Spelling suggestions: "subject:"mountain"" "subject:"fountain""
721 |
Importance des interactions entre plantes et mycorhizes dans le maintien de la productivité des écosystèmes pastoraux montagnards soumis à des forçages climatiques / Plant-fungus interactions in the alpine environment subjected to future climatic conditionsWahl, Anne-Lena 13 June 2016 (has links)
Bien que les champignons mycorhiziens arbusculaires (AMF) soient présents des habitats collinaires aux habitats alpins, les recherches sur leur rôle dans l’écosystème montagnard sont encore incomplètes. Les objectifs de cette thèse sont d’analyser l’écologie et le fonctionnement des AMF ainsi que leur réponse au changement global dans les écosystèmes montagnards. Nous tentons de répondre aux questions de recherche suivantes : quels sont les effets de l’altitude sur les AMF indépendamment des effets des autres gradients et de la relation AMF-plante hôte ? Quelles relations de facilitation se développent dans les écosystèmes montagnards et quels bénéfices les plantes tirent-elles des AMF ?Avec l’augmentation d’un stress environnemental la symbiose AMF-plante doit théoriquement devenir plus mutualiste. Nous émettons l’hypothèse d’une modification du fonctionnement des interactions AMF-plante selon un gradient altitudinal dans les conditions environnementales actuelles, puis dans les conditions futures. Afin de vérifier ces hypothèses, une expérimentation in situ a été mise en place dans les Alpes Centrales d’Italie pour évaluer les variations des taux de mycorhization et leur abondance dans la communauté microbienne du sol, étudier la nature des relations entre plantes et mycorhizes ainsi que la productivité végétale le long d’un gradient altitudinal. De plus, les influences d’une augmentation de la température et d’une réduction des précipitations sont analysées séparément dans une chambre de croissance sous conditions contrôlées, ce qui permet de distinguer leurs effets respectifs sur la productivité des plantes et sur les interactions plantes – mycorhizes.Cette thèse montre que les AMF sont omniprésents dans les écosystèmes de montagne et qu’une diminution de leur abondance avec l'altitude dépend du contexte climatique global. D'autre part, la relation des AMF avec les plantes est fortement dépendante de la plante-hôte, ainsi que du contexte biotique et abiotique. Troisièmement, un changement des interactions AMF-plante avec l'altitude est suggéré par des indices indirects, mais est également très probablement dépendant de l'identité de la plante hôte. Cette thèse propose aussi une nouvelle orientation de recherche pour bien évaluer les hypothèses présentées. Il est nécessaire de réaliser des études sur le terrain où la présence des AMF est contrôlée et les interactions AMF-plante peuvent être évaluées. Afin de généraliser les résultats, ces expérimentations doivent être menées à différentes échelles spatiales et représenter différentes aires géographiques.Il est particulièrement important de comprendre et de qualifier ces processus en zone montagnarde pour prévoir leur évolution possible dans un contexte de changement global. Nos expérimentations montrent en effet que le réchauffement est un facteur important car il aggrave les conditions de sécheresse en basse altitude et entraine une baisse de la productivité des plantes. Nous démontrons que la présence de mycorhizes atténue l’impact du changement climatique sur la productivité des plantes mais que le niveau de cette atténuation varie selon les espèces de plantes.Les connaissances actuelles concernant les AMF en milieu montagnard sont peu développées sur les processus en jeu dans les interactions AMF-plantes. Grâce aux hypothèses présentées et à leur approche expérimentale cette thèse offre de nouvelles perspectives sur l’analyse de ces processus. / Even though arbuscular mycorrhizal fungi (AMF) are present from foothills to all alpine habitats, research on their role in mountain ecosystems remains incomplete. The main objective of this dissertation was to investigate interactions between AMF and plants along altitudinal gradients under both, natural conditions and simulated future climate change conditions.A novel framework is suggested for the functioning of the AMF-plant relationship along altitudinal gradients based on the stress gradient hypothesis. The first hypothesis expects the AMF-relationship to shift along the mutualism–parasitism continuum following changing environmental stress along the altitudinal gradient. The relationship might be most mutualistic at the subalpine zone. In a second hypothesis, this shift along the mutualism-parasitism continuum is predicted to be different under climate change conditions, and the most mutualistic expression of the AMF-plant relationship expected in the montane and alpine zone. Studies to validate the presented hypotheses will help to identify important mechanisms underlying plant-AMF interaction and with that the mediation of plant-plant interactions by AMF. In the scope of this thesis, the framework was addressed in field experiment as well as under controlled conditions in a climate chamber experiment.From a literature review and from a field experiment along a dry inner-alpine altitudinal gradient this thesis proposes the following conclusions: First, AMF are also ubiquitous in mountain ecosystems, but a decrease in their abundance with increasing altitude is dependent on the overall climatic context. Second, their relationship to plants is however strongly dependent on the host plant species as well as the biotic and abiotic context. Third, a shift of the AMF-relationship along with altitude is expected but will quite possibly also depend on the plant species identity. Fourth, to fully assess the suggested working hypotheses for AMF-plant interactions field studies must be conducted at different spatial scales and covering different mountain systems.It is particularly important to understand and investigate the drivers of AMF plant relationship in mountain ecosystems to be able to make sound predictions for AMF-plant interactions under future climate change conditions. The presented field and climate chamber experiments on climate change show that temperature is an important factor because it aggravates the conditions of drought in lowland and a threshold is surpassed. It becomes also clear that whether AMF mitigate climate change effects for plants or not is dependent on the plant species. Altogether this thesis contributes to current research questions in ecology, climate change mitigation and plant–soil interactions, because it addresses the role of AMF in mountain grassland ecosystem, investigates the effects of climate change and provides a new framework concerning the functioning of the AMF-plant relationship ranging from parasitism to mutualism.
|
722 |
Společenstva pancířníků (Acari: Oribatida) přirozeně se vyvíjejících a asanovaných horských smrčin na Šumavě / Communities of oribatid mites (Acari: Oribatida) of naturally regenerating and salvage logged mountain spruce forests of Šumava MtsKOKOŘOVÁ, Petra January 2015 (has links)
The main aim of this study was to describe and compare communities of oribatid mites of selected areas in mountain spruce forests near Březník in the Šumava National Park, where different types of management were used after the spruce dieback caused by bark beetle gradation more than 15 years ago. Naturally regenerating and salvage logged areas were compared. Significant differences were found in the oribatid mite community composition between the areas with different types of used management. The oribatid mite community in naturally regenerating areas was in better shape and its abundance and species composition was similar to the community of a control area in a fully grown healthy spruce forest.
|
723 |
The vegetation ecology of the Witteberg and Dwyka Groups south of Worcester, Western Cape Province, South AfricaLe Roux, Anso 01 1900 (has links)
The vegetation supported by the Witteberg and Dwyka Groups south of
Worcester is a diverse mosaic of fynbos-, renosterveld- and succulent karoo
vegetation units sustained by a winter-rainfall pattern. Elytropappus rhinocerotis
(renosterbos) dominated plant communities are found on finer grained soils
derived from the various mudrock-dominated formations of the Witteberg
Group, a Passerina truncata (gonnabos) dominated shrubland with large Protea
shrubs and / or small Protea trees where the substrate is largely influenced by
the sandstone-dominated formations of the Witteberg Group, a grass
dominated Capeochloa arundinacea (Olifantgras) shrubland where both
mudrock-dominated and sandstone-dominated formations influence the
substrate as a result of folding, a karoo Hirpicium integrifolium (Haarbossie)
dominated shrubland where succulents are in abundance on the Dwyka tillite,
and a distinct Thamnochortus bachmannii restio-dominated sandveld in areas
where deep aeolian sand had accumulated.
The differences in vegetation communities are mainly based on geology with
consequent soil characters and degree of rockiness, as well as topography,
moisture availability and the water holding capacity of the soil. Although slope,
aspect and elevation can sometimes be associated with specific plant
communities, geology, soil pH and rock cover are the principal elements
responsible for shaping the vegetation mosaic. Rather than a broad ecotone,
the vegetation of the study area is understood as a complex mosaic mountain
vegetation entity. / Environmental Sciences / Ph. D. (Environmental Sciences)
|
724 |
Zemský soud větší 1541 - 1620 (Personální obsazení) / The Superior Land Court 1541 - 1620 (Personnel Overview)Mareš, Petr January 2014 (has links)
The topic of the dissertation is a reconstruction of organisation structure and personnel overview of the Superior Land Court in Bohemia between 1541-1620. The thesis is divided into two parts of the research. In the first part, the court is examined from perspective of administration history and history of justice. The aim is to reconstruct the structure of courts as an independent institution within the organisation of the provincial administration in Bohemia prior to the Battle of White Mountain. Position of court within the structure of noble courts before 1620, as well as the subject of location, time frame and the process of judicial hearing, the topic of casting and seating arrangements or subject of the occupation and release of judicial posts is being dealt with in its sub-chapters. This part is based on normative sources of the central authorities and sources of assessor's personal nature. Judges - as a group of individual assessors within the court are examined in the other part. The aim is to find and identify all personnel appointed for the function within the Court associate justice (the Chief Clerk; Juror without the Superior Land Court). Each juror is presented in structured biography. The biographies are drawn according to a template. The core of biography is mainly to monitor assessor in...
|
725 |
Aspectos biogeográficos e autoecológicos de encraves florestais úmidos no nordeste do Brasil / Biogeographics and autoecologics aspects of humid forests enclaves, Northeastern BrazilDiogo, Ivan Jeferson Sampaio January 2013 (has links)
DIOGO, Ivan Jeferson Sampaio. Aspectos biogeográficos e autoecológicos de encraves florestais úmidos no nordeste do Brasil. 2013. 87 f. Dissertação (Mestrado em ecologia e recursos naturais)- Universidade Federal do Ceará, Fortaleza-CE, 2013. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-05-20T18:08:23Z
No. of bitstreams: 1
2013_dis_ijsdiogo.pdf: 1562015 bytes, checksum: 94a9fdf4c149caf413552b026bc16f4f (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-05-27T20:34:15Z (GMT) No. of bitstreams: 1
2013_dis_ijsdiogo.pdf: 1562015 bytes, checksum: 94a9fdf4c149caf413552b026bc16f4f (MD5) / Made available in DSpace on 2016-05-27T20:34:15Z (GMT). No. of bitstreams: 1
2013_dis_ijsdiogo.pdf: 1562015 bytes, checksum: 94a9fdf4c149caf413552b026bc16f4f (MD5)
Previous issue date: 2013 / The origin of vegetation found in the brejos nordestinos is linked to climatic variations that occurred during the Pleistocene, which facilitated the entry of species of Amazonian and Atlantic forests in semiarid areas. The dispersal and pollination are present evidence of the evolutionary process that led to the refuge for certain species. The present study examined the contribution of the number of species of Amazon and Atlantic Forest, Caatinga and Mountain Forests of Northeast to the floristic composition of Baturité mountain range, determining the dispersal and pollinating syndromes. The sharing of species between areas indicates the existence of adequate environmental conditions during the late Pleistocene to allow the exchange between the Amazon and Atlantic floras, creating transition environments or ecotones in moist mountain forests of the Northeast. The environmental predictors zoochory and soil organic carbon along with their associated ecological processes determine the distribution of species in the moist forests and hence the ecological niche. Baturité presents most species melittophilous and dispersed by animals, which differ between woody and non-woody components of vegetation, altitude and slope found. / A origem da vegetação encontrada nos brejos de altitude nordestinos está associada às variações climáticas ocorridas durante o Pleistoceno, que facilitaram a entrada de espécies das florestas Atlântica e Amazônica no domínio semiárido. A dispersão e a polinização são atuais provas do processo evolutivo que levou ao refúgio de determinadas espécies. O presente trabalho verificou o número de espécies das Florestas Amazônica e Atlântica, Caatinga e outros Brejos de Altitudes nordestinos presentes na composição florística da Serra de Baturité, determinando as síndromes de dispersão e de polinização da flora do remanescente. O compartilhamento de espécies entre os domínios indica que houve condições ambientais adequadas durante o Pleistoceno tardio para permitir o intercâmbio entre as floras Amazônica e Atlântica, gerando ambientes de transição ou ecótonos nas florestas serranas úmidas do Nordeste. Os preditores ambientais zoocoria e carbono orgânico do solo juntamente com seus processos ecológicos associados determinam a distribuição de espécies nos brejos de altitude e consequentemente o nicho ecológico. A Serra de Baturité apresenta a maioria das espécies melitófilas e dispersas por animais, que diferem entre os componentes lenhoso e não lenhoso da vegetação, a altitude e a vertente encontrada.
|
726 |
Intervenções das políticas federais de educação nos sistemas públicos municipais de ensino: reflexos na Região Serrana do Estado do Rio de Janeiro (1996-2006) / Intervention of Federal Education Policies in Public Municipal System of Teaching: reflections in the mountain region of the Rio de Janeiro State (1996-2006)Roberto Faria 14 December 2010 (has links)
Ao longo dos anos 1990, a partir da Constituição Federal de 1988, da Emenda Constitucional n 14 e da LDB, ambas de 1996, novo panorama educacional tomou forma no Brasil, causando impactos, principalmente no meio rural. Naquele momento, se redefiniram as responsabilidades de estados e municípios na oferta da educação escolar, instituíram-se mecanismos de colaboração, financiamento, e manutenção entre as três esferas, reforçando-se o papel da União, como coordenadora das políticas em âmbito nacional. Considerado pelo Governo Federal como a principal reforma educacional promovida pelo Brasil na década de 90, o Fundo Nacional de Desenvolvimento do Ensino Fundamental (FUNDEF) assegurava a redistribuição dos recursos públicos, vinculados ao ensino obrigatório, de acordo com o número de alunos atendidos pela rede municipal e estadual de ensino,baseado no custo- aluno anual. Ao mesmo tempo, através do Fundo Nacional de Desenvolvimento da Educação(FNDE), a União exerce sua função supletiva e redistributiva em relação à escolaridade obrigatória. A investigação tem ainda como objetivo, desvelar algumas contradições; a regulamentação do FUNDEF implicou em perda ou aumento da receita; enquanto, nos programas no FNDE, os gastos com os recursos públicos deveriam ser controlados pelos diversos conselhos de fiscalização e acompanhamento (CACS). Por outro lado, em alguns municípios do interior, o critério para a escolha dos integrantes destes conselhos e dos próprios secretários de educação, se revela como de cunho pessoal, priorizando a execução das formalidades burocráticas. Perante tal cultura política, o cumprimento da nova legislação, gerou dificuldades de ordem político-administrativa, no sentido de assumir as exigências daquelas novas diretrizes. O estudo sobre os sistemas públicos de ensino da Região Serrana (RJ) se baseou na metodologia do estudo de caso, na revisão de literatura sobre o tema e também, em dados oficiais e entrevistas com os dirigentes das secretarias municipais de educação de Santa Maria Madalena, Trajano de Moraes e São Sebastião do Alto. / Along the 90s, from 1988 Federal Constitution, n 14 Constitutional Amendment and from LDB, both from 1996, a new educational panorama took place in Brazil, causing impacts, principally in rural area. In that moment, it redefined the responsibilities of States and Municipalities in the provision of school education; it instituted a mechanism of cooperation, supporting and maintenance among the three spheres, reinforcing the Unions role, as a coordinator of the policies nationwide. Considered by the Federal Government as the major reform promoted by the country in decade of the 90s , the National Fund for Primary Education Development (FUNDEF) assured the redistribution of the public resources, attached to the compulsory education, according to the number of the students attended by the Municipal and State education network, based on the annual student-cost. At the same time, through the National Development Fund of Education (FNDE), the Union exerts its supplementary e redistributive function related to the compulsory scholarity.The investigation still has as objective, to unveil some contradictions; the FUNDEF regulation implied in the loss or increase of the income; while, in the FNDE programs, the expenses with the public resources should be controlled by several supervision and monitoring councils (CACS). On the other hand, in some municipalities of the interior, the criterion to the choice of the integrants of these councils and the proper secretaries of education turns out itself to the personal nature, prioritizing the execution of the bureaucratic formalities. Before such political culture, the accomplishment of the new legislation, generated political-administrative difficulties in the sense of assume the requirements of those new guidelines. The study about the public systems of teaching in Mountain Region (RJ) based itself in the methodology of case study, in the literature review about the theme, official data and interviews with the directors of the Municipal secretary of education from Santa Maria Madalena, Trajano de Moraes e São Sebastião do Alto.
|
727 |
Florística e fitossociologia da Floresta Atlântica montana no Parque Estadual da Ilha Grande, RJ / Floristic and phytosociology of montaneLilian Prado Gomes da Rosa 25 February 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este estudo tem por objetivo ampliar o conhecimento sobre a flora da Ilha
Grande, Angra dos Reis, RJ, através da avaliação florística e fitossociológica da
comunidade arbustivoarbórea, com Circunferência à Altura do Peito ≥ 15,7 cm
(CAP ≥ 5,0 cm) em trechos de Floresta Atlântica montana. Foram alocadas 34
parcelas retangulares e permanentes de 10x30 m, totalizando uma área amostral de
1,02 ha. Foram amostrados todos os indivíduos arbustivoarbóreos vivos, que
tiveram aferidas a circunferência do caule, estimada a altura total, altura do fuste e
realizada a coleta de material botânico. A identificação dos espécimes foi realizada
através da análise das estruturas vegetativas e reprodutivas, comparação em
herbários, consultas a literatura especializada e, quando possível, com auxílio de
especialistas. O material botânico coletado está sendo incorporado à coleção do
Herbário da Universidade do Estado do Rio de Janeiro (HRJ). Procedeu-se a
avaliação do status de conservação das espécies determinadas para identificar o
grau de ameaça. A estrutura da comunidade inventaria foi analisada através do
pacote estatístico FITOPAC 2.1. Inventariou-se 1.847 indivíduos arbustivo-arbóreos
vivos, subordinados a 225 espécies ou morfo-espécies de 27 gêneros e 53 famílias
botânicas. Este estudo constatou que a Ilha Grande é uma nova área de ocorrência
para 53 espécies fanerogâmicas. As famílias mais abundantes foram: Myrtaceae
(391 indivíduos), Rubiaceae (337), Euphorbiaceae (100), Fabaceae (84) e
Sapotaceae (72). Myrtaceae (69 spp.), Rubiaceae (14), Fabaceae (13), Lauraceae e
Sapotaceae (11) foram as famílias que apresentaram as maiores riquezas. O índice
de diversidade de Shannon & Weaver (H) obtido foi de 4,609 nats/indvs. e o de
equabilidade (J) de 0,851. Os parâmetros fitossociológicos calculados indicaram que
Amaioua intermedia Mart. (5,17%), Eriotheca pentaphylla (Vell.) A. Robyns (4,84%),
Qualea glaziovii Warm. (2,74%), Vochysia bifalcata Warm. (2,69%), Xylopia
brasiliensis Spreng. (2,48%), Heisteria silvianii Schwacke (2,43%), Coussarea
nodosa (Benth.) Müll. Arg. (2,38%), Guapira opposita (Vell.) Reitz (2,37%), Manilkara
subsericea (Mart.) Dubard (2,02%) e Inga lanceifolia Benth. (1,86%) são as espécies
com maiores Valores de Importância (VI). Entre as táxons inventariados foi possível
identificar 69 espécies raras, representadas na comunidade por um único indivíduo,
e nove espécies com problemas de conservação, dais quais Chrysophyllum
flexuosum Mart., Micropholis crassipedicellata (Mart. & Eichler ex Miq.) Pierre e
Manilkara subsericea (Mart.) Dubard estão categorizadas como dependentes de
conservação; Eugenia prasina O. Berg como vulnerável; Myrceugenia myrcioides
(Cambess.) O.Berg como futuramente ameaçada de extinção; Ocotea odorifera
Rohwer como ameaçada de extinção e/ou vulnerável a extinção; Pradosia
kuhlmannii Toledo como ameaçada de extinção; Solanum carautae Carvalho como
espécie rara e Urbanodendron bahiense (Meisn.) Rohwer em perigo de extinção. A
distribuição dos indivíduos em classes diamétricas apresentou uma tendência
exponencial negativa, sugerindo que a comunidade possui capacidade de autoregeneração.
Os resultados da composição florística e da estrutura da vegetação
montana do PEIG evidenciaram expressiva riqueza e diversidade de espécies
arbóreas, cuja preservação é fundamental para o funcionamento e o equilíbrio desta
formação.
Palavras-chave: Mata Atlântica. Floresta montana. Fitossociologia. Parque Estadual
da Ilha Grande. / The aim of this study is to broaden the knowledge of the flora of the Ilha
Grande in Angra dos Reis, RJ, through the floristic and phytosociological
assessment of the shrub-tree community, with circumferences at breast-height ≥ 15,7
cm (CAP ≥ 15,7cm) in mountain areas of the Atlantic Forest. 34 rectangular plots of
land were assigned and permanent ones of 10X30 m, totaling a surveyed area of
1.02 hectares. All the live shrub-tree were sampled which had the trunk
circumference gauged, as well as estimated total height and the collection of
botanical material was done. The identification of specimen was done through the
analysis of vegetative and reproductive structures, the herbarious comparisons and
the consultations of specialized literature, and whenever possible with the help of
specialists. The collected material is being incorporated into the Rio de Janeiro
University Herbarium (HRJ). The assessment proceeded on the status of the
determined species conservation in order to identify the degree of threat. The
structured of the sampled community was analyzed through the statistic packet
FITOPAC 2.1. 847 individual live shrub-trees were sampled, subordinate to 225
species or morph-species of 27 genus and 53 botanical families. This study found
that the Big Island is a new area of occurrence for 53 species phanerogams. The
most abundant families were: Myrtaceae, (391individuals), Rubiaceae (337),
Euphorbiaceae (100), Fabaceae (84) e Sapotaceae (72). Myrtaceae (69 species),
Rubiaceae (14), Fabaceae (13), Lauraceae and Sapotaceae (11) were the families
which present more wealth. The diversity index of Shannon & Weaver (H) obtained
was that of 4,609 nat/indvs and that of equability (J) of 0,851. The calculated
phytosociological parameters indicated that the Amaioa intermedia Mart, (5,17%),
Eriotheca pentaphylla (Vell.) A. Robyns (4,84%), Qualea glaziovii Warm. (2,74%),
Vochysia bifalcata Warm. (2,69%), Xylopia brasiliensis Spreng. (2,48%), Heisteria
silvianii Schwacke (2,43%), Coussarea nodosa (Benth.) Müll. Arg. (2,38%), Guapira
opposita (Vell.) Reitz (2,37%), Manilkara subsericea (Mart.) Dubard (2,02%) e Inga
lanceifolia Benth. (1,86%) are the species with the greatest Importance Value (VI).
Amongst the sampled species it was possible to register 69 rare species represented
in the community by one single individual, and nine species have conservation
problems, which Chrysophyllum flexuosum Mart., Micropholis crassipedicellata (Mart.
& Eichler ex Miq.) Pierre e Manilkara subsericea (Mart.) Dubard are categorized as
dependent on conservation, Eugenia prasina O. Berg as vulnerable to extinction,
Myrceugenia myrcioides (Cambess.) O.Berg as threatened by future extinction,
Ocotea odorifera Rohwer as endangered and/or vulnerable to extinction, Pradosia
kuhlmannii Toledo as endangered, Solanum carautae Carvalho as rare specie e
Urbanodendron bahiense (Meisn.) Rohwer as danger of extinction. Diameter
distribution was observed with negative exponential trend, suggesting that the
community has the capacity for self-regeneration. The results of the floristic
composition and structure of vegetation montana PEIG showed expressive richness
and diversity of tree species whose preservation is essential to the functioning and
balance this forest formation.
|
728 |
Influence des indicateurs paysagers et de leur échelle d'intégration sur l'habitat d'une espèce avienne : conséquences sur la modélisation de la qualité d'habitat de la Gélinotte dans une perspective de gestion conservatoire / Modelling habitat suitability of Hazel Grouse (Bonasa Bonasia) in the context of human-induced change in ChartreuseAdra, Walaa 27 November 2012 (has links)
Dans le contexte du changement global et de la perte de la biodiversité, la prise en compte de cette dernière dans la gestion forestière reste encore très générale. Les démarches ne sont pas encore opérationnelles alors que les gestionnaires ont besoin d'outils destinés directement à la planification. Ainsi, il est devenu urgent d'améliorer les approches d'évaluation et de suivi de la biodiversité et de développer un cadre conceptuel à partir des indicateurs biologiques qui puisse servir dans la prise des décisions. Ce travail se repose sur une approche associant l'enjeu de conservation d'une espèce sauvage patrimoniale dans un paysage de montagne à la maîtrise d'une gestion forestière qui détermine la qualité de son habitat. Dans le cadre concret de la gestion forestière d'un Parc Naturel Régional où les enjeux sont multiples (écologiques, économiques, touristiques), les acteurs concernés s'interrogent moins sur le « comment gérer » que sur le « où gérer » ; en d'autres termes, définir les périmètres de bonne qualité d'habitat afin d'optimiser la gestion et à l'échelle optimale. Notre travail est moins de procurer des outils aux gestionnaires que de poser les jalons scientifiques d'une approche holistique inspirée de l'écologie du paysage. Nous partons ainsi de l'hypothèse selon laquelle les variables environnementales ainsi que la structure du paysage influencent la présence d'une espèce indicatrice de la diversité biologique d'un milieu. Dans ce travail nous nous appuyons sur cette hypothèse pour développer une démarche spatialement explicite qui permettrait d'atteindre l'objectif de conservation dans le cadre d'un processus de gestion forestière adaptative, en étudiant le cas de la gélinotte des bois dans le Parc Naturel Régional de Grande Chartreuse. Ce modèle prédictif de l'occurrence de la gélinotte des bois en Chartreuse s'appuie sur des indicateurs environnementaux et paysagers aisément mesurables et spatialisables. Ceci permettra d'établir un diagnostic de la qualité de l'habitat, d'approfondir les connaissances sur les relations entre la structure du paysage et l'espèce à différentes échelles et de déterminer les secteurs d'habitat qui sont les plus appropriés à la gélinotte des bois en zone de montagne. La représentation spatiale de l'hétérogénéité à différentes échelles permet d'envisager de nombreuses applications dans les domaines de la conservation et de la gestion forestière multifonctionnelle. Nos résultats, relevant d'une approche spatialement explicite, valident l'hypothèse selon laquelle la qualité de l'habitat de la gélinotte peut être modélisée avec une précision acceptable uniquement à partir d'indices paysagers, s'ils sont calculés sur la bonne étendue. Ils constituent donc une avancée pour une aide à la gestion, puisqu'ils préfigurent d'un outil permettant la localisation de zones prioritaires sur lesquelles la conservation de la gélinotte peut être optimisée. / In the context of global change and current loss of biodiversity, there is an urgent need to improve spatial approaches for assessing and monitoring biodiversity in order to develop a conceptual framework based on biological indicators that can be used in conservation planning. The problem still remains in terms of decisions and knowledge on where to set appropriate conservation targets. Hence, we need detailed and reliable information about forest landscape structure and composition and methods for estimating this information over the whole spatial domain. This work is based on an approach involving conservation of a patrimonial species in a mountain landscape. The Regional Natural Park in the French sub-Alps, used for this study encounters multiple conflicts (i.e. ecological, economic, tourism pressures). The stakeholders are then very concern on "where to manage" in other words, they need tools to define the perimeter of good quality habitat to optimize management at an optimal scale. Landscape metrics are widely used to explore the spatial heterogeneity of landscapes that influence several species distribution. Few empirical researches have comparatively examined their indicator value for certain species occurrence at different scales. Within the framework of this study we test hypothesis concerning the best scale at which Hazel Grouse respond to the landscape structure. Our aim was to evaluate significant relations between different landscape level indicators and species occurrence and to assess the effects of the extent of the considered landscape on their performance. Results showed that spatial scale affected the performance of the metrics, since Hazel Grouse occurrence was usually better predicted at relatively smaller extents of surrounding landscape. In all, outputs of this work constitute support for forest management, as they provide a methodological framework and indicators for prioritizing areas in terms of habitat quality where species conservation planning can be optimized.
|
729 |
Contribution à l'étude de la dynamique des glaciers rocheux dans les Alpes françaises par interférométrie radar différentielle (D-InSAR) / Detection and quantification of movements by remote sensing (InSAR)in permafrost area.Echelard, Thomas 04 April 2014 (has links)
Les glaciers rocheux sont l'une des expressions visibles du pergélisol de montagne et sont à ce titre l'objet d'études nombreuses et variées depuis plus de 20 ans. Deux principaux thèmes sont actuellement étudiés par la communauté scientifique : i) mieux appréhender les mouvements qui affectent les glaciers rocheux ainsi que les mécanismes qui les régissent et évaluer l'impact des changements atmosphériques globaux sur ces formes périglaciaires. Dans ces travaux de thèse nous proposons de contribuer au premier de ces deux thèmes de recherche en utilisant un des outils offerts par la télédétection, déjà utilisé dans d'autres pays pour l'étude des glaciers rocheux : l'interférométrie radar différentielle (D-InSAR). L'interférométrie radar différentielle (D-InSAR) est une méthode basée sur la mesure de la différence de phase entre deux images radar qui couvrent la même zone à différents intervalles de temps et depuis des orbites quasi-similaires. Déjà été utilisée dans d'autres domaines, notamment en glaciologie, volcanologie et sismologie, cette technique crée des interférogrammes, cartes de la déformation du sol en deux dimensions dans la ligne de visée du satellite, qui permettent de détecter et de quantifier un déplacement de quelques centimètres survenu au sol entre deux acquisitions radar. Des recherches en Suisse ont également montré que cette technique pouvait être utilisée pour semi-quantifier les mouvements de glaciers rocheux sur de vastes secteurs et parfois les quantifier (sous réserve de respecter certains critères lors de la création et l'analyse des interférogrammes). Dans ce travail de thèse, nous avons acquis des images radar provenant des satellites ERS (datant de 1991 à 1995) et TerraSAR-X (datant de l'été 2012) grâce à l'ESA (agence spatiale européenne) et au DLR (Deutschen Zentrums für Luft und Raumfahrt, agence spatiale Allemande) dans le but de créer et d'analyser des interférogrammes dans le secteur des Alpes françaises. Nous nous intéressons principalement à la détection des glaciers rocheux. Les archives des satellites ERS-1 et 2 nous ont permis de travailler à l'échelle de l'ensemble des Alpes françaises avec une résolution moyenne (25m en géométrie sol). Les données provenant de TerraSAR-X (TSX) ont permis des analyses plus fines grâce à une meilleure résolution en géométrie sol (10m). Cependant le secteur d'études s'est restreint à la Haute Maurienne/Haute Tarentaise à cause du coût des données et du temps nécessaire à la création et à l'analyse des interférogrammes. Pour les données ERS, nous avons pris en compte l'ensemble des images disponibles au-dessus des Alpes françaises et choisi celles adaptées pour notre étude. Finalement 9 interférogrammes ont été créés. Pour analyser ces données deux méthodes ont été employées : i) une analyse visuelle par des géomorphologues dans un SIG (aidée par des ortho-images et des données topographiques) ; ii) une évaluation de la pertinence des résultats par l'intermédiaire d'une comparaison entre les résultats D-InSAR et des inventaires de glaciers rocheux existants. Finalement une carte de l'ensemble des glaciers rocheux détectés dans les Alpes françaises a été produite. Les données TSX ont été analysées sensiblement de la même manière. Enfin, une troisième étude s'est concentrée sur le cas peu commun du glacier rocheux « déstabilisé » de Pierre Brune (mouvements > 2m/an). Une reconstitution historique des déplacements a été réalisée à partir d'images optiques d'archive et des données GPS ont été acquises durant l'été 2012 et comparées aux données obtenues par D-InSAR. En nous basant sur ces études aux résolutions d'image et aux échelles spatiales variées, nous proposons une discussion sur la pertinence de l'utilisation de la méthode D-InSAR pour du « monitoring » à moyen et long termes des glaciers rocheux mais également sur les atouts et inconvénients de la méthode. / Rockglaciers are one the visual expressions of mountain permafrost and have been the focus of numerous and various studies in the last two decades. Two main topics are studied by the scientific community: i) better understanding the movements of active rockglaciers and the phenomena that generate those movements; ii) assessing impact of global atmospheric change on these periglacial shapes. Here we propose to contribute to the first topic by using remote sensing method of displacement measurements already used in other countries for rockglaciers studies: Differential Interferometric Synthetic Aperture Radar (D-InSAR). D-InSAR is a method of measurement based on the phase difference between two radar images, which represent the same area but at different time intervals. The technique generates interferograms, maps of surface deformation in two-dimensions allowing for the detection and quantification (in centimeters) of variations in distance between the target and the radar between two different data acquisitions. Recent research has shown that the InSAR technique can be used to semi-quantify rockglacier deformation (under the assumption that certain conditions are respected with regard to generating and interpreting the interferograms). In the present thesis, ERS radar images (dating from 1991 to 1995) and TerraSAR-X data (dating from summer 2012) were obtained in courtesy of ESA (European Space Agency) and DLR (Deutschen Zentrums für Luft- und Raumfahrt, German Space Agency) with the aim of generating interferograms. We are interested by the detection of rockglacier movements. The ERS archives allowed us to work at French Alps scale with moderate resolution (25m in ground geometry) whereas TerraSAR-X data have better ground resolution (10m) but our analysis are more local (Haute Maurienne/Haute Tarentaise) due to the cost of the data and the time-consuming nature of the analyzes. With ERS, we selected all archives data and chose the more relevant of them. Finally 9 interferograms were generated. To analyse this amount of data two methods were employed: i) a GIS analysis of interferograms by geomorphologists (helped by ortho-images and topographic data), ii) a comparison between interferograms and existing rockglaciers shape inventory to evaluate the quality of the radar detections. At the end of the analysis a map of the French Alps with all detected rockglacier movements was produced. With TerraSAR-X data, the method of analysis was almost the same. Analyzes focused on the Haute Maurienne/Haute Tarentaise massif. A third scale of analysis is focus on Pierre Brune rockglacier which has been detected on ERS interferograms as destabilized rockglaciers (movement > 2 m/year). Further investigations have been carried out on this site (historical movements reconstitution and GPS acquisitions). Based on these studies with different scales and resolutions, we proposed a discussion about suitability of D-InSAR measurements method for long term rockglaciers monitoring as well as drawbacks and benefits of the method.
|
730 |
Desenvolvimento de microc?psulas contendo as antocianinas presentes no corante do extrato do jambo por polimeriza??o interfacialMaia, Juliana Le?o 08 August 2013 (has links)
Made available in DSpace on 2014-12-17T15:01:33Z (GMT). No. of bitstreams: 1
JulianaLM_DISSERT.pdf: 3337263 bytes, checksum: f1607b1c73a3ec40c4bd82f3a0b43c14 (MD5)
Previous issue date: 2013-08-08 / The industries of food, medicine and cosmetic apply microencapsulation for many
reasons, among them, stabilize the active, control the release of encapsulated and separate
incompatible components of the formulation. In this context, microencapsulation techniques
have been used in the food industry to provide stable liquid and solid ingredients.
Anthocyanins have high antioxidant potential, but they are photodegradable. The challenges
are therefore directed to the research for techniques that could make this potential remaining
active and bioavailable and could be used as a vehicle for the delivery release of bioactive and
micronutrients in appropriate conditions and levels. This work has as main objective to
propose a method to encapsulate the anthocyanins in the extract of mountain apple using the
interfacial polymerization technique. As well as to define the ideal conditions of temperature
and agitation system for this procedure. The microparticles were characterized for size,
morphology, active distribution, surface charge, degradation, composition and stability. The
results, like particle diameter of 5.94 μm and Zeta potential of 7.03 mV, showed that the
technique used to obtain these microparticles was satisfactory and has potential for
application in cosmetics and food / As ind?strias de alimentos, medicamentos e cosm?ticos aplicam a
microencapsula??o por diversas raz?es, dentre elas, estabilizar o ativo, controlar a libera??o
do encapsulado e separar componentes incompat?veis da formula??o. Dentro deste contexto,
as t?cnicas de microencapsula??o t?m sido usadas na ind?stria de alimentos para fornecer
ingredientes l?quidos e s?lidos est?veis. As antocianinas possuem alto potencial antioxidante,
entretanto s?o fotodegrad?veis. Os desafios s?o portanto, direcionados ? busca de t?cnicas que
fa?am com que este potencial permane?a ativo e biodispon?vel para que possa ser usado como
ve?culo para a libera??o de bioativos e micronutrientes, em condi??es e n?veis adequados.
Este trabalho tem como objetivo principal propor uma t?cnica para encapsular as antocianinas
presentes no extrato do jambo vermelho utilizando a t?cnica de polimeriza??o interfacial.
Foram definidas as condi??es ideais de temperatura e agita??o do sistema para o referido
processo. As micropart?culas obtidas foram caracterizadas quanto ao tamanho, morfologia,
distribui??o do ativo, carga superficial, degrada??o, composi??o e estabilidade. Os resultados
obtidos, tal como di?metro de part?cula de 5,94 μm e potencial Zeta de +7,03 mV, mostraram
que a t?cnica utilizada para obten??o destas micropart?culas foi satisfat?ria e possui potencial
para aplica??o na ind?stria de cosm?ticos e alimentos
|
Page generated in 0.2835 seconds