No / International Joint Ventures (IJVs) have become one of the most important ways for companies to expand their activities and exploit business opportunities abroad. In China, for example, which has become the world's largest recipient of Foreign Direct Investment, IJVs with local companies are the most important way of doing business. However, many companies have learnt that the performance of their joint ventures in China does not meet their expectations. This study focuses on functional diversity - differences in business practices between foreign and local companies - and its influence on IJV performance. We investigate the influence of this functional diversity on the performance of IJVs and discuss how companies can moderate this influence through adaptation, trust, commitment and communication. Hypotheses are formulated and empirically tested using data gathered through a questionnaire survey of managers of German-Chinese IJVs. The results show that although functional diversity has a negative impact on IJV performance, managers can influence the magnitude of this impact. We use insights from interviews with managers of German-Chinese IJVs in China to supplement our discussion and provide some indication of best practice.

Subalpine ecosystems are experiencing rapid changes in snow pack, temperature, and precipitation regime as a result of anthropogenic climate forcing. These changes in climate can have a profound effect on subalpine ecosystem structure and functioning, which may ultimately feed back to climate change. In this study, I examined the response of the subalpine meadow plant communities at the Rocky Mountain Biological Laboratory to natural and simulated climate change. First, I looked at whether changes in growing season precipitation or temperature regime would have the larger effect on subalpine ecosystem carbon flux. In a simulated warming experiment, changes in growing season precipitation had a tenfold larger effect on cumulative carbon flux than did the warming treatment. Along a natural climatic and elevational gradient, precipitation stimulates carbon uptake, particularly at higher elevations. Given projected decreases in summer precipitation in the high elevation Rockies, we predict a 20% decrease in carbon uptake from subalpine meadows. Second, I compared the taxonomic, phylogenetic and functional structure of plant communities along an elevational gradient to infer which climatic and biotic factors influence community assembly at each elevation. Floral and phenology traits become overdispersed at high elevation, mirroring phylogenetic relatedness, and suggesting pressure to diversify to attract pollinators during the abbreviated growing season. At the same time, leaf functional traits become clustered at high elevation, indicating multiple opposing assembly mechanisms in subalpine communities. Finally, I studied the natural history of sagebrush, Artemisia tridentate ssp. vaseyana, at its elevational range limit in subalpine meadows. In particular, I focused on the importance of warming and species interactions in elevational advance of the species. I found that facilitation by neighboring forbs was critical for sagebrush seedling survival, decreasing mortality by 75%. Seedling mortality was overwhelmingly due to desiccation of seedlings; therefore, neighboring forbs moderate temperature and water stress for seedlings. Despite the extremely limited growing season at high elevation caused by subfreezing temperatures, subalpine ecosystem structure and function are closely tied to water availability during the growing season. Therefore, improved predictions of future precipitation regimes over the Rocky Mountains will be our best tool for conservation of these fragile habitats.

The role that perceived information quality has on the intention to use a computer supported collaborative work (CSCW) system in the Federal Highway Administration is the focus of this study. The purpose of this study was to examine the functional diversity of the contributors in a CSCW as a major determinant of perceived information quality. The study relied on the Technology Acceptance Model (TAM), the Theory of Reasoned Action (TRA) and the Theory of Planned Behavior (TPB) to propose a theoretical model which shows that perceived information quality influences perceived risk and trusting belief of the users of these systems. Both perceived risk and trusting belief shape the intention to use a computer supported collaborative work systems. This study conducted a web-based survey to validate the theoretical model. The study focused on the use of computer-supported collaborative work systems in the Federal Highway Administration. This study empirically validated the theoretical model. Scales were developed within the context of the variables (functional diversity, perceived information quality, perceived risk, trusting belief, and intention to use.) to survey discipline members at the Federal Highway Administration.The statistical results showed support for perceived information quality’s positive influence on trusting belief, perceived information quality’s negative influence on perceived risk, perceived risk’s negative influence on the intention to use a CSCW and trusting belief’s positive influence on the intention to use a CSCW. The results also showed there is no statistically significant difference in perceived information quality by functional diversity. This study concluded that the research model showed significant results to support four of the five hypotheses proposed and helped uncover key findings on how perceived information quality can be impacted. This research served as an original contribution to CSCW while working in functionally diverse teams environments.

No description available.

A expansão da fronteira agrícola leva à perda e à fragmentação do habitat natural, sendo estas as principais causas da perda de biodiversidade e de suas funções ecossistêmicas. Assim, o objetivo deste trabalho foi avaliar de que maneira as modificações na paisagem e na complexidade estrutural da vegetação se relacionam à diversidade funcional (DF) de aves em paisagens agrícolas. Foram realizados levantamentos em 20 fragmentos de floresta secundária, utilizando-se o método de ponto de escuta, totalizando 95 pontos amostrados por 10 minutos cada em três campanhas mensais. Foi calculada a riqueza funcional (FRic) das assembleias e a abundância de 14 grupos funcionais (GF), as quais por sua vez foram relacionadas à quatro atributos de estrutura e dinâmica da paisagem (conectividade, área total, proporção de área core e idade dos fragmentos) que compõem a abordagem de Potencial de Prestação de Serviços Ecossistêmicos (PPSE) proposta por Ferraz et al. (2014) para atribuir valores desse potencial a fragmentos em paisagens agrícolas. A FRic e abundância de GF foram relacionadas também à complexidade estrutural dos fragmentos (CEF), aqui estimada através da riqueza, densidade e área basal de indivíduos arbóreos registrados em parcelas de 900m2 em 12 dos 20 fragmentos estudados. Tais parâmetros de CEF foram submetidos a uma Análise de Componentes Principais (PCA), a partir da qual foram utilizadas as quatro primeiras componentes para as análises. As relações entre a DF de aves e atributos da paisagem e de CEF foram avaliadas por meio da seleção de Modelos Lineares Generalizados (GLM) e Modelos Aditivos Generalizados (GAM), utilizando-se para tal o Critério de Informação de Akaike corrigido para pequenas amostras (AICc), onde modelos com ΔAICc 0,1 foram considerados os mais plausíveis. FRic relacionou-se positivamente e de modo não linear à combinação de área e conectividade, onde fragmentos com tamanhos inferiores a 60-70 hectares e com distâncias superiores a 170 metros tiveram grande redução em seus valores. A presença de um sub-bosque desenvolvido também foi um fator importante para a promoção de uma maior FRic. GFs responderam diferentemente aos atributos de paisagem e de CEF, sendo que grupos de nectarívoros, granívoros, frugívoros e onívoros tolerantes à perturbação apresentaram, em sua maioria, relação negativa, enquanto frugívoros e insetívoros menos tolerantes e associados a microhabitats específicos responderam positivamente. Ainda, a maior parte dos GFs responderam à CEF e não aos atributos de paisagem, mostrando que parâmetros mais específicos das assembleias devem ser avaliados em uma escala ambiental também mais refinada. Tais resultados podem servir como diretrizes em políticas públicas para a manutenção de paisagens agrícolas funcionalmente diversas no que diz respeito às funções promovidas pela avifauna. Além disso, sugere-se que a abordagem de PPSE considere apenas área total e conectividade para ser utilizada também como um indicador da DF de aves em paisagens agrícolas. / The expansion of agricultural frontier leads to fragmentation and habitat loss, which are the main causes of biodiversity loss and its ecosystem functions. Therefore, the main goal of this work was evaluate how changes in landscape attributes and structural compexity of vegetation promoted by this expansion affect functional diversity (DF) of birds in agricultural landscapes. For this, surveys were carried out on 20 fragments of secondary forest, using the point-count method, totaling 95 points sampled for 10 minutes each in three monthly visits. Functional Richness (FRic) of recorded assemblages and the abundance of 14 functional groups (GF) were calculated, which in turn were related to four attributes of landscape structure and dynamics (connectivity, total area, core area ratio and age of fragments) that compose the Ecosystem Services Provisioning Potential (PPSE) approach proposed by Ferraz et al. (2014) to attribute values of this potential to fragments immersed in agricultural landscapes. In addition to these attributes, Fric and abundance of GF were also related to the structural complexity of the fragments (CEF), estimated here by richness, density and basal area of arboreal individuals recorded in 900m2 plots in 12 of the 20 fragments studied. These CEF parameters were summarized in a Principal Component Analysis (PCA), from which the first four components were used in analysis. The relationship between the DF of birds and landscape and CEF attributes were evaluated through Generalized Linear Models (GLM) and Generalized Admixtive Models (GAM) models\' selection, using Akaike Information Criterion corrected for small samples (AICc), where models with ΔAICc 0.1 were considered the most plausible. FRic was positively and non-linearly related to the combination of area and connectivity, where fragments smaller than 60-70 hectares and distances greater than 170 meters had a great reduction in its values. A well-developed understory was also an important factor in achieving greater values of FRic. GFs responded differently to landscape and CEF attributes, with groups of nectarivores, granivores, frugivores and omnivores tolerant to the disturbance presenting a negative relationship, whereas frugivores and insectivores less tolerant and associated to specific microhabitats responded positively. Nevertheless, most GFs responded to CEF rather than landscape attributes, showing that more specific parameters of assemblages should be evaluated on a more refined environmental scale. Such results can serve as guidelines in public policies for the maintenance of functionally diverse agricultural landscapes with respect to the functions promoted by avifauna. In addition, it is proposed that the PPSE approach consider only total area and connectivity to be used as an indicator of birds\' DF in agricultural landscapes.

Os ecossistemas campestres que caracterizam os Campos Sulinos contêm alta biodiversidade e a sua manutenção está associada aos regimes de distúrbio como o fogo e o pastejo. Apesar de sua ampla contribuição social, nas últimas décadas esses ecossistemas têm sido substituídos por lavouras anuais e silvicultura, em razão de uma suposta vantagem econômica em relação à pecuária. Portanto, urge a consolidação de estratégias de manejo que conciliem a manutenção da diversidade biológica, dos processos ecossistêmicos e dos serviços ecológicos, com a viabilidade econômica aos produtores. Neste sentido, esta tese pretende colaborar com a concepção de estratégias de manejo para distintas formações dos Campos Sulinos. No Capítulo 1 discutimos a perspectiva de manejo adaptativo para a conservação de mosaicos de campos e florestas, propondo alternativas para serem testadas. Os Capítulos 2 e 3 abordam respostas das comunidades de plantas às três estratégias de manejo implementadas em um experimento conduzido em Aceguá/RS. No Capítulo 2 tratamos das mudanças na diversidade funcional e na estratégia de utilização dos recursos pelas plantas em resposta às estratégias de manejo. Em três escalas espaciais estudadas houve efeitos significativos dos diferentes manejos avaliados, incluindo o tratamento controle definido pelo manejo adotado na propriedade. No Capítulo 3 tratamos do efeito da roseta espinhenta Eryngium horridum sobre as comunidades de plantas, em resposta a um gradiente de altura da vegetação e aos dois sistemas de manejo conservativos implementados. Mesmo em uma pequena escala de tempo, neste estudo tivemos uma amostra da produção secundária dos campos de solos profundos e das respostas das comunidades de plantas às diferentes estratégias manejo aplicadas. / The Southern Brazil grassland ecosystems (Campos) contain high biodiversity and their maintenance is related to disturbance regimes as fire and grazing. Despite their contribution to society, in the last decades these ecosystems have been converted to crops and tree plantations due to the alleged economic advantage compared to livestock farming on the native grasslands. Therefore, it is urgent to consolidate management strategies that could combine the maintenance of biological diversity, ecosystem processes and ecological services, with economically viable livestock farming. In this sense, this thesis intends to collaborate with the design of management strategies for distinct grassland formations of the South Brazilian Campos. In Chapter 1 we discuss the concept of adaptive management as applied to grassland/forest mosaics that characterize southern Brazil formations, and propose management options to be tested. In Chapters 2 and 3 we refer to the responses of plant communities to three grazing management treatments implemented in an experiment conducted in Aceguá/RS. In Chapter 2 we investigated changes in plant functional diversity and resource use strategies in response to three grazing managements. At the three studied spatial scales we found differences between rotational grazing and the management used in farm. Finally, in the chapter 3 we study the effect of thorny rosette Eryngium horridum in plant communities, in response to the vegetation height gradient and the two conservative grazing managements. Even in a short time, in this work we verify the first results of the secondary production and the responses of plant communities to the applied management strategies.

A expansão da floresta sobre o campo, a partir do estabelecimento de araucárias isoladas (nucleação), forma uma paisagem única no planalto sul-brasileiro, sendo que o uso de uma abordagem de metacomunidades pode auxiliar a compreender melhor esse processo. Existem quatro modelos de metacomunidades que explicam a relação entre comunidades locais: dinâmica de manchas, seleção de espécies, efeitos de massa e neutro. Esses modelos possuem diferentes premissas quanto aos processos de nicho e de dispersão que atuam na dinâmica da metacomunidade. No entanto, há uma lacuna entre a teoria e o teste desses modelos em estudos empíricos. Uma forma de testar mais claramente esses modelos é através de uma abordagem funcional. Nesse contexto, o objetivo do trabalho foi avaliar a importância (i) de atributos relacionados às estratégias de dispersão e de crescimento das espécies, (ii) da abundância das espécies no pool regional e (iii) do tamanho da mancha, na organização de comunidades de indivíduos lenhosos juvenis em áreas de nucleação florestal sobre o campo, a fim de compreender quais modelos de metacomunidades melhor explicam esse processo. Para tanto, calculamos o CWM (Community Weighted Mean) e índices de diversidade funcional, considerando a ocorrência (sesFD) e a abundância (sesFDis) das espécies, para tamanho da semente e área foliar específica (SLA), em manchas florestais de distintos tamanhos e na floresta contínua adjacente ao campo, e testamos se as áreas diferem entre si de acordo com o tipo de ambiente. Avaliamos ainda se a abundância relativa das espécies nas áreas de nucleação é determinada pela abundância das mesmas na floresta contínua, através do uso dos modelos de Community Assembly by Trait Selection (CATS). Os resultados foram então comparados com o esperado para cada modelo de metacomunidade. A maior parte dos sítios apresentou índices de diversidade funcional para SLA e tamanho da semente de acordo com o esperado ao acaso. As áreas não diferiram quanto ao CWM para SLA. No entanto, foram observadas diferenças quanto ao CWM para o tamanho da semente, com o favorecimento de espécies com sementes menores em áreas mais abertas, e espécies com sementes maiores em áreas mais sombreadas. De acordo com os modelos CATS, a abundância das espécies no pool regional foi mais importante do que os atributos para a determinação da abundância das mesmas nas comunidades locais. Concluiu-se que o modelo de metacomunidades que melhor explica o processo de nucleação florestal sobre o campo no planalto das araucárias é o modelo de efeitos de massa, o que ressalta a importância da dispersão para a estruturação das comunidades locais. Como a maior parte das espécies lenhosas existentes na área possui dispersão zoocórica, esse resultado indica que a preservação da fauna dispersora é fundamental para a dinâmica desse ecossistema. Com o uso de uma abordagem funcional, em conjunto com os modelos CATS, foi possível testar os quatro modelos de metacomunidades. Assim, o método proposto pode ser aplicado a outros sistemas naturais, auxiliando na compreensão do funcionamento de diferentes metacomunidades. / The forest expansion over the grassland, from the establishment of isolated Araucaria (nucleation) forms a unique landscape in south brazilian plateau, and the use of a metacommunity approach can help to better understand this process. There are four metacommunity models that explain the relationship between local communities: patch-dynamics, species-sorting, mass-effects and neutral. These models have different assumptions about niche processes and dispersion that act in metacommunities dynamics. However, there is a gap between theory and the test of these models in empirical studies. One way to test these models more clearly is through a functional approach. In this context, the objective of this study was to evaluate the importance of (i) attributes related to dispersion and growth species strategies, (ii) species abundance in the regional pool and (iii) patch size, on structuring communities of juvenile woody individuals in forest nucleation areas on the grassland in order to understand which metacommunity model explain this process. Therefore, we calculate the CWM (Community Weighted Mean) and functional diversity indices, considering species occurrence (sesFD) and abundance (sesFDis) for seed size and specific leaf area (SLA), in forest patches of different sizes and in adjacent continuous forest and tested if sites differ according to ambient. Further, we evaluated if species relative abundance in nucleation areas is determined by the abundance in the continuous forest, by the use of Community Assembly by Trait Selection (CATS) models. Then, we compared results with expected for each metacommunity model. Most of sites presented functional diversity values for SLA and seed size as expected by chance. Areas did not differ in CWM to SLA. However, we observed differences for CWM to seed size, favoring species with smaller seeds in more open areas, and species with larger seeds in more shaded areas. According to CATS models, species abundance in regional pool was more important than attributes to determine species abundance in local communities. We concluded that the metacommunity model that best explains forest nucleation on the grassland in Araucaria plateau is the mass-effects model, which emphasizes the importance of dispersion for structuring local communities. As most of existing woody species has zoochorous dispersion, this result indicates that preservation of disperser fauna is essential for ecosystem dynamic. By using a functional approach in combination with CATS models, it was possible to test the four metacommunity models. Thus, the method proposed in this work can be applied to other natural systems, helping understanding different metacommunities operation.

Ecólogos de comunidades têm como um dos principais objetivos identificar padrões de abundância e distribuição de espécies ao longo das regiões e ambientes, e inferir sobre os processos norteadores desses padrões. Para tanto, duas linhas teóricas complementares são principalmente utilizadas: limitação de similaridade e filtros ambientais. Enquanto a primeira prediz que as espécies dentro de uma comunidade devem ser distintas nas suas características como resultado da competição (divergência), a segunda espera uma alta similaridade entre espécies coexistentes (convergência), uma vez que elas são filtradas sob certas condições ambientais. Estudos sobre diversidade funcional podem nos dar uma ideia da proporção de divergência e convergência na estruturação das comunidades, enquanto a composição funcional pode indicar a direção das respostas funcionais aos filtros ambientais. Ambientes campestres predominantemente cobrem o bioma Pampa, no sul do Brasil, e nesta região as florestas são restritas a zonas ribeirinhas e a pequenas encostas. As inundações são uma pressão comum em matas ribeirinhas, mas dadas as condições da região elas também são vulneráveis à dessecação por evapotranspiração e ventos. Em contraste, as florestas de encosta são mais sombreadas e úmidas. No presente trabalho, temos como objetivo principal caracterizar a diversidade e composição funcional destes ambientes florestais. Esperamos encontrar padrões de convergência para os atributos de florestas ciliares, devido às condições ambientais mais severas. Estabelecemos 18 unidades amostrais de 250 x 10 m em três regiões do Pampa, nove para cada tipo de floresta. Todas as árvores com pelo menos 5 cm de DAP (diâmetro à altura do peito) foram medidas. As regiões representam um gradiente de precipitação e temperatura. Seis atributos funcionais das espécies arbóreas foram avaliados: área foliar, área foliar específica (SLA), conteúdo de matéria seca foliar (LDMC), altura máxima, síndrome de dispersão e tamanho do fruto. Índices de diversidade funcional e seus tamanhos de efeito padronizados (SES - standardized effect size) dada a riqueza local de espécies foram estimados para cada região e tipo florestal. A composição funcional foi analisada através de média dos atributos funcionais ponderada pelas abundâncias nas comunidades (CWM), com posterior análise de variância para verificar diferenças entre as florestas e regiões. Os valores de CWM de área foliar e proporção de zoocoria foram menores nas florestas ribeirinhas de todas as regiões, enquanto o tamanho do fruto, SLA e LDMC só foram influenciados pelo fator região, sendo a SLA menor na região de menor precipitação e temperatura médias anuais. Altura máxima média das comunidades diferiu tanto conforme o tipo de floresta (maior na encosta) quanto à região (maior na região com condições climáticas mais favoráveis). Os valores do SES para riqueza funcional e dispersão funcional não demostraram padrões de divergência ou convergência significativos. Apenas a riqueza funcional para altura e tamanho de fruto foi distinta de acordo com o ambiente e a região das florestas avaliadas. Os resultados deste trabalho, ao contrário do esperado, demonstram não haver padrões de divergência e/ou convergência funcional para as florestas do Pampa, em termos do ambiente em que ocorrem (ciliar ou encosta) ou mesmo região. Contudo, a composição funcional variou tanto em relação ao ambiente quanto à região. Isso pode indicar uma seleção de espécies com distintas estratégias adaptativas de acordo com as diferentes influências ambientais em escala local e regional. / Community ecologists aim at identifying patterns of species abundance and distribution along regions and environments, inferring on their main driver processes. Two complementary approaches rule community assembly: limiting similarity and environmental filters. While the first predicts that species within a community should be distinct in traits to avoid competition (divergence), the second expects a high similarity between co-occurring species (convergence), since they are filtered out to occur under certain environmental conditions. Functional diversity can give us an idea of the proportion of divergence and convergence in the structure of communities, while the functional composition might indicate the direction of trait responses to the environmental filters. Grasslands predominantly cover the southern Brazilian Pampa, and the forests are restricted to riparian zones and hillslopes. Flooding is a common pressure on riparian forests, but given the environmental conditions of the region they are also vulnerable to desiccation by evapotranspiration and winds. In contrast, slope forests are more shaded and humid. We aimed at characterizing functional diversity and composition of these forest environments. We expected trait convergence for riparian forests because of the harsher environmental conditions. We established 18 sampling units of 250 x 10 m in three regions of the Pampa, nine for each forest type. All trees with at least 5cm DBH were measured. The regions represent a gradient in precipitation and temperature. Six functional traits of the tree species were assessed: leaf area, specific leaf area (SLA), leaf dry matter content (LDMC), plant height, dispersal mode, and fruit size. Functional diversity indices and their standardized effect size (SES), considering the local species richness, were estimated for each region and forest. Functional composition was analyzed through community-weighted mean of traits (CWM), with further analysis of variance to verify differences between forests and regions. CWM of leaf area and zoochory were lower in riparian forests of all regions, while fruit size, SLA and LDMC were only influenced by the region. SLA was lower in the region with lower annual mean precipitation and temperature. Maximum height shows response for the type of forest (higher CWM in hillslope forests) and region (higher in the region under more favorable climatic conditions). SES of functional richness and dispersion did not show a recurrent pattern of significant divergence or convergence related to the factors. The results of SES, contrary to our expectation, are not indicating any patterns of trait divergence and/or convergence for the forests. Only the functional richness of height and fruit size differed according to the habitat and the region of the studied forests. However, both forest environments and regions differed in terms of functional composition, indicating the assembling of species with distinct adaptive strategies in relation to different environment influences for local and regional scale.

L’intérêt que porte la communauté scientifique ainsi que politique aux les services écosystémiques et à leur résilience face aux changements globaux (environnementaux ou sociétaux) en cours est grandissant, ce qui se reflète par le nombre d’études à ce sujet, le rapport d’évaluation des écosystèmes pour le millénaire et la mise en place d’un groupe de travail sur la résilience (« Resilience Alliance »). Les définitions de la résilience sont elles aussi très variées, avec des concepts tels que la résistance, la résilience spécifique (« de quoi à quoi ? »), la résilience générale, l’adaptabilité et la transformabilité, que nous nous sommes appropriés dans le but de développer un cadre conceptuel et méthodologique pour étudier la résilience de la fourniture de services écosystémiques, en particulier dans le but de comparer les potentiels de résilience des différents types de prairies subalpines du col du Lautaret (Hautes-Alpes, France) pour un ensemble de services sélectionnés. Nous avons proposé deux approches pour évaluer les potentiels de résilience des différents états dans lequel peut se trouver un socio-écosystème, en considérant la résilience comme la capacité d’un système à maintenir une fourniture stable de services écosystémiques (composante résistance) mais aussi sa capacité à l’adapter (différentes composantes selon le degré d’adaptation : résilience, transition, transformation). Une première étape d’évaluation d’un ensemble de services d’intérêt sur la zone d’étude est suivie d’une première analyse de la résilience de chacun de ces services spécifiquement, basée sur l’évaluation de « gammes opérationnelles » pour chaque service, définies comme les gammes de valeurs que peut prendre le dit service dans un état donné du socio-écosystème. L’échelle organisationnelle à laquelle ces gammes sont évaluées les relie aux différentes composantes de la résilience. Les résultats confirment l’intérêt de s’intéresser à la résilience spécifique de chaque service, car leur profil de résilience sont différents, c’est-à-dire que les prairies aux plus forts potentiels ne sont pas les même d’un site à l’autre, bien que dans tous les cas les potentiels de résilience soient plutôt forts, au contraire des autres potentiels.La deuxième analyse part de l’hypothèse théorique que la diversité des traits de réponse (hétérogénéité et redondance) améliore la résilience. Nous avons fait l’hypothèse que, lorsque les traits de réponse sont ceux utilisés pour modéliser les services écosystémiques, la diversité fonctionnelle d’une communauté végétale peut-être reliée à sa résilience générale en termes de services écosystémiques. Nous avons relié plusieurs mesures de la diversité fonctionnelle aux potentiels de résilience (entropie et diversité fonctionnelle dans leur dimension α et β, redondance et complémentarité des groupes fonctionnels). Cependant, les résultats obtenus par l’analyse des prairies du Lautaret nous amènent à réfuter l’hypothèse proposant que la diversité fonctionnelle des communautés végétales permet d’expliquer le profil de résilience des services écosystémiques analysés, car ils ne concordent pas avec les profils de résilience trouvés par l’approche des gammes opérationnelles. Au final, nous préconisons d’utiliser l’approche des gammes opérationnelles, qui permet de connaître le profil de résilience de chaque service, dans le cadre d’étude portant sur la capacité d’un socio-écosystème à maintenir la fourniture de ses services écosystémiques. Cette approche peut de plus être enrichie d’une approche de scénarisation qui permettrait de déterminer « à quoi » la fourniture de chaque service est résiliente. / As evidenced by the number of studies on the subject, the recent millennium ecosystem assessment and the establishment of a working group on resilience (« Resilience Alliance »), the interest of the scientific community in ecosystem services and their resilience in the face of global change (environmental or social) is steadily increasing. Definitions of resilience are highly varied, and we used concepts such as resistance, specific resilience (« of what to what ? »), generalised resilience, adaptability and transformability to develop a conceptual and methodological framework to study the resilience of ecosystem service provision. This conceptual framework was applied to compare the potential resilience of differing sub-alpine grasslands types in three local government areas in the area of the Col du Lautaret (Hautes-Alpes, France) for a number of locally and regionally important ecosystem services. We proposed two approaches for evaluating the potential resilience of the different states in which a socio-ecosystem can exist, by considering resilience as the capacity of a system to maintain a stable provision of an ecosystem service (resistance component), as well as its capacity to adapt this provision if needed (components of resilience, transition, transformation depending on the degree of adaptation). A first stage of the quantification of ecosystem services was followed by an initial analysis of each of these services via the evaluation of their « operating ranges », defined as the range of values that a service can take given a particular state of the socio-ecosystem. The organizational scale at which these ranges are evaluated links them to other components of resilience. Our results confirm the utility of considering the specific resilience of each service, as the profiles of their resistance are different. In particular, the types of grasslands with the highest resilience component potential are not the same from one site to another, even though in all cases these resilience component potentials are rather high as compared to other components potentials. The second analysis is based on the theoretical hypothesis that it is the increasing diversity of response traits (heterogeneity and redundancy) which increases resistance. We hypothesised that, when it is response traits that have been used to model ecosystem services, the functional diversity of a plant community can be linked to its overall resistance in terms of ecosystem services. We linked a number of measures of functional diversity to resilience potential, including the α and β dimensions of entropy and functional diversity, and the redundancy and complementarity of functional groups. The obtained results for the grasslands at Lautaret lead us to reject the hypothesis which proposes that the functional diversity of plant communities can be used to predict the patterns of resilience of the analysed ecosystem services, as these do not correspond to the patterns of resistance obtained from the approach using operating ranges. Finally, we suggest that to assess the capacity of a socio-ecosystem to maintain the provision of ecosystem services, our approach using operating ranges is preferable as it allows for the quantification of the resistance profile of each service. This approach could be further developed using scenario building so as to determine « to what » the provision of each service is resistant.

Orientador: Felipe Wanderley Amorim / Resumo: As mudanças globais mediadas pela ação antrópica estão alterando a biodiversidade e os ecossistemas em um ritmo acelerado. Um dos principais impulsionadores dessas mudanças é a introdução de espécies exóticas em ecossistemas nativos. Entre os grupos de organismos afetados por este processo, o das plantas é reconhecido um dos mais preocupantes, uma vez que a produção primária limita o tamanho e a composição das comunidades e participa através de efeitos em cascata em interações multi-tróficas. Uma das principais relações ecológicas influenciada por esse efeito é a relação entre plantas e polinizadores, cujo papel é importante para estrutura e funcionamento das comunidades biológicas, não apenas porque as plantas fornecem recursos alimentares essenciais para muitos grupos de animais que visitam flores, mas também porque o sucesso reprodutivo da maioria das plantas com flores depende dos serviços bióticos fornecidos por estes animais. Neste contexto, a introdução de espécies de plantas exóticas invasoras pode ter impactos críticos nas interações planta-polinizador ao nível da comunidade, principalmente através da competição com espécies nativas. Como as interações planta-polinizador são cruciais para determinar a estrutura da comunidade, nesse estudo nós testamos como o crescimento rápido de uma gramínea invasora altera a composição das espécies de plantas nativas em um campo cerrado, juntamente com os impactos deste processo sobre a estrutura das interações planta-polinizador. ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The global change mediated by anthropic action is altering biodiversity and ecosystems in a fast pace. One major driver of these changes is the introduction of alien species in native ecosystems. Among the groups of organisms that are affected by this process, plants are recognized to be one of the most concern, since primary production limit global communities’ sizes and composition, and participate through cascade effects on multitrophic interactions. One crucial type of interaction that is influenced by this effect is the plant-pollinator relationship, which have an important role in the structure and functioning of biological communities, not only because plants provide essential food resources for many groups of animals that visit flowers, but also because the reproductive success of most flowering plants depends on the biotic services provided by animals. In this context, the introduction of invasive alien plant species may have critical impacts on plant-pollinator interactions at community level, mainly through competition with native species. Since plantpollinator interactions are determinants of community structure, here we evaluated how the rising of a fast-growing invasive alien grass species changes plant species composition of a Neotropical grassland community along with its impacts on the structure of plant-pollinator interactions. For this, we analyzed the changes in community composition and plantpollinator interactions over time, through the temporal turnover... (Complete abstract click electronic access below) / Mestre