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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.
1

Regenera??o natural como indicador de restaura??o florestal em trechos de Floresta Estacional Semidecidual no Espinha?o Meridional, MG. / Natural regeneration as an indicator for forestry restoration in Semideciduous Seasonal Forest in the Southern of Espinha?o, MG.

Louren?o, Alessandra Fonseca 23 August 2016 (has links)
?rea de concentra??o: Recursos florestais. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-06-06T17:23:43Z No. of bitstreams: 2 alessandra_fonseca_louren?o.pdf: 879765 bytes, checksum: 7490aea1a6cc341415b4e1922959eca5 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-06-22T15:31:45Z (GMT) No. of bitstreams: 2 alessandra_fonseca_louren?o.pdf: 879765 bytes, checksum: 7490aea1a6cc341415b4e1922959eca5 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-06-22T15:31:45Z (GMT). No. of bitstreams: 2 alessandra_fonseca_louren?o.pdf: 879765 bytes, checksum: 7490aea1a6cc341415b4e1922959eca5 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Tendo em vista a import?ncia da utiliza??o de indicadores que reflitam o sucesso da restaura??o florestal em um ambiente anteriormente degradado, esse estudo avaliou a regenera??o natural de um ambiente restaurado por plantio direto de mudas com idade de seis anos, em compara??o a um ambiente de refer?ncia (mata conservada), ambos inseridos em Floresta Estacional Semidecidual, no Munic?pio de Dom Joaquim, MG. Os indiv?duos regenerantes com altura ? 0,5 m e di?metro ? altura do peito (DAP) menor ou igual a 5 cm foram amostrados em 38 parcelas de 25 m?, distribu?das em cada ambiente. Os par?metros relacionados ? composi??o de esp?cies (riqueza, diversidade e similaridade), ? estrutura (densidade e ?rea basal) e aos grupos ecol?gicos (s?ndrome de dispers?o e categoria sucessional) foram comparados entre os dois ambientes. O ?ndice de Jaccard mostrou alta similaridade entre os dois ambientes (SJ=54,7%), revelando a forte influ?ncia do ecossistema de refer?ncia como fonte de prop?gulos para o ambiente em restaura??o. N?o houve diferen?a significativa dos par?metros estruturais, do potencial de riqueza de esp?cies e do perfil de diversidade entre os ambientes. Entretanto, houve diferen?a entre os grupos ecol?gicos, nos quais o ambiente em restaura??o apresentou menor propor??o de indiv?duos na guilda n?o-pioneira e na guilda zooc?rica. Com o avan?o da sucess?o no ambiente em restaura??o, espera-se que as guildas se equiparem ?s do ambiente de mata. A inser??o do ambiente em restaura??o em matriz florestal conservada foi determinante para a recomposi??o dos par?metros que obtiveram valores similares aos do ambiente de refer?ncia. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / Due to the importance of using indicators that reflect the success of forest restoration in a previously degraded environment, this study evaluated the natural regeneration of an environment restored till the age of six years, which was previously degraded grasslands, compared to a reference environment (preserved forest), both located in semideciduous forest in Conceicao do Mato, municipality of MG. The regenerating individuals with height ? 0.5 m and diameter at breast height (DBH) less than or equal to 0.05 m were sampled in 38 plots of 25 m?, distributed in each environment. The parameters related to species composition (richness, diversity and similarity), structure (density and basal area) and environmental groups (dispersion syndrome and successional category) were compared between the two environments. The Jaccard index indicated high similarity between the two environments (SJ = 54.7%), showing the strong influence of the forest in environmental floristic composition restoration by the arrival of propagules. No significant differences of structural parameters, the potential of species richness and diversity profile among environments was identified. However, there was a difference between ecological groups, where the environment restoration showed lower proportion of individuals in non-pioneer guild and zoochorous guild. With the advancement of succession environmental restoration, it is expected that the guilds will equip the mata environment. Environmental integration in restoration forest matrix conserved was crucial to the recovery of the parameters obtained similar values to the reference environment.
2

Aplicação da análise dimensional em indicadores ambientais de áreas degradadas pela exploração de cassiterita / Application of the dimensional analysis in environmental indicators of areas degraded by cassiterite exploitation

Fengler, Felipe Hashimoto 05 March 2018 (has links)
Submitted by FELIPE HASHIMOTO FENGLER null (felipe_fengler@hotmail.com) on 2018-03-09T01:06:32Z No. of bitstreams: 1 Tese_felipe_fengler_final.pdf: 3248053 bytes, checksum: b3102f65c7b76975b1871f465ba33210 (MD5) / Approved for entry into archive by Bruna Bacalgini null (bruna@sorocaba.unesp.br) on 2018-03-13T14:29:56Z (GMT) No. of bitstreams: 1 fengler_fh_dr_soro.pdf: 3248053 bytes, checksum: b3102f65c7b76975b1871f465ba33210 (MD5) / Made available in DSpace on 2018-03-13T14:29:56Z (GMT). No. of bitstreams: 1 fengler_fh_dr_soro.pdf: 3248053 bytes, checksum: b3102f65c7b76975b1871f465ba33210 (MD5) Previous issue date: 2018-03-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / No contexto do desenvolvimento sustentável há um paradigma crítico, que retrata a relação entre o capital e a degradação ambiental. Conforme aumenta o cunho socioeconômico de determinada atividade, maior é a permissibilidade da sociedade aos seus efeitos ambientais negativos, sobretudo quando são apenas sentidos em nível local. Porém, após um passado de exemplos adversos, a meta por um estado de equilíbrio tem adquiro notoriedade em busca de uma nova perspectiva de desenvolvimento. Quando atividades de grande relevância, como a mineração, resultam em elevado grau de alteração do meio, há expectativa da sociedade quanto à mitigação ou compensação dos seus efeitos negativos, principalmente quando ecossistemas sensíveis são afetados. Porém, a complexidade ambiental dificulta a mensuração da extensão dos danos ambientais, bem como a efetividade de ações de recuperação. Nesse contexto se insere o presente estudo. Buscaram-se métricas e métodos compreensivos para a avaliação de florestas em recuperação em áreas minerarias na Amazônia brasileira. A técnica de modelagem com Análise Dimensional foi empregada de maneira a estabelecer índices adimensionais voltados à avaliação desses ambientes. Variáveis relacionadas ao desenvolvimento florestal, fauna, além das condições físicas, químicas e bioquímicas do solo foram empregadas, utilizando a priori o processo de conhecimento por descoberta em banco de dados em sua seleção. Dois estudos preliminares a Análise Dimensional foram realizados, fornecendo suporte para escolha das variáveis e entendimento da representatividade dos índices adimensionais obtidos. Como resultado uma proposta metodológica foi apresentada, para avaliação da condição fitossociológica de ambientes em recuperação em comparação ao ecossistema de referência. O grau de alteração do solo se mostrou como um dos fatores condicionantes, destacando a importância das ações iniciais de preparo, preliminarmente ao plantio. A análise dimensional se revelou como uma abordagem promissora, possibilitando sintetizar, representar e comparar as condições ambientais dos locais minerados e do ecossistema de referência. Porém, três índices assumiram um papel protagonista, com representação sistêmica do processo de recuperação ambiental, o primeiro expresso pela relação entre duas variáveis bioquímicas do solo, a respiração basal e atividade celulase (Pi2); o segundo (Pi8) obtido através de variáveis biológicas da fauna e da flora; e o terceiro (Pi10), integrando variáveis do solo, da fauna e da flora. Os resultados obtidos permitiram condensar avanços conceituais e metodológicos nesse documento, estruturando uma base para elaboração de propostas de avaliação de ecossistemas alterados e estabelecimentos de padrões de qualidade com base no ecossistema de referência Amazônico. / There is a critical paradigm that portrays the sustainable development, the relationship between the capital and the environmental degradation. As the socioeconomic importance of a given activity increases, the greater will be the permissibility of society to its negative impacts, especially when they are only sensed at the local level. However, after several adverse examples in history, the aim for a state of equilibrium has acquired notoriety for a new perspective of development. When an activity of great relevance, as mining, results in high environmental alteration, there is an expectation of mitigation, or compensation, on its negative effects, especially when vulnerable ecosystems were affected. However, the environmental complexity not always allows a full comprehension of environmental damage, as well as the effectiveness of recovery actions in their reversal. This study aimed to search for comprehensive metrics and methods to evaluate of mined forests of Brazilian Amazonia. Dimensional Analysis was employed in establishing dimensionless index related to the environmental quality of the mined forests. Variables of forest development, fauna, and physical, chemical and biochemical conditions of the soil were employed, based on knowledge discovery in databases in its selection. Two preliminary studies to Dimensional Analysis were carried out, supporting the choice of variables and the further understanding about obtained dimensionless index. As a result, a methodological proposal was presented to evaluate the phytosociological conditions of recovering environments compared to the reference ecosystem. The degree of soil alteration was shown as a conditioning factor, highlighting the importance of the initial soil preparing actions, preliminary to revegetation. The dimensional analysis proved to be a promising approach, allowing synthesizing, representing and comparing the environmental conditions of the mined sites with the reference ecosystem. However, three indices played a major role, with systemic representation of the environmental recovery process, the first one expressed by the relationship between soil basal respiration and cellulase activity (Pi2), the second (Pi8), obtained through biological variables of fauna and flora; and the third (Pi10), integrating soil, fauna and flora variables. The obtained results allowed to condense conceptual and methodological advances in this document, structuring a basis for elaborating evaluation proposals for altered ecosystems and to establish quality standards, based on the reference ecosystem.
3

Réhabilitation écologique d’écosystèmes dégradés par l’exploitation des carrières : faire avec, refaire ou laisser faire la nature ? / Ecological rehabilitation of degraded ecosystems through quarries exploitation : do with, redo or let nature do?

Chenot, Julie 29 October 2018 (has links)
L’écologie de la restauration est une discipline scientifique qui a vu le jour il y a une quarantaine d’années pour tenter de compenser les impacts négatifs du développement des sociétés sur les écosystèmes. Aujourd’hui, suite à des méta-analyses planétaires révélant le succès relatif des opérations de restauration écologique, une nouvelle question émerge : faut-il restaurer activement ou laisser en libre évolution les écosystèmes dégradés ? C’est dans ce contexte que ce projet de thèse a eu lieu avec une démarche qui s’est voulue pluridisciplinaire et a porté sur l’étude de l’impact de carrières sur la steppe méditerranéenne de Crau (Bouches-du-Rhône, France). Deux cas ont été pris en compte, (i) d’anciennes carrières exploitées dans les années 1970 et abandonnées présentant une diversité de modalités d’exploitation ou de réaménagement et, (ii) une carrière encore en cours d’exploitation dont la législation oblige la remise en état. L’objectif est de mieux identifier les éventuels verrous scientifiques en matière de connaissances pour la restauration et mieux définir les attentes sociétales afin de proposer au final une stratégie générale destinée à servir à la gestion future de ces écosystèmes. Les recherches de cette thèse se sont basées sur deux grandes questions, réflexions : (1) Les opérations de restauration écologique mises en place permettent-elles de restaurer l’écosystème de référence (= ici l’écosystème préexistant) ? En comparant différents traitements de restauration sur le long terme (transfert de sol selon différentes modalités, dépôts de matériaux anthropogéniques, absence de réhabilitation), nous avons pu montrer que le transfert de sol reste une bonne méthode, surtout lorsque les caractéristiques initiales du sol sont respectées. Néanmoins, il ne compense toujours pas à moyen-terme (35 ans) la destruction de l'écosystème préexistant : le sol et la communauté végétale de la steppe de référence ne sont pas encore complètement rétablis. Une deuxième technique de mélange de sol lorsque le sol originel n’est plus disponible a également été testée, mais elle ne présente pas non plus un succès total de restauration à court terme (3 ans). Une deuxième question s’est donc posée en parallèle: (2) Sans restauration active, quelle est la valeur de la biodiversité générée par les activités humaines ? Et plus globalement, quelles natures voulons-nous ? Les carrières ont détruit l’écosystème steppique qui préexistait mais ont créé également de nouvelles conditions (pédologiques, de nouveaux habitats) qui soutiennent le fonctionnement et la connectivité d’espèces pionnières et abritent une importante biodiversité patrimoniale absente de l’écosystème d’origine. De plus, la comparaison entre les paysages de carrières et l’écosystème de référence auprès de différents acteurs territoriaux et du grand public a montré que les anciennes carrières sont perçues comme étant beaucoup plus naturelles que la steppe de référence et qu’elles sont également associées à une importante biodiversité. Ces résultats pourraient donc réorienter les choix de restauration ou de gestion, afin de choisir entre 1) ce qui est actuellement recommandé (une restauration active appliquée en fin d’exploitation avec l’écosystème historique en référence) et 2) une libre expression de la nature férale encore appelée restauration passive (avec ou pas réaffectation initiale ; i.e. où l’écosystème de référence est différent de l’écosystème préexistant). / Restoration ecology is a scientific discipline that has emerged forty years ago to try to compensate the negative impacts of society development on ecosystems. Today, following global meta-analyzes revealing the relative success of ecological restoration, a new question emerges: should we actively or passively restore degraded ecosystems? It is in this context that this thesis project took place with a multidisciplinary approach and focused on the study of quarrying impacts on the Mediterranean steppe of Crau (Bouches-du-Rhône, France). Two cases were taken into account: (i) old quarries operated in the 1970s and abandoned then, presenting a variety of exploitation types or rehabilitation modalities, and (ii) a quarry still in the process of exploitation, the legislation now requiring repairs. The aim is to better identify possible scientific obstacles in the field of knowledge for ecological restoration and better define societal expectations in order to finally propose a general strategy intended to serve the future management of these ecosystems. The research of this thesis was based on two major questions, reflections: (1) Do ecological restoration actions restore the reference ecosystem (= the pre-existing ecosystem)? By comparing different long-term restoration treatments (various types of soil transfers, anthropogenic deposits, lack of rehabilitation), we were able to show that soil transfer is still the best method, especially when the initial characteristics of the soil are respected. However, it still does not compensate in the medium term (35 years) for the destruction of the pre-existing ecosystem: the soil and the plant community of the reference steppe are not completely restored yet. A second soil mixing technique used when the original soil is no longer available has also been tested, but it is not very successful either in the short-term (3 years). A second question arose in parallel: (2) Without active restoration, what is the value of biodiversity generated by human activities? And more generally, what kind of nature do we want? Quarries have destroyed the pre-existing steppe ecosystem but have also created new conditions (soil, new habitats) that support the functioning and connectivity of pioneer species and shelter important heritage biodiversity that is absent from the pre-existing ecosystem. In addition, the comparison between the quarry landscapes and the reference ecosystem landscapes with different stakeholders and the general public has shown that the old quarries are perceived as being much more natural than the reference steppe and that they are also associated to an important biodiversity. These results could therefore reorient the choice of restoration or management, in order to choose between 1) what is currently recommended (active restoration applied after the end of quarry exploitation with the historical ecosystem as a reference) and 2) the free expression of feral nature also called passive restoration (with or without reclamation, i.e. where the reference ecosystem is different from the pre-existing ecosystem).

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