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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.
11

Invasão de nicho acústico e diversidade funcional acústica em ambientes invadidos pela rã-touro Lithobates catesbeianus

Medeiros, Camila Ineu January 2015 (has links)
As invasões biológicas são consideradas a segunda maior causa de perda de biodiversidade, pois podem causar diversos impactos ecológicos. Recentemente foi chamado à atenção um novo mecanismo pelo qual espécies invasoras podem afetar as nativas: através da interferência no nicho acústico. O mascaramento dos sinais a partir de fontes de ruídos pode afetar diretamente a fisiologia reprodutiva ou o consumo de energia. A vocalização está diretamente ligada com a seleção sexual em anfíbios, aves, insetos e muitos mamíferos, de maneira que a presença de novas fontes sonoras no ambiente pode afetar a aptidão das espécies. Uma das piores invasoras do mundo, a rã-touro Lithobates catesbeianus, nativa dos EUA, Canadá e México, está distribuída em mais de 40 países, e em pelo menos 130 municípios brasileiros. A rã-touro possui uma vocalização de amplo espectro de frequências, diferente do que é encontrado nas espécies nativas brasileiras. Seus cantos têm frequência dominante baixa, grande propagação e pouca degradação e atenuação no ambiente. A presença do canto da espécie pode causar alteração nos parâmetros dos cantos de uma espécie nativa da Mata Atlântica brasileira. Entretanto, não é sabido se outras espécies também podem ser afetadas e se a introdução da rã-touro é capaz de afetar o comportamento acústico das comunidades nativas. Neste estudo, nós avaliamos os efeitos da invasão de L. catesbeianus sobre o nicho acústico das espécies nativas, usando duas perspectivas, no nível de indivíduos e de comunidades. No Capítulo I nós avaliamos se o estímulo acústico da rã-touro pode alterar parâmetros temporais e espectrais dos cantos de espécies nativas com e sem sobreposição espectral com a espécie invasora. Nós testamos a hipótese de que espécies com sobreposição de frequências com a invasora apresentam mudanças maiores nos parâmetros de vocalização do que espécies que estejam fora desse espectro. Para isso realizamos um experimento em campo, introduzindo a vocalização da espécie em área onde não existe registro da sua ocorrência. Nós utilizamos mais dois estímulos, um ruído branco e uma vocalização de uma espécie nativa, Rhinella icterica. Todas as espécies testadas foram expostas aos três estímulos, onde comparamos com a sua atividade de vocalização espontânea. Nossos resultados mostram efeito de todos os tipos de ruídos nos cantos, mas todas as espécies responderam com mudanças maiores nos parâmetros para os dois anuros do que para o ruído. É provável que esse resultado esteja relacionado ao fato de que ambas as espécies de anuros utilizados nos experimentos tenham a frequência dominante baixa. Entretanto, os resultados reforçam que a introdução de novos sons no ambiente tem potencial de modificar os cantos. No Capítulo II, nós testamos se existe diferença na diversidade funcional acústica em ambientes com e sem a presença de L. catesbeianus em áreas invadidas da Mata Atlântica no sul do Brasil. Nós testamos a hipótese de que poças com a presença dos machos de rã-touro em atividade de vocalização e poças sem a presença dos mesmos apresentam distintos padrões de diversidade funcional acústica e composição funcional acústica mais homogênea. Para isso, nós utilizamos dados coletados em 15 pares de poças invadidas e não invadidas na Mata Atlântica no sul do Brasil e realizamos análises de diversidade e composição funcional utilizando atributos acústicos. Nossos resultados mostram que a composição funcional foi mais homogênea nas poças invadidas do que nas poças não invadidas. Nessas poças, há uma seleção de frequências, onde predominantemente as espécies com frequências dominantes mais altas vocalizam. Ou seja, as espécies que não possuem sobreposição de frequência dominante com a rã-touro. Este estudo é um dos primeiros a testar efeitos da invasão do nicho acústico sobre as comunidades nativas. Ambientes nativos podem ser vulneráveis à introdução de espécies generalistas que produzem sinais de baixa frequência e grande amplitude. Assim, a eficiência de propagação dos sinais confere à rã-touro vantagem adaptativa na comunicação e reprodução, favorecendo o processo de estabelecimento e dispersão em detrimento das espécies nativas. / Biological Invasions are considered the second leading cause of biodiversity loss, because they may cause many ecological impacts. Recently, was called attention to a new mechanism by which invasive species can affect native species: through interference in the acoustic niche. The masking of signals from noise sources can directly affect reproductive physiology or energy consumption. Vocalization is directly connected with the sexual selection in amphibians, birds, insects, and many mammals, so that the presence of new sound sources in the environment can affect the fitness of the species. One of the worst invasive species of the world, the bullfrog Lithobates catesbeianus, native from USA, Canada and Mexico, is distributed in over 40 countries around the world and, at least, 130 Brazilian municipalities. The bullfrog has a wide spectrum of frequencies vocalization, different from what is founded in Brazilian native species. Their calls have low dominant frequency, large propagation and little degradation and attenuation in the environment. The presence of the species’ call can cause changes in the parameters of the native species’ calls from Brazilian Atlantic Forest. However, it is not known if other species may also be affected and the introduction of bullfrogs can affect the acoustic behavior of the native communities. In this study, we evaluated the effects of L. catesbeianus invasion on the acoustic niche of native species, using two perspectives at the level of individuals and communities. In Chapter I we evaluate how the acoustic stimulus of bullfrogs can change temporal and spectral parameters of the native species’ calls with and without spectral overlap with invasive species. We tested the hypothesis that species with overlapping frequencies with the invading show greater change in vocalization parameters than species outside this spectrum. To make this we conducted a field experiment, introducing the vocalization of the invasion species in an area where there is no record of their occurrence. We used two stimuli, a white noise and calling of a native species, Rhinella icterica. All species tested were exposed to the three stimuli, which compared with its spontaneous vocalization activity. Our results show the effect of all kinds of noise at the calls, but all the species responded with large changes in the parameters for the two frogs than for noise. It is probable that this result is related to the fact that both species of frogs used in the experiments have low dominant frequency. However, the results reinforce the introduction of new sounds in the environment has the potential to modify the native calls. In Chapter II, we tested if exist differences in the acoustic functional diversity in environment with and without the presence of L. catesbeianus in invaded areas of the Atlantic Forest in southern Brazil. We tested the hypothesis that the ponds with presence of bullfrog males in vocalization activity and ponds without their presence have distinct patterns of acoustic functional diversity and acoustic functional composition more homogeneous. For this, we used data collected from 15 pairs of ponds invaded and not invaded by bullfrog in the Atlantic Forest in southern Brazil and realized analysis of diversity and functional composition using acoustic traits. Our results show that the functional composition was more homogeneous in ponds invaded than in ponds not invaded. In these ponds, there is a selection of frequencies, where predominantly the species that vocalize at highest frequencies are calling, that don´t have dominant frequency overlap with the bullfrog. This study is one of the first to test effects of acoustic niche invasion on native communities. Native environments may be vulnerable to the introduction of generalist species that produces low frequency and large amplitude signals. Therefore, signal propagation efficiency gives the bullfrog adaptive advantage in communication and reproduction, favoring the process of establishment and dispersion at the expense of native species.
12

Invasão de nicho acústico e diversidade funcional acústica em ambientes invadidos pela rã-touro Lithobates catesbeianus

Medeiros, Camila Ineu January 2015 (has links)
As invasões biológicas são consideradas a segunda maior causa de perda de biodiversidade, pois podem causar diversos impactos ecológicos. Recentemente foi chamado à atenção um novo mecanismo pelo qual espécies invasoras podem afetar as nativas: através da interferência no nicho acústico. O mascaramento dos sinais a partir de fontes de ruídos pode afetar diretamente a fisiologia reprodutiva ou o consumo de energia. A vocalização está diretamente ligada com a seleção sexual em anfíbios, aves, insetos e muitos mamíferos, de maneira que a presença de novas fontes sonoras no ambiente pode afetar a aptidão das espécies. Uma das piores invasoras do mundo, a rã-touro Lithobates catesbeianus, nativa dos EUA, Canadá e México, está distribuída em mais de 40 países, e em pelo menos 130 municípios brasileiros. A rã-touro possui uma vocalização de amplo espectro de frequências, diferente do que é encontrado nas espécies nativas brasileiras. Seus cantos têm frequência dominante baixa, grande propagação e pouca degradação e atenuação no ambiente. A presença do canto da espécie pode causar alteração nos parâmetros dos cantos de uma espécie nativa da Mata Atlântica brasileira. Entretanto, não é sabido se outras espécies também podem ser afetadas e se a introdução da rã-touro é capaz de afetar o comportamento acústico das comunidades nativas. Neste estudo, nós avaliamos os efeitos da invasão de L. catesbeianus sobre o nicho acústico das espécies nativas, usando duas perspectivas, no nível de indivíduos e de comunidades. No Capítulo I nós avaliamos se o estímulo acústico da rã-touro pode alterar parâmetros temporais e espectrais dos cantos de espécies nativas com e sem sobreposição espectral com a espécie invasora. Nós testamos a hipótese de que espécies com sobreposição de frequências com a invasora apresentam mudanças maiores nos parâmetros de vocalização do que espécies que estejam fora desse espectro. Para isso realizamos um experimento em campo, introduzindo a vocalização da espécie em área onde não existe registro da sua ocorrência. Nós utilizamos mais dois estímulos, um ruído branco e uma vocalização de uma espécie nativa, Rhinella icterica. Todas as espécies testadas foram expostas aos três estímulos, onde comparamos com a sua atividade de vocalização espontânea. Nossos resultados mostram efeito de todos os tipos de ruídos nos cantos, mas todas as espécies responderam com mudanças maiores nos parâmetros para os dois anuros do que para o ruído. É provável que esse resultado esteja relacionado ao fato de que ambas as espécies de anuros utilizados nos experimentos tenham a frequência dominante baixa. Entretanto, os resultados reforçam que a introdução de novos sons no ambiente tem potencial de modificar os cantos. No Capítulo II, nós testamos se existe diferença na diversidade funcional acústica em ambientes com e sem a presença de L. catesbeianus em áreas invadidas da Mata Atlântica no sul do Brasil. Nós testamos a hipótese de que poças com a presença dos machos de rã-touro em atividade de vocalização e poças sem a presença dos mesmos apresentam distintos padrões de diversidade funcional acústica e composição funcional acústica mais homogênea. Para isso, nós utilizamos dados coletados em 15 pares de poças invadidas e não invadidas na Mata Atlântica no sul do Brasil e realizamos análises de diversidade e composição funcional utilizando atributos acústicos. Nossos resultados mostram que a composição funcional foi mais homogênea nas poças invadidas do que nas poças não invadidas. Nessas poças, há uma seleção de frequências, onde predominantemente as espécies com frequências dominantes mais altas vocalizam. Ou seja, as espécies que não possuem sobreposição de frequência dominante com a rã-touro. Este estudo é um dos primeiros a testar efeitos da invasão do nicho acústico sobre as comunidades nativas. Ambientes nativos podem ser vulneráveis à introdução de espécies generalistas que produzem sinais de baixa frequência e grande amplitude. Assim, a eficiência de propagação dos sinais confere à rã-touro vantagem adaptativa na comunicação e reprodução, favorecendo o processo de estabelecimento e dispersão em detrimento das espécies nativas. / Biological Invasions are considered the second leading cause of biodiversity loss, because they may cause many ecological impacts. Recently, was called attention to a new mechanism by which invasive species can affect native species: through interference in the acoustic niche. The masking of signals from noise sources can directly affect reproductive physiology or energy consumption. Vocalization is directly connected with the sexual selection in amphibians, birds, insects, and many mammals, so that the presence of new sound sources in the environment can affect the fitness of the species. One of the worst invasive species of the world, the bullfrog Lithobates catesbeianus, native from USA, Canada and Mexico, is distributed in over 40 countries around the world and, at least, 130 Brazilian municipalities. The bullfrog has a wide spectrum of frequencies vocalization, different from what is founded in Brazilian native species. Their calls have low dominant frequency, large propagation and little degradation and attenuation in the environment. The presence of the species’ call can cause changes in the parameters of the native species’ calls from Brazilian Atlantic Forest. However, it is not known if other species may also be affected and the introduction of bullfrogs can affect the acoustic behavior of the native communities. In this study, we evaluated the effects of L. catesbeianus invasion on the acoustic niche of native species, using two perspectives at the level of individuals and communities. In Chapter I we evaluate how the acoustic stimulus of bullfrogs can change temporal and spectral parameters of the native species’ calls with and without spectral overlap with invasive species. We tested the hypothesis that species with overlapping frequencies with the invading show greater change in vocalization parameters than species outside this spectrum. To make this we conducted a field experiment, introducing the vocalization of the invasion species in an area where there is no record of their occurrence. We used two stimuli, a white noise and calling of a native species, Rhinella icterica. All species tested were exposed to the three stimuli, which compared with its spontaneous vocalization activity. Our results show the effect of all kinds of noise at the calls, but all the species responded with large changes in the parameters for the two frogs than for noise. It is probable that this result is related to the fact that both species of frogs used in the experiments have low dominant frequency. However, the results reinforce the introduction of new sounds in the environment has the potential to modify the native calls. In Chapter II, we tested if exist differences in the acoustic functional diversity in environment with and without the presence of L. catesbeianus in invaded areas of the Atlantic Forest in southern Brazil. We tested the hypothesis that the ponds with presence of bullfrog males in vocalization activity and ponds without their presence have distinct patterns of acoustic functional diversity and acoustic functional composition more homogeneous. For this, we used data collected from 15 pairs of ponds invaded and not invaded by bullfrog in the Atlantic Forest in southern Brazil and realized analysis of diversity and functional composition using acoustic traits. Our results show that the functional composition was more homogeneous in ponds invaded than in ponds not invaded. In these ponds, there is a selection of frequencies, where predominantly the species that vocalize at highest frequencies are calling, that don´t have dominant frequency overlap with the bullfrog. This study is one of the first to test effects of acoustic niche invasion on native communities. Native environments may be vulnerable to the introduction of generalist species that produces low frequency and large amplitude signals. Therefore, signal propagation efficiency gives the bullfrog adaptive advantage in communication and reproduction, favoring the process of establishment and dispersion at the expense of native species.
13

Evaluation des services fourragers et environnementaux des prairies permanentes à partir de la végétation, du milieu et des pratiques de gestion / Evaluation of agronomic and environmental services of permanent grasslands from vegetation, environment and management

Michaud, Audrey 27 June 2011 (has links)
Les prairies permanentes (PP) jouent un rôle agronomique et environnemental important. Cependant, leur faible niveau de subventions, une méconnaissance de leur fonctionnement et un désintérêt de ces surfaces au profit de productions fourragères plus productives ont accéléré leur retournement. Revaloriser ces surfaces dans les systèmes fourragers en mettant notamment en avant les services rendus par les PP est donc un enjeu important. Dans ce cadre, l’objectif de notre étude était d’identifier des descripteurs pédoclimatiques et des pratiques de gestion ainsi que les états de la végétation pertinents pour prédire ces services. Notre approche s’est appuyée sur une démarche en plusieurs étapes : i) identification et caractérisation des services fourragers et environnementaux pertinents pour les PP, ii) identification des critères d’aptitude (valeur nutritive, quantité de nectar disponible…), qui permettent d’évaluer le degré d’atteinte du service, iii) prévision des valeurs de chaque critère d’aptitude à partir des états de la végétation (composition botanique et fonctionnelle) et iv) construction des liens entre les états de la végétation et des descripteurs pédoclimatiques (température, régime hydrique…) et de pratiques de gestion (fertilisation, date de première fauche…). Un travail de bibliographie, d’expertise et d’enquêtes en ferme a permis de sélectionner les services fourragers et environnementaux, les critères d’aptitude, les états de la végétation et les descripteurs pédoclimatiques et des pratiques de gestion. Au total, quatre services environnementaux et 10 services fourragers ont été étudiés, en tenant compte de 12 états de la végétation (composition botanique (présence et dominances en espèces) et fonctionnelle (traits de vie et propriétés des espèces)), de 15 descripteurs pédoclimatiques (température, humidité du sol, …) et 19 descripteurs des pratiques de gestion (fertilisation, intensité d’utilisations de la prairie,...). L’étude d’un réseau national de 190 parcelles nous a permis de montrer que les compositions fonctionnelle et botanique sont non redondantes et influencées par des descripteurs pédoclimatiques et des pratiques de gestion différentes. La composition fonctionnelle est influencée par des descripteurs pédoclimatiques et des pratiques de gestion alors que la composition botanique, qui fait appel à un plus grand nombre de descripteurs, est majoritairement prédite par des descripteurs pédoclimatiques. Les modèles de prévisions sont meilleurs pour la composition botanique que pour la composition fonctionnelle. L’étude de ce réseau ainsi que d’un dispositif en station expérimentale nous ont permis d’évaluer la qualité de prédiction des critères d’aptitude fourragers (production et valeur nutritive) à partir de la composition fonctionnelle (types fonctionnels (TF) de graminées, proportion de graminées, légumineuses et diverses) de la végétation. L’étude, dans un même milieu de trois prairies de composition en TF contrastée confirme sur l’ensemble de la saison de végétation les différences de qualité et de production de la prairie induites par la composition en TF. En revanche, à l’échelle du réseau national de prairies, la composition en TF n’explique qu’une part limitée des variations de qualité et de production observées. D’autres états de la végétation comme les proportions de légumineuses et de plantes diverses, ainsi que le stade moyen de la végétation et la teneur en matière sèche de la prairie contribuent également à expliquer les différences de production et de qualité entre prairies. Enfin une démarche multicritères nous a permis de construire une méthode d’évaluation des services fourragers et environnementaux à partir des critères d’aptitude. / The contribution of permanent grasslands (PG) to agronomic and environmental services is important. However, their low level of subsidies, a lack of knowledge about their management and a disinterest of these surfaces in favour of more productive forage production have accelerated their downturn. The upgrade of these surfaces in forage systems in particular by studying services of PG is an important issue. In this context, the objective of our study was to identify pedoclimatic and management practices descriptors and characteristics of the vegetation relevant to predict these services. Our approach was based on different steps: i) identification and characterization of forage and environmental services relevant to the PG, ii) identification of aptitude criteria (herbage quality, amount of nectar available ...) which allow to assess the degree of achievement of the services, iii) prediction of values for each criterion of aptitude from characteristics of vegetation (botanical and functional composition) and iv) building links between characteristics of vegetation and pedoclimatic (temperature, soil moisture) and management practices (fertilization, date of first cut) descriptors. From the literature survey, expertise and farm surveys we selected the forage and environmental services, the criteria of aptitude, the characteristics of vegetation and pedoclimatic and management practices descriptors. In total, four environmental services and 11 feed services were studied, taking into account the 12 characteristics of the vegetation (botanical composition (presence and dominance of species) and functional composition (life traits and properties of species)), 15 pedoclimatic descriptors (temperature, soil moisture ...) and 19 management practices descriptors (fertilization, intensity of use of grassland...). The study of a national network of 190 grasslands allowed us to show that botanical and functional composition are non-redundant and influenced by different pedoclimatic and management practices descriptors. The functional composition is influenced by pedoclimatic and management practices descriptors while the botanical composition, which uses a larger number of descriptors, is mainly predicted by pedoclimatic descriptors. The model predictions are better for the botanical composition than for the functional composition. The study of this network and of an experiment in control conditions allowed us to evaluate the quality of prediction of criteria of aptitude for forage services from the functional composition (functional types (FT), proportion of grasses, legumes and forbs, middle stage and dry matter content) of the vegetation. The study in a common environment of three grasslands contrasted on FT composition confirms on the whole growth season the differences in quality and production of grassland that are linked to the FT composition. In contrast, at the scale of the national grassland network, FT composition alone is not sufficient to predict the observed differences in production and quality. Other characteristics of vegetation such as the proportion of legumes and forbs, as well as the mean stage of vegetation or the dry matter content also contribute to explain the differences in production and quality between grasslands. Finally, a multicriteria approach allowed us to build an evaluation method of forage and environmental services from the criteria of aptitude.Thus, this thesis work allowed the development of a method to predict the forage and environmental services provided by permanent grasslands from the knowledge of pedoclimatic characteristics, management practices and of simple vegetation criteria
14

Land use history promotes shifts in composition and increases the functional vulnerability of urban forests

Pyles, Marcela Venelli 21 February 2018 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2018-05-18T11:35:54Z No. of bitstreams: 1 marcelavenellipyles.pdf: 949685 bytes, checksum: 7bf12c1e314a606c615e187c4d2bb940 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-09-03T16:03:30Z (GMT) No. of bitstreams: 1 marcelavenellipyles.pdf: 949685 bytes, checksum: 7bf12c1e314a606c615e187c4d2bb940 (MD5) / Made available in DSpace on 2018-09-03T16:03:30Z (GMT). No. of bitstreams: 1 marcelavenellipyles.pdf: 949685 bytes, checksum: 7bf12c1e314a606c615e187c4d2bb940 (MD5) Previous issue date: 2018-02-21 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A urbanização está transformando rapidamente nosso mundo e ameaçando a manutenção das funções do ecossistema, como biodiversidade e produção primária. Este estudo teve como objetivo compreender como diferentes histórias de uso da terra afetam a composição funcional e a diversidade das florestas urbanas e quão funcionalmente vulneráveis são essas florestas a futuros distúrbios. Utilizamos dados de nove florestas urbanas com diferentes históricos de uso da terra (HUT), agrupadas em três categorias de intensidade com três florestas em cada: desnudamento do solo (alta intensidade de HUT), cultivo (intensidade média de HUT) e sem histórico de uso da terra (baixa intensidade de HUT) e de três florestas maduras não urbanas (controle), para fins de comparação, todas situadas na Floresta Atlântica Brasileira. Abordamos duas questões: (i) em que medida as florestas urbanas com diferentes históricos de uso da terra diferem na composição e diversidade funcional e (ii) qual é a consequência do histórico de uso da terra na resistência e resiliência funcional das florestas urbanas? A primeira pergunta foi respondida através da categorização de espécies em grupos funcionais e pelos índices de riqueza funcional e dispersão; e a segunda através de uma análise de resistência, baseada em redundância funcional, e uma análise de resiliência, baseada na diversidade de resposta de espécies. Como prevemos, as florestas urbanas mostraram alterações na composição funcional, independente do histórico de uso. No entanto, efeitos negativos sobre a quantidade e diversidade funcional foram apenas encontrados em florestas com uso prévio da terra mais intenso (desnudamento do solo e cultivo). Apenas as florestas urbanas com histórico de uso da terra tiveram reduções significativas na redundância funcional e na diversidade de respostas das espécies. Surpreendentemente, as florestas urbanas sem histórico de uso da terra são capazes de manter altos níveis de diversidade e segurança funcional, semelhantes aos encontrados nas florestas não urbanas. Concluímos que, embora as florestas urbanas ainda possam servir como reservatórios de diversidade funcional e apresentar alguma segurança no fornecimento de suas funções diante de futuros distúrbios, a intensidade o uso prévio da terra é determinante para a redução, homogeneização e vulnerabilidade funcional dessas florestas. / Urbanisation is rapidly transforming our world and threatening the maintenance of ecosystem functions as biodiversity and primary production. This study aimed to understand how different land-use histories affect functional composition and diversity of urban forests and how functionally vulnerable are these forests to future disturbances. We used data from nine urban forests with different land-use histories (LUH) grouped in three intensity categories with three forests in each: soil denudation (high intensity LUH), cropland (medium intensity LUH) and without land use history (low intensity LUH) and from three non-urban mature forests (control), for comparison purposes, all situated in the Brazilian Atlantic forest. We addressed two questions: (i) to what extent do urban forests with different land-use histories differ in functional composition and diversity metrics?; and (ii) how functionally vulnerable are these forests to future disturbances? The first was answered from the species categorization into functional groups and by the functional richness and dispersion indices; and the second through a resistance analysis based on functional redundancy and a resilience analysis based on species response diversity. As we predict, urban forests showed differences in functional composition, regardless of the land use history. However, negative effects on the amount and diversity of functions were only related to the more intense previous land use (cropland and denudation LUH). Only urban forests with some land use history had significant reductions in functional redundancy and species response diversity. Surprisingly, urban forests without land use history are able to maintain high levels of functional diversity and safety, similar to those found in nonurban forests. We conclude that, although urban forests can still serve as reservoirs of functional diversity and may present some safety in the provision of their functions in the face of future disturbances, the intensity of land use history is determinant for the functional reduction, homogenization and vulnerability of these urban forests.
15

XML manipulation by non-expert users / Manipulation des données XML par des utilisateurs non-experts

Tekli, Gilbert 04 October 2011 (has links)
Aujourd’hui, les ordinateurs et l’Internet sont partout dans le monde : dans chaque maison, domaine et plateforme. Dans ce contexte, le standard XML s’est établi comme un moyen insigne pour la représentation et l’échange efficaces des données. Les communications et les échanges d’informations entre utilisateurs, applications et systèmes d’information hétérogènes sont désormais réalisés moyennant XML afin de garantir l’interopérabilité des données. Le codage simple et robuste de XML, à base de données textuelles semi-structurées, a fait que ce standard a rapidement envahi les communications medias. Ces communications sont devenues inter-domaines, partant de l’informatique et s’intégrant dans les domaines médical, commercial, et social, etc. Par conséquent, et au vu du niveau croissant des données XML flottantes entre des utilisateurs non-experts (employés, scientifiques, etc.), que ce soit sur les messageries instantanées, réseaux sociaux, stockage de données ou autres, il devient incontournable de permettre aux utilisateurs non-experts de manipuler et contrôler leurs données (e.g., des parents qui souhaitent appliquer du contrôle parental sur les messageries instantanées de leur maison, un journaliste qui désire regrouper et filtrer des informations provenant de différents flux RSS, etc.). L'objectif principal de cette thèse est l'étude des manipulations des données XML par des utilisateurs non-experts. Quatre principales catégories ont été identifiées dans la littérature : i) les langages visuels orientés XML, ii) les Mashups, iii) les techniques de manipulation des données XML, et iv) les DFVPL (langages de programmation visuel à base de Dataflow), couvrant différentes pistes. Cependant, aucune d’entre elles ne fournit une solution complète. Dans ce travail de recherche, nous avons formellement défini un Framework de manipulation XML, intitulé XA2C (XML-oriented mAnipulAtion Compositions). XA2C représente un environnement de programmation visuel (e.g., Visual-Studio) pour un DFVPL orienté XML, intitulé XCDL (XML-oriented Composition Definition Language) qui constitue la contribution majeure de cette thèse. XCDL, basé sur les réseaux de Pétri colorés, permet aux non-experts de définir, d’arranger et de composer des opérations de manipulation orientées XML. Ces opérations peuvent être des simples sélections/projections de données, ainsi que des opérations plus complexes de modifications de données (insertion, suppression, tatouage, etc.). Le langage proposé traite les données XML à base de documents ou de fragments. En plus de la définition formelle (syntaxique et sémantique) du langage XCDL, XA2C introduit une architecture complète à base d’un compilateur et un environnement d'exécution dédiés. Afin de tester et d’évaluer notre approche théorique, nous avons développé un prototype, intitulé X-Man, avec un Framework d’évaluation pour les langages et outils visuels de programmation orientés XML. Une série d'études de cas et d’expérimentations a été réalisée afin d'évaluer la qualité d'usage de notre langage, et de le comparer aux solutions existantes. Les résultats obtenus soulignent la supériorité de note approche, notamment en termes de qualité d’interaction, de visualisation, et d’utilisation. Plusieurs pistes sont en cours d’exploration, telles que l'intégration des opérations plus complexes (opérateurs de contrôle, boucles, etc.), les compositions automatiques, et l’extension du langage pour gérer la spécificité des formats dérivés du standard XML (flux RSS, RDF, SMIL, etc.) / Computers and the Internet are everywhere nowadays, in every home, domain and field. Communications between users, applications and heterogeneous information systems are mainly done via XML structured data. XML, based on simple textual data and not requiring any specific platform or environment, has invaded and governed the communication Medias. In the 21stcentury, these communications are now inter-domain and have stepped outside the scope of computer science into other areas (i.e., medical, commerce, social, etc.). As a consequence, and due to the increasing amount of XML data floating between non-expert users (programmers, scientists, etc.), whether on instant messaging, social networks, data storage and others, it is becoming crucial and imperative to allow non-experts to be able to manipulate and control their data (e.g.,parents who want to apply parental control over instant messaging tools in their house, a journalist who wants to gather information from different RSS feeds and filter them out, etc.). The main objective of this work is the study of XML manipulations by non-expert users. Four main related categories have been identified in the literature: XML-oriented visual languages, Mashups, XML manipulation by security and adaptation techniques, and Dataflow visual programming languages. However, none of them provides a full-fledged solution for appropriate XML data manipulation. In our research, we formally defined an XML manipulation framework, entitled XA2C (XML Alteration/Adaptation Composition Framework). XA2C represents a visual studio for an XML-oriented DFVPL (Dataflow Visual Programming Language), called XCDL (XML-oriented Composition Definition Language) which constitutes the major contribution of this study. XCDL is based on Colored Petri Nets allowing non-expert users to compose manipulation operations. The XML manipulations range from simple data selection/projection to data modification (insertion, removal, obfuscation, etc.). The language is oriented to deal with XML data (XML documents and fragments), providing users with means to compose XML oriented operations. Complementary to the language syntax and semantics, XA2C formally defines also the compiler and runtime environment of XCDL. In addition to the theoretical contribution, we developed a prototype, called X-Man, and formally defined an evaluation framework for XML-oriented visual languages and tools that was used in a set of case studies and experiments to evaluate the quality of use of our language and compare it to existing approaches. The obtained assessments and results were positive and show that our approach outperforms existing ones. Several future tracks are being studied such as integration of more complex operations (control operators, loops, etc.), automated compositions, and language derivation to define specific languages oriented towards different XML-based standards (e.g., RSS, RDF, SMIL, etc.)

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