Identification des risques de perte de biodiversité face aux pressions anthropiques et au changement climatique à l’horizon 2100 : Application de la conservation dynamique au territoire des Alpes-Maritimes

The work aims at understanding how the land transformation and climatic change synergy could affect the Alpes-Maritimes biodiversity. This thesis contains four chapters. In the first chapter, the purpose is to provide the conceptual basis and the framework that support the scientific foundations of this thesis and the main conceptual definitions of the studied problematic. In the second chapter, the purpose is to study the artificialization process in the French Riviera area, its probable potential dispersion, the conditions and the factors involved in the phenomenon in order to give an intuitively understanding of the landscape transformation and their principal trend. The landscape transformation of the last 40 years has been studied with the aim of identifying the spatial transition rules that have been introduced in the cellular automata model. We present a synthesis of landscape transformation in the French Riviera up to 2050 and 2100. The resulting scenarios provide information about future urban expansion according to historic behavior and the evolutionary patterns. The results of this part show that urban surfaces could double by 2050 and triplicated by 2100 compared with 2011. In the third chapter we assess the biodiversity loss according to land use dynamic and climate change. We first defined the ecosystem diversity by the landscape units. The landscape units are composed by the different ecological factors that have had an influence on ecosystems repartition like geomorphology, soil, climate, and vegetation. Then, we studied how landscape transformation could affect the biodiversity in the future by the spatial superposition of the first and second chapter results. Next, we realized a bioclimatic calibration for the landscape units with the aim of understanding the limits of ecological tolerance to the climatic conditions and the different ecological conditions like geomorphology, soil, and aspect. The bioclimatic calibration of the landscape units has allowed the definition of climatic change impact on ecosystem biodiversity for 2050 and 2100.The synergy between climatic change impact and landscape transformation shows that almost 30% (68 ecosystem expressions) of Alpes-Maritimes biodiversity could be affected at the end of the XXIst century, and at least five ecosystems expressions could disappear for 2100 due to both forces or some of these driving forces.In the fourth chapter we propose a method that allows the integration of climatic change impacts and landscape transformation on conservation process and politic assessment. Moreover, this chapter proposes the possibility to integrate both phenomena into the ecological networks structuration, especially into “Trame verte et bleue” in France.L'objectif est de comprendre comment la synergie entre la transformation du territoire et le changement climatique pourra affecter la biodiversité des Alpes-Maritimes à l'horizon 2100. Cette thèse comprend quatre chapitres. Dans le premier chapitre sont présentées les notions, les bases théoriques et conceptuelles ainsi que la problématique générale de recherche. Le deuxième chapitre est consacré à l'étude des processus d'artificialisation et de transformation territoriale. Dans cette partie sont évalués le processus de dispersion ainsi que les facteurs qui interviennent dans les phénomènes d'artificialisation du territoire et les tendances futures de changement sur les Alpes-Maritimes. Les règles de transition spatiale ont été extraites à partir de l'étude de la transformation territoriale des 40 dernières années pour comprendre les trajectoires de changement, mais aussi dans le but d'avoir une base de connaissances solide permettant de faire la simulation par automate cellulaire. A partir de ces connaissances et de l'interprétation des règles de transition sont élaborés les scénarios de transformation future du paysage aux horizons 2050 et 2100. Les résultats montrent la possible expansion de l'artificialisation selon le comportement et les tendances historiques observés sur le territoire. Les résultats de ce chapitre montrent que les surfaces artificielles pourraient doubler pour 2050, et tripler pour 2100 par rapport à leur occupation actuelle. Le troisième chapitre concerne l'évaluation de la perte de biodiversité selon les pressions anthropiques et climatiques. La première partie du chapitre trois est dédiée à la définition de la diversité écosystémique à partir des unités du paysage. Pour cette définition ont été considérés les différents facteurs écologiques qui ont une influence sur la répartition des écosystèmes tels que la géomorphologie, le sol, le climat et la végétation. Avec les informations obtenues dans la partie précédente, est étudié l'impact potentiel de la transformation territoriale sur la biodiversité. La deuxième partie de ce chapitre consiste en la réalisation d'un étalonnage bioclimatique des unités du paysage, afin de comprendre les limites écologiques de tolérance des expressions écosystémique aux conditions climatiques et géomorphologiques. Au total sont définies 236 unités du paysage sur lesquelles sont estimés les impacts synergiques de la transformation territoriale et du changement climatique afin d'évaluer les risques de perte de biodiversité vers la fin du siècle. Les résultats montrent que 68 unités du paysage (soit presque 30% de la diversité́ des Alpes-Maritimes) seront affectées par ces deux phénomènes d'ici la fin du XXIème siècle et 5 d'entre elles devraient disparaître, que ce soit en raison du changement climatique ou de la dynamique de l'artificialisation du sol. Le dernier chapitre propose une méthode permettant l'intégration des impacts du changement climatique et des impacts de la transformation territoriale dans les processus de conception et définition de politiques de conservation dynamique de la biodiversité. De plus, ce chapitre propose la possibilité d'intégrer les deux phénomènes dans la conception de réseaux écologiques de conservation, notamment dans le cadre de la Trame verte et bleue

Identification of Biodiversity loss Risk at the end of XXIst Century due to anthropic pressures and climatic change : French Riviera territory application of dynamical conservation

L'objectif est de comprendre comment la synergie entre la transformation du territoire et le changement climatique pourra affecter la biodiversité des Alpes-Maritimes à l'horizon 2100. Cette thèse comprend quatre chapitres. Dans le premier chapitre sont présentées les notions, les bases théoriques et conceptuelles ainsi que la problématique générale de recherche. Le deuxième chapitre est consacré à l'étude des processus d'artificialisation et de transformation territoriale. Dans cette partie sont évalués le processus de dispersion ainsi que les facteurs qui interviennent dans les phénomènes d'artificialisation du territoire et les tendances futures de changement sur les Alpes-Maritimes. Les règles de transition spatiale ont été extraites à partir de l'étude de la transformation territoriale des 40 dernières années pour comprendre les trajectoires de changement, mais aussi dans le but d'avoir une base de connaissances solide permettant de faire la simulation par automate cellulaire. A partir de ces connaissances et de l'interprétation des règles de transition sont élaborés les scénarios de transformation future du paysage aux horizons 2050 et 2100. Les résultats montrent la possible expansion de l'artificialisation selon le comportement et les tendances historiques observés sur le territoire. Les résultats de ce chapitre montrent que les surfaces artificielles pourraient doubler pour 2050, et tripler pour 2100 par rapport à leur occupation actuelle. Le troisième chapitre concerne l'évaluation de la perte de biodiversité selon les pressions anthropiques et climatiques. La première partie du chapitre trois est dédiée à la définition de la diversité écosystémique à partir des unités du paysage. Pour cette définition ont été considérés les différents facteurs écologiques qui ont une influence sur la répartition des écosystèmes tels que la géomorphologie, le sol, le climat et la végétation. Avec les informations obtenues dans la partie précédente, est étudié l'impact potentiel de la transformation territoriale sur la biodiversité. La deuxième partie de ce chapitre consiste en la réalisation d'un étalonnage bioclimatique des unités du paysage, afin de comprendre les limites écologiques de tolérance des expressions écosystémique aux conditions climatiques et géomorphologiques. Au total sont définies 236 unités du paysage sur lesquelles sont estimés les impacts synergiques de la transformation territoriale et du changement climatique afin d'évaluer les risques de perte de biodiversité vers la fin du siècle. Les résultats montrent que 68 unités du paysage (soit presque 30% de la diversité́ des Alpes-Maritimes) seront affectées par ces deux phénomènes d'ici la fin du XXIème siècle et 5 d'entre elles devraient disparaître, que ce soit en raison du changement climatique ou de la dynamique de l'artificialisation du sol. Le dernier chapitre propose une méthode permettant l'intégration des impacts du changement climatique et des impacts de la transformation territoriale dans les processus de conception et définition de politiques de conservation dynamique de la biodiversité. De plus, ce chapitre propose la possibilité d'intégrer les deux phénomènes dans la conception de réseaux écologiques de conservation, notamment dans le cadre de la Trame verte et bleue.The work aims at understanding how the land transformation and climatic change synergy could affect the Alpes-Maritimes biodiversity. This thesis contains four chapters. In the first chapter, the purpose is to provide the conceptual basis and the framework that support the scientific foundations of this thesis and the main conceptual definitions of the studied problematic. In the second chapter, the purpose is to study the artificialization process in the French Riviera area, its probable potential dispersion, the conditions and the factors involved in the phenomenon in order to give an intuitively understanding of the landscape transformation and their principal trend. The landscape transformation of the last 40 years has been studied with the aim of identifying the spatial transition rules that have been introduced in the cellular automata model. We present a synthesis of landscape transformation in the French Riviera up to 2050 and 2100. The resulting scenarios provide information about future urban expansion according to historic behavior and the evolutionary patterns. The results of this part show that urban surfaces could double by 2050 and triplicated by 2100 compared with 2011. In the third chapter we assess the biodiversity loss according to land use dynamic and climate change. We first defined the ecosystem diversity by the landscape units. The landscape units are composed by the different ecological factors that have had an influence on ecosystems repartition like geomorphology, soil, climate, and vegetation. Then, we studied how landscape transformation could affect the biodiversity in the future by the spatial superposition of the first and second chapter results. Next, we realized a bioclimatic calibration for the landscape units with the aim of understanding the limits of ecological tolerance to the climatic conditions and the different ecological conditions like geomorphology, soil, and aspect. The bioclimatic calibration of the landscape units has allowed the definition of climatic change impact on ecosystem biodiversity for 2050 and 2100.The synergy between climatic change impact and landscape transformation shows that almost 30% (68 ecosystem expressions) of Alpes-Maritimes biodiversity could be affected at the end of the XXIst century, and at least five ecosystems expressions could disappear for 2100 due to both forces or some of these driving forces.In the fourth chapter we propose a method that allows the integration of climatic change impacts and landscape transformation on conservation process and politic assessment. Moreover, this chapter proposes the possibility to integrate both phenomena into the ecological networks structuration, especially into “Trame verte et bleue” in France

Expected Global Warming Impacts on the Spatial Distribution and Productivity for 2050 of Five Species of Trees Used in the Wood Energy Supply Chain in France

International audienc

Potential effects of global warming on the spatial distribution and productivity of five tree species used in the wood energy supply chain in France for 2050

International audienc

Expected Global Warming Impacts on the Spatial Distribution and Productivity for 2050 of Five Species of Trees Used in the Wood Energy Supply Chain in France

The development of collective and industrial energy systems, based on wood biomass, knows a significant increase since the end of the 90’s in France, with more than 6000 power plants and heating plants developed currently. Because these systems are built for a minimal duration of 30 years, it is relevant to assess the availability of wood resources according to the potential impacts of global warming on five tree species mainly used in such a supply chain. The assessment of the potential spatial distribution of the suitable areas of these trees in 2050, by using the IPCC (Intergovernmental Panel on Climate Change) RCP6.0 scenario (Representative Concentration Pathway), shows an average decrease of 22% of the plots in comparison with the current situation. The results also point out that mountain areas would maintain a high probability of the development of four tree species. The assessment of the Net Primary Productivity (NPP) underlines a potential decrease for 93% of the plots in 2050, and an increase of this parameter in mountain areas. According to these assumptions, the proposed ecosystem based methodology can be considered as a prospective approach to support stakeholders’ decisions for the development of the wood energy supply chain

Urban dynamics simulation and climatic change scenarios for 2050 in order to identify areas of biodiversity's conservation in the French's Maritime Alps

International audienceThe growth of the population's centers and cities has been considered as the first element of change in the terrestrial planetary ecosystems. The change of ecosystems functioning generated by landscape fragmentation is currently the principal risk for the biodiversity conservation. According to the IPCC scenarios, it's possible that climatic change will have a harder effect in fragmented areas in comparison with less or not fragmented areas. The purpose of this study is to provide a Spatial Decision Support System (SDSS) in order to evaluate the consequences of urbanization and climatic change effects in France (French Riviera) on biodiversity. The process of evaluation consists of identifying the possible dynamics of urbanization using cellular automata model for simulation (SpaCelle) and multi agents systems (NetLogo) according to spatial process on the considered territory. This evaluation is performed using a set of spatial data to understand historic patron or growth and transition spatial rules in order to project the future scenarios of landscape changes. The second step is the characterization of the relationship between climate and ecosystems according to the current climate, which is the first element to calibrate the climatic change model. This process is performed using the botanical database "Sophy". With the identification of the climatic changes using the reference scenarios provided by the IPCC, a projection of the potential changes in the ecosystems 2050 is realized. Finally, with the information provided by the scenario of possible urbanization and of the potential evolution of ecosystems, the SDSS will give a vision of the sensitive areas and territorial conflicts. The results of this research will show a possibility to provide a systematic method to make decisions with a better certainty and coherence to establish areas of biodiversity conservation

Effets probables du réchauffement climatique sur le risque d’incendie de forêt en Corse et application du dispositif juridique de prévention

Corsica is a territory which is particularly exposed to forest fire risks. The existing legal framework for preventing this risk presents many measures and steps to ensure the safety of the people and the goods. However, the level of forest fire risk may evolve due to climate change, particularly because of the evolution and the expansion of the ecosystems associated with this risk. In this context, we show that the inclusion of such projections need to focus on the complementarity between spatial modeling results showing the potential increase of surfaces exposed to the fire risk, with the implementation of legal risk prevention measures. We also wonder about the needs of change of these measures to a systemic view of risk prevention in the context of anticipated change over a long period

Evolution of the legal prevention measures concerning forest fire risk in a context of climate change

International audienceIn a context of climate change that may increase the extreme events and so the forest fires, the question is to know whether the legal framework is relevant or it should keep on evolving to manage the forest fire prevention risk. Many reports concerning the climate change and also the forest fire risk in France pointed the necessary adaptation of the public policies and the lack of the legal prevention measures. So, the question is what the main legal measures are to be developed or to be implemented in the territories actually exposed to forest fire which could be more exposed to this risk and the territories which are not exposed for that moment but which could be exposed in the future

Describing and predicting of the vegetation development of Corsica due to expected climate change and its impact on forest fire risk evolution

International audienceAmong the consequences pointed out by the Intergovernmental Panel on Climate Change (IPCC), it is assumed that xeric and thermophilic ecosystems, which are mostly involved in forest fires, could colonize areas currently less or not exposed to forest fire risk. The aim of our study is to assess the spatial distribution of xeric and thermophilic botanical taxa in Corsica for the end of the 21st Century, according to the climatic scenario named RCP 6 which is considered as one of the most probable reference scenario. The results of our study show a probable increase of forest fire risk due to the colonization of xeric and thermophilic ecosystems in more areas than we can observe today