Les changements climatiques et leurs effets sur la forêt méditerranéenne : aspects génétiques -

Que peuvent faire les arbres forestiers et leurs écosystèmes en réponse aux changements climatiques qui s'installent sur la longue durée ? Comme tous les organismes vivants, ils peuvent mettre en place trois grandes stratégies : s'acclimater, s'adapter et/ou fuir. Dans cet article, l'auteur nous décrit les différents mécanismes d'adaptation génétique et propose de réfléchir à des pratiques sylvicoles permettant une gestion adaptative de la forêt méditerranéenne

Modelación Integrada de Sistemas Socio-ecológicos Complejos: Caso de Estudio la Ecorregión de la Mojana

Context: It was observed that the modeling of complex socio-ecological systems based on Agent-Based Simulations has the advantage of allowing the integration of different processes, scales, variables and the possibility to generate scenarios with actors in the context of the modeling with stakeholders.Method: A computational tool for planning and support of decision-making processes related with water resources management, specifically in the case of floods in the Mojana ecoregion (Colombia) is designed along with social participation workshops related with beliefs, values, social networks and resilience.Results: The model has two components: the first one represents the hydrodynamic of flooding by means of the numerical platform ISIS 2D. The second one, regarding the social aspects of the region, is handled via agent systems modeling. Both schemes are integrated into the NetLogo platform.Conclusions: The integrated modeling of complex socio-ecological systems allow us to visualize the behavior of the population and the natural resources in a territory, contributing to the design of policies and educational processes involving different disciplines and actors. Future work will focus on regional modeling and the analysis of the impact produced by the use of these tools.Contexto: Se ha observado que la modelación de sistemas socio-ecológicos complejos a partir de simulaciones basadas en agentes, tienen la ventaja de integrar diferentes procesos, escalas, variables y la posibilidad de generar escenarios con actores en el marco de procesos de modelación participativa.Método: Se diseña una herramienta computacional para la planificación y apoyo a los procesos de toma de decisión relacionados con la gestión de los recursos hídricos, específicamente para el caso de las inundaciones en la ecorregión de la Mojana (Colombia). Son desarrollados talleres de participación social relacionados con creencias, valores, redes sociales y resiliencia.Resultados: El modelo tiene dos componentes: el primero representa la hidrodinámica de las inundaciones por medio de la plataforma numérica ISIS 2D; el segundo, en relación con los aspectos sociales de la región, se maneja a través de modelado de sistemas de agentes. Ambos sistemas están integrados  en la plataforma NetLogo.Conclusiones: La modelación integrada de sistemas socio-ecológicos complejos permite visualizar el comportamiento de la población y los recursos naturales en un territorio, contribuyendo al diseño de políticas y los procesos educativos con la participación de diferentes disciplinas y actores. Trabajos futuros, pueden enfocarse en la modelación regional y el análisis del impacto producido por el uso de estas herramientas. 

Addressing biodiversity in plantation forests management in northwestern Portugal

Doutoramento em Engenharia Florestal e dos Recursos Naturais / Instituto Superior de Agronomia. Universidade de LisboaBiodiversity is important for forest ecosystem health maintenance and sustainable functioning and therefore its conservation is significant in all types of forests, including plantations. The Mediterranean region is known as a biodiversity ‘hotspot’, but also as an area with recently established forest plantations, that are criticized for the low level of biological diversity and frequent forest fires. Therefore, including biodiversity assessment in forest plantations management planning might benefit forest conservation, fire prevention and land some novel ecosystem services. Here we attempted to investigate: (1) which biodiversity indicators could be considered in forest management planning, (2) how to assess and what is the state of biodiversity at a stand level in plantation forests of northwestern Portugal, (3) how to use stand-level indicators to assess landscape biodiversity aspects in plantation forests in northwestern Portugal? Results demonstrated that: (1) the most convenient for forest managers with various backgrounds is to consider structural indicators in integrating biodiversity in forest management planning; (2) structural indicators such as tree species indicator, mean diameter (cm) and shrub biomass (Mg ha-1) are suitable for stand level biodiversity assessment. Pure blue gum stands on low-quality sites with shrub regenerating by seed had the lowest mean biodiversity, while mixed stands with a dominance of pine, on best-quality sites with shrub regeneration by resprouting had the highest mean biodiversity; (3) using umbrella species concept is suitable for the landscape level biodiversity assessments, and thus, here is estimated the red kite (Milvus milvus) nesting habitat suitability; the results suggested that the least favourable habitat would be in pure blue gum plantations, while mature cork oak forest would serve as the most appropriate long-term habitat.N/

Modelling of spatial dynamics and biodiversity conservation on Lure mountain (France)

International audienceOur study is part of a multi-disciplinary research project aimed at stimulating debate among researchers and local managers. The central question of this multi-disciplinary research project was to better understand and manage high biodiversity value open habitats threatened with shrub encroachment and landscape closure, a common problem throughout Europe. Here, we study shrub encroachment and its impact on biodiversity conservation in Mount Ventoux, a MAB Biosphere Reserve located at the southernmost tip of the French Alps. We show how using a multi-agent modelling approach provide a valuable framework to confront two potentially conflicting conservation efforts in this mountain Mediterranean landscape, that of the within-species diversity of a tree (Abies alba, the European silver fir) and that of an endangered species (Vipera ursinii ursinii, the Orsini viper). A companion modelling approach – approach which aims at transmitting and sharing knowledge, methods and tools that help understand and strengthen the collective decision making process of stakeholders sharing a common resource – was used in order to collectively represent the main activities underway on the mountain and to have a tool to address both open landscapes rehabilitation and restoration of forest environments. The co-construction of the model allowed us to build a shared representation of the territory under study and to develop and compare alternative management scenarios with local stakeholders, both to evaluate their impact on biodiversity and to provide information for forest and grazing management practic

A participatory modelling approach to developing a numerical sediment dynamics model

Despite the recognition of fluvial geomorphology as an important scientific input to the management of river catchments, limited knowledge exchange has occurred between scientific researchers and river management stakeholders. An example of this issue can be found within the limited uptake of numerical models of sediment dynamics by river management stakeholders. The uptake of these models is important as they have the potential to demonstrate how, at the catchment-scale, the impacts of management strategies of land-use change affect sediment dynamics and resulting channel quality. This thesis describes and evaluates a new transdisciplinary approach which involves river management stakeholders in an iterative and reflexive participatory modelling process. This approach aimed to create an environment for knowledge exchange and social learning between the stakeholders and the research team in the process of co-constructing a catchment-scale sediment dynamics model. This process involved four groups of UK river catchment stakeholders, who were involved in several stages of the participatory modelling process including: requirements analysis, model design, model development, model assessment, and an evaluation of the process. Stakeholders input into a number of aspects of the modelling process, such as: data requirements, user interface, modelled processes, model assumptions, model applications, and model outputs. The findings from the participatory modelling process provided valuable insights into the requirements of river management practitioners, and identified a number of gaps in knowledge for future research. The process evaluation critically assessed the participatory modelling process, and the solutions implemented to address the participatory issues identified in the literature. The findings revealed a number of methodological contributions including methods for ensuring participation is meaningful, and knowledge exchange and social learning occur. The usefulness and future of the developed model are also established through the model assessment. The conclusion reflects on these findings, identifies the implications for fluvial geomorphology and participatory modelling, and presents topics for future research

Modelo de interacção espacial: um instrumento para o planeamento e análise do território

As alterações do uso do solo processam-se de forma natural ou mediante alterações induzidas pelo Homem, tratando-se de um processo evolutivo do desenvolvimento dos ecossistemas e das civilizações. Neste trabalho, desenvolveram-se metodologias que resultaram numa aplicação informática (SIMLU), a qual implementa um modelo de interação espacial do uso do solo, com o propósito de analisar as relações entre o Homem, a economia e o ambiente, de forma a entender como determinados fatores edafoclimáticos, económicos, tecnológicos, demográficos e regulamentares, influenciam a ocupação e o uso do solo. O modelo permite simular a ocupação do solo ao longo do tempo e do espaço, face a cenários de mudanças climáticas, distribuindo emprego por sector de atividade e população pelas diferentes zonas consideradas, gerando repercussões na ocupação do território, na estrutura socioeconómica das populações e no valor da terra. A partir dos cenários de alterações climáticas (RCP4.5 e RCP8.5), previstos no Quinto relatório de avaliação do Painel Intergovernamental para as Alterações Climáticas (AR5- IPCC), aplicou-se o SIMLU a dois casos de estudo com características distintas: Tahaddart no Nordeste de Marrocos e na ilha Terceira no Arquipélago dos Açores. O modelo foi calibrado e validado para cada um dos dois casos de estudo, onde progressivamente foram introduzidas melhorias ao nível da capacidade de cálculo, análise e apresentação dos resultados, passando desde a primeira versão em formato Excel® (SIMLU V1.0), para a versão atual (SIMLU V2.0) numa aplicação autónoma e independente com interface gráfica para utilizadores. Para o caso de estudo de Tahaddart e áreas adjacentes, foram considerados para cada cenário RCP’s (horizonte temporal de 2099) dois tipos de sub-cenários: ocupação do uso do solo com base na estrutura produtiva e das aptidões de referência (2011) e ocupação do território através substituição do uso. Para cada cenário tratado, face à situação de referência, verificou-se uma diminuição da população que variou entre os 6818 e os 14244 habitantes (RCP4.5) e entre 48991 e os 43974 habitantes (RCP8.5). Para o caso de estudo aplicado á ilha Terceira, utilizou-se unicamente o cenário regionalizado RCP8.5 (horizonte temporal de 2099), não sendo admitido a substituição de uso relativamente à variação das normais climatológicas utilizadas (temperatura média anual e precipitação anual acumulada). Foi ainda considerado a redução dos postos de trabalho na Base Área das Lajes - BA4. Estimou-se os impactos na população e no valor da terra, resultante das alterações climáticas e da BA4. Dos resultados obtidos, verificase uma considerável redução da área de pastagem, que resulta na perda direta de cerca de 195 empregos ligados ao sector da pecuária a que se juntam 285 postos de trabalho suprimidos na BA4. O cenário simulado traduz-se numa diminuição de 2599 habitantes (cerca de 4% da população da Terceira em 2011) e um decréscimo global do valor da terra de cerca de 524 milhões de euros. O SIMLU apresenta-se assim como uma ferramenta de apoio à decisão, replicada em regiões e contextos diferentes, numa perspetiva de avaliar impactos na ocupação do uso do solo perante diferentes cenários de alterações climáticas; ABSTRACT: Spatial Interaction Model – A Tool for Land Analysis and Planning Land use changes are a result of natural or human induced changes, being an evolutionary process of ecosystems and civilizations. Methodologies were developed in this work, resulting in computer program (SIMLU) which implements a spatial interaction model of land use, with the aim of analyzing the relations between Man, the economy and the environment, and how edaphoclimatic (that affect land suitability), economic, technological, demographical factors and policies, can influence land use. The model allows us to simulate land use, through time and space, given climatic changes, distributing employment for activities and population for each considered zones, generate impacts in land use, socioeconomic structure of the populations and in the land value. Starting with the land use scenarios (RCP4.5 e RCP8.5), presented in the Fifth report of the Intergovernmental Panel for Climate Change (IPCC), SIMLU was applied in two case study areas with different characteristics: Tahaddart (Morocco) and Terceira island (Azores, Portugal). The model was calibrated and validated for each of the case study areas, improving on the calculation, analysis and outputs, starting from a Excel worksheet until arriving in the current form, an independent application with a user’s graphical interface. For each of the case studies, different outputs were presented allowing analysis of the model, as a decision support tool, which can be replicated for different contexts facing the evaluation of the impact of land use policies. Two types of sub-scenarios were considered in each RCP’s scenario, to Tahaddart basin: field occupation, based on productive structure and reference skills (2011) and occupation of the use replacement. In both scenarios, there was a population decrease raging 6818- 14244 habitants to RCP4.5 and 48991-43974 habitants to RCP8.5 scenario. For the case study applied to Terceira Island, only RCP8.5 was used for the temporal horizon to 2099, not admitting the use replacement relatively to the climatological norms used (average annual temperature and accumulated annual rainfall). The reduction of the working places in Air Base of Lajes- BA4, was also considered. The land values and the impact in population resulting from the climate changes and from the BA-4 was estimated. From the obtained results, a considerable decrease from the pasture area (resulting from the direct loss of the 195 jobs connected to the livestock) in which is added 285 jobs lost in BA-4. The simulated scenario indicates a diminution in the number of habitants, around 2599 (about 4% of the population in 2011) and a global decrease of the land value around 524 million euros. SIMLU presents as a support tool to decision, which can be replicated in different circumstances, concerning different scenarios in a way to evaluate the impacts of territory occupation regarding different climatic changes scenarios

Negotiating an uncertain future: a multi-study of narratives of Kenyan agricultural climate change adaptation

This research addresses the following question: ‘In the context of climate change, how do different actors narrate the uncertain, ambiguous and risky future of maize agriculture, and what are the implications?’ A multi-sited and institutional ethnography approach was adopted in order to look critically at how knowledge and narratives of future change in Kenyan maize agriculture are constructed by a variety of actors. The thesis describes: contested narratives of climate change and climate change impacts (through an analysis of the global climate impact modelling endeavour); contested narratives of change on smallholder farms (based on two case study sites in Kenya); contested narratives of pro-poor technological interventions (including the development of genetically modified drought tolerant maize); and contested narratives of technology regulation (with a focus on Kenyan biosafety policy). It is shown that narratives are contested in multiple sites and by a variety of actors and, although the resolution of these contestations often fall along familiar lines of power and elite capture, there are examples in which alternative perspectives find agency. This is the case not only in national policy-making arenas and the board-rooms of international development initiatives, but also in the fields and communities of smallholder farmers, the offices of national research centres, and the operations of civil society organisations. It is argued that, within these diverse settings, critical analysis of the constructed nature of knowledge is a necessary foundation on which to open up the negotiation of Kenya’s agricultural future to multiple alternatives