côté nous avons le droit étatique centralisé qui se base sur la codification de la loi et sur la promotion de la propriété privée individuelle alors que de l’autre nous avons un droit coutumier qui se base sur la tradition orale et sur la gestion foncière communautaire. Chaque régime foncier présente une manière distincte de gérer l’accès, l’utilisation et la propriété de la terre et de ses ressources. Le droit étatique soutient l’expansion des grandes plantations alors que le droit coutumier régule la gestion des petites exploitations familiales. Les tensions qui existent entre ces systèmes juridiques différents de mise en valeur du territoire sont à l’origine de ce que nous appelons les dynamiques foncières émergentes. Cette thèse a pour but de mettre en évidence que la manière dont ces dynamiques interagissent, divergent et convergent a des répercussions en termes de développement rural dans la mesure où elles impliquent des tensions sociales et légales ainsi que des stratégies agricoles spécifiques ayant des conséquences économiques particulières. Plus spécifiquement, le but ultime est de comprendre comment le droit foncier coutumier se voit affecté par la transition agraire, comment il interagit par le biais des dynamiques foncières émergentes, et quels sont ses espaces et ses possibilités d’adaptation face à l’expansion d’un modèle de développement rural qui se base sur la modernisation et la marchandisation de l’agriculture.
197

Impacts of climate, topography, and weathering profile on vadose zone hydrology and coastal pine plantation management : a multi-scale investigation, Southeast Queensland, Australia

Wang, Qing January 2008 (has links)
Exotic pine plantations are a major landuse within the coastal lowlands of southeast Queensland, extending from close to the shoreline to the hinterland ranges. These plantations are within a sub-tropical climatic zone, and in most years, the summers are appreciably wetter than the winters. This terrain, in general, has been highly weathered and the soils are poor in nutrients. Environmental factors such as the climate, topography and weathering profile (including soil) are found to be important controls on vadose zone hydrology, which, in turn, has a great impact on tree growth and consequently on the design of management practices. This research project takes a holistic approach to investigate the influence of these environmental factors at different scales, and is designed to fulfil the following objectives: (1) To build a spatial model of forest productivity for the entire Tuan Toolara State Forest (TTSF), southeast Queensland, by analysing the spatial patterns of many environmental variables that may have controls on soil water distribution. (2) To determine how some of these environmental factors are responsible for the development of water-logging and soil salinisation by examining in detail an area of low site index that is severely affected by these two processes. (3) To develop a model to assess the risks of water-logging spatially and temporally. A multiple regression model was constructed to predict the forest productivity (measured by the value of site index, the average dominant tree height at 25 years of age). The independent variables were derived from a digital elevation model (elevation, slope, curvature, hillshade, flow accumulation and distance to streams), γ-ray spectrometry (potassium, thorium and uranium), and interpolated rainfall. The model explained up to 60% of the variance in the site indices and produced predictive maps of site index for two species: P. elliottii Engelm. and Queensland hybrid, a P. elliottii × P. caribaea Morelet hybrid. The model also identified the lowest site index area at the northern Tuan State Forest (NTSF), likely due to a greater risk of water-logging and salinisation. The NTSF area is of low relief and, therefore, the focus has been on the vertical controls of deep weathering profile. The methodology included setting up a network of groundwater bores screened at different depths within the weathering profile, characterising the profile (mineralogy, EC, and pH) and the groundwaters within it (water levels, physico-chemical parameters, major and minor ions). It is found that water-logging is caused by perched groundwater formed on top of the ferricrete or mottled saprolite after prolonged rainfall. Localised salinisation is related to the discharge of brackish groundwater occurring within the mottled saprolite. The deep aquifer within the coarse saprolite is fresh and not responsible for salinisation, a situation that differs from many other settings in Australia. The ability of using the Soil and Water Assessment Tool (SWAT) computer model to simulate soil water balance and to assess the risks of water-logging was tested in a selected catchment in the TTSF. The model successfully simulated stream flow at 2 weirs for a period of 6 years; the achieved R2 were 0.752 and 0.858, respectively. Long-term simulation for a 30-year period showed that there are pronounced seasonal patterns in rainfall and evapotranspiration as well as in soil water. For mature plantation with slopes of 3-15%, the mean annual duration of water-logging ranged from 161 days in the humus podzols, to 110 days in the gleyed podzolic, and to 90 days in the yellow podzolics. The outcomes of this research suggest that forest management can be strongly supported by understanding the impacts of these environmental factors (e.g. climate, topography and weathering profile) on vadose zone hydrological processes; the selection of optimum approach will depend on the research objective or purpose. The models and analytical tools that were developed or tested here have the potential to be successfully applied elsewhere if the input data are available.
198

Impact of exotic tree plantations on carbon and nutrient dynamics in abandoned farmland soils of southwestern Ethiopia /

Lemma, Bekele, January 2006 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2006. / Härtill 4 uppsatser.
199

Plantation systems, land tenure and labor supply an historical analysis of the Brazilian case with a contemporary study of the cacao regions of Bahia, Brazil /

Rezende, Gervásio Castro de, January 1900 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1976. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 322-339).
200

Atributos microbianos e químicos do solo e da serapilheira em plantios puros e mistos de Eucalyptus grandis e Acacia mangium / Soil and litter microbial and chemical attributes in monoculture and intercropped plantations of the Eucalyptus grandis and Acacia mangium

Daniel Bini 20 February 2013 (has links)
Plantios mistos de eucalipto com leguminosas arbóreas vêm sendo estabelecidos a fim de aumentar os teores de nutriente no solo, e estimular a ciclagem biogeoquímica. Para tanto, este trabalho teve como objetivo avaliar alguns atributos microbianos e químicos do solo e serapilheira dos primeiros 20 meses de crescimento de uma segunda rotação de plantios puros e mistos de E. grandis e A. mangium. Foram coletadas amostras de solo e raízes (profundidade de 0-10 cm) e serapilheira aos 2, 7, 14 e 20 meses após o plantio dos seguintes tratamentos: monoculturas de A. mangium e E. grandis sem fertilização nitrogenada, monocultura de E. grandis fertilizado com N e plantio misto entre E. grandis e A. mangium (50E:50A). Dentre os atributos microbianos e bioquímicos do solo foram avaliados o C e N da biomassa microbiana, respiração basal, a atividade das enzimas desidrogenase, celulase, urease, fosfatase ácida, fosfatase alcalina, número de esporos e taxa de colonização de fungos micorrízicos arbusculares. Os atributos químicos do solo avaliados foram: C e N total do solo, P disponível, pH e umidade. Na serapilheira foram avaliadas as concentrações de C, N e P total. As informações obtidas revelaram que houve um efeito cumulativo recorrente da primeira rotação, principalmente na área plantada com A. mangium. Foi possível verificar que no inicio dos plantios florestais os teores de C e N total e P disponível no solo não se alteram drasticamente. Em contrapartida, os conteúdos totais desses elementos na serapilheira são extremamente dinâmicos, dissimilares entre os tratamentos e altamente relacionados com os atributos microbianos e bioquímicos do solo. A. mangium apresentou uma serapilheira com menor relação C/N e C/P, e essa característica se manteve quando ela foi planta com E. grandis, que também apresentou diminuição da relação C/N e C/P da serapilheira. Isso pode ter ocorrido em função ao estimulo da microbiota do solo, sobretudo das fosfatases e pela associação com das plantas com fungos micorrízicos arbusculares. Neste caso, presume-se que a A. mangium é a grande responsável por favorecer a maior atividade microbiana e colonização de FMA em E. grandis no plantio misto quando comparado com os plantios puros de E. grandis. As fosfatases ácida e alcalina foram os atributos microbianos que mais se alteraram com o desenvolvimento vegetal, mostrando a sensibilidade dessa variável aos sistemas de plantio. Estes resultados são informações importantes não apenas sobre a capacidade do plantio misto de E. grandis e A. mangium em maximizar a ciclagem de N e P, mas também sobre o conhecimento da dinâmica desses elementos e da microbiota do solo no inicio dos plantios florestais, fato este pouco abordado pela literatura. / Intercropped plantation between leguminous and eucalyptus has been establishment to increase soil nutrients content and stimulate the biogeochemistry cycling. This work aim evaluated some microbial and chemistry attributes of soil and litter in the early stages of the second rotation of mixed and pure plantations of E. grandis and A. mangium. Soil and roots samples (at 0-10 cm depth) and litter samples were collected at two, seven, 14, and 20 months after planting in the following treatments: monocultures of A. mangium and E. grandis, a monoculture of E. grandis with N-fertilizer, and an intercropped plantation with E. grandis and A. mangium (50E:50A). The intercropped plantation area was subdivided and soil samples collected around of the A. mangium and E. grandis individuals in order to compare the rhizosphere effects of each tree species within this treatment. The microbial and biochemistry attributes measured were: microbial biomass C and N, microbial respiration, metabolic quotient (qCO2), metabolic microbial, enzymatic activity (dehydrogenase, cellulase, urease, acid phosphatase and alkali phosphatase), spore diversity and density and root colonization by arbuscular mycorrhizal fungi. The chemistry soil attributes evaluated were: Total C, total N, available P, pH and moisture. Total C, N and P litter were evaluated. There was a cumulative effect due the first rotation, mainly at A. mangium monoculture. Soil chemistry attributes (total C, total N and available P) were little altered in early stage of the plantations. However, litter attributes were extremely dynamics, dissimilar between treatments and correlated with the soil microbial attributes. A. mangium showed decrease of the litter C/N and C/P ratios (pure and intercropped plantation). In this case, E. grandis also decrease the litter C/N and C/P ratios when planted with A. mangium. Intercropped plantation stimulated the microbial activity, mainly the phosphatases and root colonization by arbuscular mycorrhizal fungi. Thus, presumably A. mangium is the greater responsible to stimulate the soil microbial community in intercropped plantation, favoring E. grandis. Alkali and acid phosphatase were microbial attributes more drastically altered with plant development, showing the sensibility these variables. These results are important information not only about to intercropped plantation capacity for maximize N and P cycling, but also about the knowledge of the dynamic of these elements and the soil microbial in early stages of the forestry plantations, which is little reported to literature.

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