Invasive species are considered an agent of ecological change with more significant effects than global warming. Exotic plant invasions threaten biodiversity and ecosystem viability worldwide. Their effects in the Sonoran Desert ecosystems are a growing concern among ecologists and land managers. We hypothesized that highly dynamic desert environments are unstable, therefore more vulnerable to invasion by exotic plant species. To test this hypothesis we used a multidimensional approach to assess the spatial distribution of two exotic species: Brassica tournefortii (Saharan mustard) and Schismus arabicus (Arabian grass), in a portion of 'El Pinacate y Gran Desierto de Altar' Biosphere Reserve (PBR) in northwestern Sonora, Mexico. This approach combined genetic algorithms, geographic information systems, field methods, statistical analysis, and remote sensing modeling at multiple spatial and temporal scales to predict and test the current and potential distribution of the invasives over dynamic landscapes.Predicted probability of invasion was influenced strongly by human factors: Road networks were the strongest predictors of presence, revealing the potential importance of humans as vectors of invasiveness. Dynamic landscapes, associated mostly with vegetation losses, were detected spectrally in the eastern portion of the study area, very likely associated with past agricultural and current grazing activity. Combined models of high probability for invasion by B. tournefortii and S. arabicus over dynamic landscapes were tested against confirmed locations of the invasives and land cover types associated with invasion. Results confirmed the hypothesis of the study and suggest that more dynamic landscapes are more prone to invasion by these two exotic plants in the PBR. B. tournefortii was found associated mostly with landscapes occupied by microphyllous desert scrub and grassland, as well as sarcocaulescent desert scrub. S. arabicus was found more abundantly in the flat low lands occupied by microphyllous and crassicaulescent desert scrub. These relationships cannot, however, be conclusive and require further investigation due to the complex ecology of these invasives.

Apesar da vasta literatura sobre os efeitos da perda e fragmentação florestal sobre a biodiversidade, poucos estudos incorporaram o aspecto temporal, ou seja, a história da paisagem, em suas análises. No entanto, o histórico de alterações da paisagem é um dos fatores que, ao ser ignorado, pode levar a interpretação errada dos reais efeitos da perda e fragmentação florestal sobre a diversidade de espécies. Assim, o objetivo desta tese foi avaliar os efeitos do histórico de mudança da paisagem sobre aves e pequenos mamíferos na Mata Atlântica. Para atingir este objetivo eu investiguei (1) a dinâmica de três paisagens fragmentadas de Mata Atlântica entre 1960-1980 e 1980-2000, (2) os efeitos da cobertura florestal passada e atual sobre a riqueza de espécies de espécies e, (3) a plausibilidade de modelos de cobertura vegetal nativa na riqueza de espécies e abundância, considerando ou não a heterogeneidade da vegetação nativa. Para investigar essas questões, foram usados dados de aves e pequenos mamíferos em 53 fragmentos florestais localizados em três paisagens com diferentes proporções de cobertura florestal (10, 30 e 50%) na Mata Atlântica do Planalto Atlântico de São Paulo. Os resultados mostraram que (1) a trajetória da cobertura florestal entre os anos 1960 e 2000 nas três paisagens estudadas foi não-linear e, atualmente, fragmentos florestais consistem de um mosaico de florestas com diferentes idades de regeneração, (2) a existência do débito de extinção e do crédito de espécies, assim como o potencial para o seu pagamento futuro, depende não só da trajetória de cobertura florestal, mas também da cobertura florestal remanescente na escala da paisagem, e (3) a heterogeneidade da vegetação nativa desempenha um papel importante na definição da riqueza de espécies e abundância e que as respostas a essa heterogeneidade são definidas pelos requerimentos de habitat e dependem de cobertura florestal da paisagem. / Despite the extended literature on the effects of forest loss and fragmentation on biodiversity, few studies incorporated the temporal aspect, i.e. the history of change of habitat amount and configuration over time at a given landscape, in the analysis. However, ignoring landscape change history might lead to inaccurate interpretation of the impact of forest loss and fragmentation on species diversity. Thus, the aim of this thesis was to evaluate the effects of landscape change history on birds and small mammals in the Atlantic Forest. To achieve this aim I investigated (1) the land-use and land-cover change dynamics in Atlantic Forest fragmented landscapes between 1960s-1980s and 1980s-2000s, (2) the effects of historical and present-day forest cover on species richness and, (3) the potential of explaining species richness and abundance patterns by inclusion or exclusion of present native vegetation heterogeneity in model frameworks. To address these objectives I used data on birds and small mammals in 53 forest fragments from three landscapes with different proportions of forest cover (10, 30 and 50%) in the Atlantic Forest of Brazil. The results showed that (1) forest cover trajectory between the 1960s and 2000s at the three study landscapes was non-linear and that individual forest patches currently consist of a mosaic of different forest age classes, (2) the existence of extinction debt and species credit as well as the potential for their future payment depends not only on forest cover trajectory but also on the present amount of remaining forest cover at the landscape scale, and (3) the heterogeneity within native vegetation plays an important role in defining species richness and abundance in fragmented landscapes and responses to this heterogeneity are defined by habitat requirements and depend on forest cover at landscape scale.

A indicação do consumo de itens alimentares provenientes de plantas de ciclo fotossintético C3 e C4 pela comunidade de aves pode contribuir na determinação do potencial de resiliência de remanescentes florestais em paisagens agrícolas. O presente estudo buscou avaliar a composição da dieta da comunidade de aves situadas em fragmentos florestais inseridos em paisagem agrícola da bacia do rio Corumbataí, SP, através do uso da ferramenta de isótopos estáveis. Oito remanescentes florestais foram selecionados a partir da análise da idade dos remanescentes, sendo quatro antigos (33 e 49 anos) e quatro recentes (3 e 11 anos), dispostos em igual proporção em unidades amostrais (16 km²), com pelo menos 70% de ocupação pela matriz (pasto ou cana-de-açúcar) e 10% de mata. Foram realizadas 12 repetições em cada remanescente, totalizando 96 coletas. Uma sequência de cinco redes de neblina ornitológicas (malha 32 mm, 12 m x 2,8 m), foi alocada na área nuclear de cada remanescente, permanecendo abertas por um período contínuo de quatro horas, a partir das primeiras horas da manhã, vistoriadas a cada 30 minutos. Amostras de penas foram coletadas para análise isotópica. 33 espécies foram analisadas isotopicamente. A porcentagem de C3 encontrada nos indivíduos de 11 espécies foi relacionada às métricas da paisagem (porcentagem de cana e pasto e porcentagem de mata ou área nuclear, taxa anual de mudança, perfil da curva de mudança florestal e idade média). 81 espécies pertencentes a 27 famílias foram identificadas em 979 capturas. As mais frequentemente capturadas no período foram B. hypoleucus (84,38%), A. galeata (83,33%) e P. mystaceus (71,88%). Não houve diferença estatística entre riqueza em comunidades situadas em pasto e cana ou entre remanescentes antigos e recentes. A similaridade entre as comunidades presentes em matrizes de pasto e cana foi de 50,62%, sendo de 48,15% comparando-se remanescentes florestais antigos e recentes. As análises isotópicas das 33 espécies evidenciaram diferenças no uso de recursos provenientes de plantas de ciclo fotossintético C3 e C4. 78,79% das espécies possuíam uma dieta média com mais de 70% de sua alimentação baseada exclusivamente no consumo de itens C3, 21,21% consumidoras de C3 e C4 e nenhuma espécie com média predominantemente de itens C4. A análise individual, porém, mostrou indivíduos de T. fuliginosus e B. flaveolus com predomínio de C4 em sua dieta. Dentre as 11 espécies, seis (A. galeata, A. flavirostris, B. flaveolus, L. euleri, T. coronatus e T. leucomelas) mostraram relação com as variáveis da paisagem testadas. A composição da dieta das espécies foi afetada principalmente pela idade média do remanescente, havendo divergência quanto ao padrão de resposta em relação ao tipo e a proporção da matriz na paisagem. Embora os fragmentos amostrados estejam em avançado grau de degradação, os resultados corroboram para a necessidade de manutenção destes remanescentes como forma de manter a biodiversidade de aves. / Information on the consumption of food items from plants of C3 and C4 photosynthetic cycle by a bird community can help determine the potential resilience of forest remnants in agricultural landscapes. This study assessed the diet composition of bird communities in forest fragments embedded in the agricultural landscape of the Corumbataí River basin, São Paulo State, Brazil, using stable isotopes. Eight forest fragments were selected based on their ages, being four classified as \"old\" (33 and 49 years of age) and four \"young\" (3 to 11 years of age), arranged in equal proportion in sample units (16 km²), with at least 70% of occupation by the matrix (pasture or sugarcane) and 10% of forest. We performed 12 repetitions in each remnant, totaling 96 sampling. A sequence of five ornithological mist nets (32 mm mesh, 12 m x 2.8 m) was allocated in the nuclear area of each remnant, remaining open for a continuous period of four hours, in the early morning hours. The nets were inspected every 30 minutes. Feather samples were collected for isotopic analysis. We analyzed isotopically 33 species. The percentage of C3 found in individuals of 11 species was related to landscape metrics (percentage of sugarcane and pasture and percentage of forest or nuclear area, mean annual forest change rate, forest change curvature profile and average age). We identified 81 species belonging to 27 families in 979 catches. The most frequently captured species were B. hypoleucus (84.38%), A. galeata (83.33%) and P. mystaceus (71.88%). There was no statistical difference for predominance between the communities in pasture and sugarcane or between old and young remnants. The similarity between the communities in pasture and sugarcane matrices was 50.62%, and 48.15% comparing old and young forest remnants. The isotope analysis of 33 species showed differences in the use of plant resources of C3 and C4 photosynthetic cycle. A total of 78.79% of species had a diet average over 70% of its food consumption solely based on C3 plants, 21.21% consumed C3 and C4 and no species showed predominant consumption of C4 plants. Individual analysis, however, showed that T. fuliginosus and B. flaveolus predominantly consumed C4 plants. Among the 11 species studied, six (A. galeata, A. flavirostris, B. flaveolus, L. euleri, T. coronatus and T. leucomelas) showed a relationship with the landscape variables tested. Diet composition of species was mainly affected by the remnant average age, and results were different regarding the type and ratio of the landscape matrix. Although the fragments sampled are in advanced stage of degradation, the results corroborate the need to preserve these remnants to maintain biodiversity of birds.

In recent years, human decision-making has led to significant landscape impacts in the western United States. Specifically, migratory wildlife populations have increasingly been impacted by rural urban development and energy resource development. This research presents the application of agent-based modeling to explore how such impacts influence the characteristics of migratory animal movement, focusing on mule deer (Odocoileus hemionus) in Western Wyoming. This study utilizes complex adaptive systems and agent-based modeling frameworks to increase understanding of migratory patterns in a changing landscape and explores thresholds of interference to migration patterns due to increased habitat degradation and fragmentation. The agent-based model utilizes GPS-collar data to examine how individual processes lead to population-level patterns of movement and adaptation. The assessment incorporates elements from both human and natural systems to explore potential future scenarios for human development in the natural landscape and incorporates adaptive behaviors, as well as animal-movement ecology, in changing landscapes.

A indicação do consumo de itens alimentares provenientes de plantas de ciclo fotossintético C3 e C4 pela comunidade de aves pode contribuir na determinação do potencial de resiliência de remanescentes florestais em paisagens agrícolas. O presente estudo buscou avaliar a composição da dieta da comunidade de aves situadas em fragmentos florestais inseridos em paisagem agrícola da bacia do rio Corumbataí, SP, através do uso da ferramenta de isótopos estáveis. Oito remanescentes florestais foram selecionados a partir da análise da idade dos remanescentes, sendo quatro antigos (33 e 49 anos) e quatro recentes (3 e 11 anos), dispostos em igual proporção em unidades amostrais (16 km²), com pelo menos 70% de ocupação pela matriz (pasto ou cana-de-açúcar) e 10% de mata. Foram realizadas 12 repetições em cada remanescente, totalizando 96 coletas. Uma sequência de cinco redes de neblina ornitológicas (malha 32 mm, 12 m x 2,8 m), foi alocada na área nuclear de cada remanescente, permanecendo abertas por um período contínuo de quatro horas, a partir das primeiras horas da manhã, vistoriadas a cada 30 minutos. Amostras de penas foram coletadas para análise isotópica. 33 espécies foram analisadas isotopicamente. A porcentagem de C3 encontrada nos indivíduos de 11 espécies foi relacionada às métricas da paisagem (porcentagem de cana e pasto e porcentagem de mata ou área nuclear, taxa anual de mudança, perfil da curva de mudança florestal e idade média). 81 espécies pertencentes a 27 famílias foram identificadas em 979 capturas. As mais frequentemente capturadas no período foram B. hypoleucus (84,38%), A. galeata (83,33%) e P. mystaceus (71,88%). Não houve diferença estatística entre riqueza em comunidades situadas em pasto e cana ou entre remanescentes antigos e recentes. A similaridade entre as comunidades presentes em matrizes de pasto e cana foi de 50,62%, sendo de 48,15% comparando-se remanescentes florestais antigos e recentes. As análises isotópicas das 33 espécies evidenciaram diferenças no uso de recursos provenientes de plantas de ciclo fotossintético C3 e C4. 78,79% das espécies possuíam uma dieta média com mais de 70% de sua alimentação baseada exclusivamente no consumo de itens C3, 21,21% consumidoras de C3 e C4 e nenhuma espécie com média predominantemente de itens C4. A análise individual, porém, mostrou indivíduos de T. fuliginosus e B. flaveolus com predomínio de C4 em sua dieta. Dentre as 11 espécies, seis (A. galeata, A. flavirostris, B. flaveolus, L. euleri, T. coronatus e T. leucomelas) mostraram relação com as variáveis da paisagem testadas. A composição da dieta das espécies foi afetada principalmente pela idade média do remanescente, havendo divergência quanto ao padrão de resposta em relação ao tipo e a proporção da matriz na paisagem. Embora os fragmentos amostrados estejam em avançado grau de degradação, os resultados corroboram para a necessidade de manutenção destes remanescentes como forma de manter a biodiversidade de aves. / Information on the consumption of food items from plants of C3 and C4 photosynthetic cycle by a bird community can help determine the potential resilience of forest remnants in agricultural landscapes. This study assessed the diet composition of bird communities in forest fragments embedded in the agricultural landscape of the Corumbataí River basin, São Paulo State, Brazil, using stable isotopes. Eight forest fragments were selected based on their ages, being four classified as \"old\" (33 and 49 years of age) and four \"young\" (3 to 11 years of age), arranged in equal proportion in sample units (16 km²), with at least 70% of occupation by the matrix (pasture or sugarcane) and 10% of forest. We performed 12 repetitions in each remnant, totaling 96 sampling. A sequence of five ornithological mist nets (32 mm mesh, 12 m x 2.8 m) was allocated in the nuclear area of each remnant, remaining open for a continuous period of four hours, in the early morning hours. The nets were inspected every 30 minutes. Feather samples were collected for isotopic analysis. We analyzed isotopically 33 species. The percentage of C3 found in individuals of 11 species was related to landscape metrics (percentage of sugarcane and pasture and percentage of forest or nuclear area, mean annual forest change rate, forest change curvature profile and average age). We identified 81 species belonging to 27 families in 979 catches. The most frequently captured species were B. hypoleucus (84.38%), A. galeata (83.33%) and P. mystaceus (71.88%). There was no statistical difference for predominance between the communities in pasture and sugarcane or between old and young remnants. The similarity between the communities in pasture and sugarcane matrices was 50.62%, and 48.15% comparing old and young forest remnants. The isotope analysis of 33 species showed differences in the use of plant resources of C3 and C4 photosynthetic cycle. A total of 78.79% of species had a diet average over 70% of its food consumption solely based on C3 plants, 21.21% consumed C3 and C4 and no species showed predominant consumption of C4 plants. Individual analysis, however, showed that T. fuliginosus and B. flaveolus predominantly consumed C4 plants. Among the 11 species studied, six (A. galeata, A. flavirostris, B. flaveolus, L. euleri, T. coronatus and T. leucomelas) showed a relationship with the landscape variables tested. Diet composition of species was mainly affected by the remnant average age, and results were different regarding the type and ratio of the landscape matrix. Although the fragments sampled are in advanced stage of degradation, the results corroborate the need to preserve these remnants to maintain biodiversity of birds.

Apesar da vasta literatura sobre os efeitos da perda e fragmentação florestal sobre a biodiversidade, poucos estudos incorporaram o aspecto temporal, ou seja, a história da paisagem, em suas análises. No entanto, o histórico de alterações da paisagem é um dos fatores que, ao ser ignorado, pode levar a interpretação errada dos reais efeitos da perda e fragmentação florestal sobre a diversidade de espécies. Assim, o objetivo desta tese foi avaliar os efeitos do histórico de mudança da paisagem sobre aves e pequenos mamíferos na Mata Atlântica. Para atingir este objetivo eu investiguei (1) a dinâmica de três paisagens fragmentadas de Mata Atlântica entre 1960-1980 e 1980-2000, (2) os efeitos da cobertura florestal passada e atual sobre a riqueza de espécies de espécies e, (3) a plausibilidade de modelos de cobertura vegetal nativa na riqueza de espécies e abundância, considerando ou não a heterogeneidade da vegetação nativa. Para investigar essas questões, foram usados dados de aves e pequenos mamíferos em 53 fragmentos florestais localizados em três paisagens com diferentes proporções de cobertura florestal (10, 30 e 50%) na Mata Atlântica do Planalto Atlântico de São Paulo. Os resultados mostraram que (1) a trajetória da cobertura florestal entre os anos 1960 e 2000 nas três paisagens estudadas foi não-linear e, atualmente, fragmentos florestais consistem de um mosaico de florestas com diferentes idades de regeneração, (2) a existência do débito de extinção e do crédito de espécies, assim como o potencial para o seu pagamento futuro, depende não só da trajetória de cobertura florestal, mas também da cobertura florestal remanescente na escala da paisagem, e (3) a heterogeneidade da vegetação nativa desempenha um papel importante na definição da riqueza de espécies e abundância e que as respostas a essa heterogeneidade são definidas pelos requerimentos de habitat e dependem de cobertura florestal da paisagem. / Despite the extended literature on the effects of forest loss and fragmentation on biodiversity, few studies incorporated the temporal aspect, i.e. the history of change of habitat amount and configuration over time at a given landscape, in the analysis. However, ignoring landscape change history might lead to inaccurate interpretation of the impact of forest loss and fragmentation on species diversity. Thus, the aim of this thesis was to evaluate the effects of landscape change history on birds and small mammals in the Atlantic Forest. To achieve this aim I investigated (1) the land-use and land-cover change dynamics in Atlantic Forest fragmented landscapes between 1960s-1980s and 1980s-2000s, (2) the effects of historical and present-day forest cover on species richness and, (3) the potential of explaining species richness and abundance patterns by inclusion or exclusion of present native vegetation heterogeneity in model frameworks. To address these objectives I used data on birds and small mammals in 53 forest fragments from three landscapes with different proportions of forest cover (10, 30 and 50%) in the Atlantic Forest of Brazil. The results showed that (1) forest cover trajectory between the 1960s and 2000s at the three study landscapes was non-linear and that individual forest patches currently consist of a mosaic of different forest age classes, (2) the existence of extinction debt and species credit as well as the potential for their future payment depends not only on forest cover trajectory but also on the present amount of remaining forest cover at the landscape scale, and (3) the heterogeneity within native vegetation plays an important role in defining species richness and abundance in fragmented landscapes and responses to this heterogeneity are defined by habitat requirements and depend on forest cover at landscape scale.

Past extensive changes in land use have resulted in fragmentation of species habitats. Changes in landscape structure have provoked discussion about the prospects of species of fragmented habitats in the future agricultural landscape. Landscape dynamics of plant species is basically a result of extinction and colonization rates. Many studies have confirmed the former expectation that a number of habitats suitable for a plant species in a landscape stay unoccupied. The differences in species distribution and proportion of suitable habitats occupied by a given species are hypothesized to be due to the area and isolation of suitable habitats and colonization and survival ability of a given species. To understand species dynamics in a changing landscape, first we have to reveal the relationships between the distribution of species and their proportion of occupied habitats, habitat age, habitat configuration and species colonization and survival ability. After the complete understanding of the determinants of species dynamics we will be able to predict reliably species prospect in the future. The very basic aim of this thesis was to reveal the determinants of landscape dynamics of dry grassland species in terms of their distribution and frequency in the landscape. The importance of correct identification...

<p>Land use and land cover changes significantly affect C storage in terrestrial ecosystems. Programs intended to compensate land owners for the maintenance or enhancement to C stocks are promising, but require detailed and spatially explicit C distribution estimates to monitor the effectiveness of management interventions. Savanna ecosystems are significant components of the global C cycle, however, they have not received much attention for the development of C monitoring approaches. In this dissertation I have investigated three of the aspects related to woody plant cover dynamics in semiarid savannas of central Argentina: spatio-temporal dynamics, precise field surveying and scaling from field to region with the use of freely available remotely sense data. </p><p>To examine the long term changes in woody plant cover, I first carefully extracted information from historical maps of the Caldenal savannas of central Argentina (190,000 km2) in the 1880s to generate a woody cover map that was compared to a 2000s dataset. Over the last ~120 years, woody cover increased across ~12,200 km2 (14.2 % of the area). During the same period, ~5,000 km2 of the original woody area was converted to croplands and ~7,000 km2 to pastures, about the same total land area as was affected by woody plant encroachment. A smaller area, fine scale analysis between the 1960s and the 2000s revealed that tree cover increased overall by 27%, shifting from open savannas to a mosaic of dense woodlands along with additional agricultural clearings. Statistical models indicate that woody cover dynamics in this region were affected by a combination of environmental and human factors.</p><p>To assess the consequences of woody cover dynamics on C, we also measured ecosystem C stocks along a gradient of woody plant density. I characterized changes in C stocks in live biomass (woody and herbaceous, above- and belowground), litter, and soil organic carbon (to 1.5 m depth) pools along a woody plant cover gradient (0 to 94 %). I found a significant increase in ecosystem C stocks with increasing woody cover, with mean values of 4.5, 8.4, 12.4, and 16.5 kg C m-2 for grasslands, shrublands, open and closed forests, respectively. Woody plant cover and soil silt content were the two primary factors accounting for the variability of ecosystem C. I developed simple regression models that reliably predict soil, tree and ecosystem C stocks from basic field measurements of woody plant cover and soil silt content. These models are valuable tools for broad scale estimation if linked to regional soil maps and remotely sensed data, allowing for precise and spatially explicit estimation of C stocks and change at regional scales.</p><p>Finally, I used the field survey data and high resolution panchromatic images (2.5 m resolution) to identify tree canopies and train a regional tree percent cover model using the Random Forests (RF) algorithm. I found that a model with summer and winter tasseled cap spectral indices, climate and topography performed best. Sample spatial distribution highly affected the performance of the RF models. The regression model built to predict tree C stocks from percent tree cover explained 83 % of the variability, and the spatially explicit tree C model prediction presented an root mean squared error (RMSE) of 8.2 tC/ha which represented ~30% of the mean C stock for areas with tree cover. Our analysis indicates that regionally over the last ~120 years, increases in woody plant cover have stored significant amounts of C (95.9 TgC), but not enough to compensate for in C generated by the conversions of woodlands and natural grasslands to croplands and pastures (166.7 TgC), generating a regional net loss of 70.9 TgC. C losses could be even larger in the future if, as predicted, energy crops would trigger a new land cover change phase in this region.</p> / Dissertation

En réponse aux incitations juridiques et à l’attente sociale, le renforcement de la dimension paysagère dans lagouvernance territoriale est incontestable avec la multiplication de projets, d’atlas, de plans, de chartes de paysage. Aumême titre que les autres outils, les Observatoires Photographiques du Paysage (OPP) se multiplient en Europe etparticulièrement en France depuis une vingtaine d’années. Néanmoins, ils peinent à être légitimés par les élus, experts,concepteurs et gestionnaires du territoire, ce qui est notamment dû au fait que les OPP sont difficilement exploitables,tant pour des difficultés d’accès que des problèmes de méthode.À partir d’un ancrage en géographie sociale, la thèse interroge les OPP à travers trois orientations : (i) leurs potentialitésà enrichir la connaissance sur les dynamiques paysagères et les représentations sociales des acteurs du territoire, (ii)leurs capacités à interagir avec les documents territoriaux, (iii) leurs aptitudes à être des supports de médiation entreles acteurs du territoire lors de projets de territoire.Les travaux de recherche sont menés dans la région Bretagne, où quinze structures locales portent un OPP. Via uncorpus choisi, diverses méthodes sont expérimentées et permettent d’entrecroiser les analyses : analyse descriptive ducontenu visuel OPP, analyse du discours des acteurs du territoire à partir d’enquêtes par entretien, analyse comparativeentre les OPP et les documents territoriaux. Dans une perspective de recherche-action, un travail collaboratif avec lesstructures locales OPP a conduit à la création d’une Plateforme informatique, la POPP-Breizh. Cette dernière apportedes solutions pour rendre accessible et exploitable les OPP.In fine, la présente recherche évalue les capacités des OPP à répondre aux enjeux sociétaux et scientifiques actuelsliés au paysage afin d’élaborer des préconisations pour que les OPP deviennent des archives intégrées à lagouvernance territoriale. / In response to legal incentives and social expectations, the reinforcement of the landscape dimension in territorialgovernance is undeniable, in light of the growing number of landscape projects, atlases, plans and charters. Alongsideother tools, an increasing number of photographic landscape observatories have been emerging in Europe andparticularly in France over the past twenty years. These observatories however are struggling to become legitimised bylocal councillors, experts, land designers and land managers, notably based on the fact that these observatories aredifficult to exploit, both due to access difficulties and method-related issues.Based on a foundation of social geography, this thesis examines photographic landscape observatories from threepoints of view: (i) their potential to enrich knowledge of landscape dynamics and social representations of localstakeholders, (ii) their capacity to interact with territorial documents, (iii) their ability to act as mediation aids betweenlocal stakeholders for land development projects.The research work was carried out in the French region of Brittany, where fifteen local organisations host a photographiclandscape observatory (or OPP). Through a chosen corpus, various methods were tested and could be used for crossingdifferent types of analysis: descriptive analysis of the observatory's visual content, discourse analysis of localstakeholders from individual interviews, comparative analysis between observatories and territorial documents. With aview to action research, collaborative work with local OPPs has led to the creation of a computer platform dubbed POPPBreizh.This platform provides solutions to make OPPs accessible and usable.Finally, this research assessed the capacity of OPPs to meet current societal and scientific challenges relating to thelandscape in order to develop recommendations to enable OPPs to become archives integrated within territorialgovernance.

No description available.