No description available.

The study explores the possibility of conflicts between conservation of wetlands and semi-natural grasslands in the county of Stockholm. Both habitats are important to protect from a biodiversity perspective. The species rich semi-natural grasslands have been created by agricultural practices like grazing and mowing. At the same time, wetlands have diminished due to earlier drainage in order to increase the area of arable land. Both habitats are incorporated in the Swedish Environmental Objectives and are parts of the EU’s Agri-Environmental Schemes (AES), where farmers get financial support to maintain or restore valuable habitats. Wetland conservation/restoration often requires raised water tables, but also maintenance with cattle grazing in certain areas. On the other hand, raised water tables can act as hinder for grazing animals and lead to conflict situations. Using a mixed method approach, this study scrutinized if the use of different management tools can result in conflicts between actors and objectives. The study is based on a literature review, interviews and the use of Geographical Information Systems (GIS). Institutionalism and the Institutional Analysis and Development framework are used to analyze and evaluate the situation in the county of Stockholm. The quantitative results reveal that 12,8 % of all semi-natural grasslands of high biological value intersects with wetlands. However, these areas are maintained with environmental support to a larger extent than semi-natural grasslands outside wetlands. This indicates there is no conflict between wetland and semi-natural grassland conservation, a perception shared by authorities. From farmers’ perspective the situation is described differently, rule compliance for environmental support is hard to obtain specifically in wet areas. Increased dialogue between authorities and farmers rather than harsh inspections would be preferable as the county of Stockholm needs more farmers and grazing cattle to maintain biologically important habitats. Grazing in wetlands is needed from a biodiversity perspective but can at the same time disturb the wetlands functioning of nutrient reduction. There is a risk of authorities prioritizing water quality in front of biodiversity in conflicting situations. Water, as a common-pool recourse, is surrounded by stricter regulation and also easier to monitor.

La politique agro-environnementale de l’Union Européenne s’appuie fortement sur des incitations financières, les Contrats Agro-Environnementaux (CAE), pour stimuler l’adoption par les agriculteurs de pratiques respectueuses de l’environnement. Selon l’hypothèse de rationalité économique, les agriculteurs adoptent ces contrats si les paiements couvrent leurs coûts d’opportunité. Toutefois, l’Économie comportementale considère que des facteurs psychologiques pourraient intervenir dans cette décision. Le premier objectif de cette thèse est de déterminer le rôle des facteurs comportementaux dans l’adoption des CAE. Dans le chapitre 1, nous utilisons un modèle de psychologie sociale, la Théorie du Comportement Planifié, pour mesurer le poids de ces facteurs dans la décision d’adopter un CAE pour la réduction de l’utilisation de pesticides. L’enquête révèle que les agriculteurs sont à la fois influencés par des motivations économiques classiques et par les normes (sociales et personnelles). Dans le chapitre 2, nous étudions plus en détails le rôle des normes. A travers un modèle théorique, nous mettons en évidence que ces normes peuvent faciliter ou faire obstacle à l’adoption de CAE. Une enquête web nous permet de confirmer l’importance des normes sociales injonctives et des normes personnelles. Dans la deuxième partie de la thèse, nous analysons les performances de dispositifs innovants et comment ces performances sont influencées par les facteurs comportementaux. Dans le chapitre 3, pour traiter le problème des seuils environnementaux, nous testons avec une expérimentation économique un contrat dont le paiement est conditionné à une participation collective des agriculteurs. Ce contrat se révèle plus efficace et efficient que les CAE classiques. Les deux derniers chapitres traitent d’une nouvelle application des CAE à la compensation écologique. A partir d’une enquête, nous identifions dans le chapitre 4 les facteurs qui influencent la participation à ce type de contrats ainsi que des problèmes d’efficacité et d’efficience. Dans le chapitre 5, nous montrons à partir d’une expérience de choix, que les agriculteurs, notamment les plus sensibles à l’environnement, sont sensibles à la manière dont est formulée l’objectif d’un CAE : ils préfèrent des contrats dont l’objectif est la préservation de la biodiversité, plutôt que la compensation de pertes de biodiversité. Nous concluons en insistant sur la complémentarité entre les instruments traditionnels et comportementaux dans la politique environnementale. / The agri-environmental policy of the European Union strongly relies on financial incentives provided through Agri-envrionmental Schemes (AES) to stimulate farmers’ adoption of pro-environmental practices. A rational economic assumption is that farmers enroll if they are paid enough to cover their opportunity costs. However, behavioral economics consider that psychologic factors may be involved in this decision. The first aim of this thesis is to determine the role of behavioral factors in AES adoption. Chapter 1 uses a social-psychology model, the Theory of Planned Behavior, to measure the weight of behavioral factors in farmers’ decision to enroll in a pesticide-reduction AES. The survey reveals that farmers are both driven by traditional economic motivations and norms (social and personal). Chapter 2 studies in more details the role of norms. A theoretical model reveals that social norms may either hamper or facilitate the participation in AES and a web-survey, confirms the importance of social injunctive norms and personal norms. In the second part of the thesis, we analyze the performance of innovative designs and how it may be affected by behavioral factors. In chapter 3, to address cases of environmental threshold, we test with an economic experiment a contract in which payment is conditioned to collective farmers’ participation. This contract appears to be more effective and efficient than traditional AES. The two last chapters analyze a new application of AES: biodiversity offsets. Based on a survey, chapter 4 highlights factors that influence the participation in such contracts as well as issues of effectiveness and efficiency. In chapter 5, we show with a choice experiment that farmers, especially the most environmentally sensitive, are influenced by the contracts’ goal framing: they prefer contracts that aim at biodiversity conservation rather than at the compensation of biodiversity losses. We conclude by insisting on the complementarity between traditional and behavioral environmental policy instruments.

La crescente attenzione riguardo l’interconnessione tra agricoltura e aspetti ambientali così come la crescita di volatilità dei prezzi dei prodotti agricoli ha posto una nuova enfasi sull’introduzione di misure ambientali nella politiche agricole e sulla ricerca di nuovi strumenti di stabilizzazione del reddito degli agricoltori. La ricerca di questa tesi di dottorato si inserisce in questo contesto e analizza i contratti agro-ambientali, misure della Politica Agricola Comunitaria (PAC) in Unione Europea (UE), sotto una duplice prospettiva. Il primo lavoro di ricerca consiste in un’analisi degli effetti dell’adesione a tali contratti sulle scelte produttive e sulle perfomance economiche degli agricoltori in cinque Paesi dell’UE. I risultati indicano un’eterogeneità di questi effetti: in alcuni Paesi i contratti agro-ambientali sembrano essere più efficaci nel promuovere pratiche agricole sostenibili, così come in alcuni Paesi il pagamento compensativo agro-ambientale sembra non essere sufficiente a compensare la perdita di reddito dei partecipanti. Questo studio è stato condotto combinando il Propensity Score Matching con lo stimatore Difference-in-Differences. Il secondo lavoro di ricerca sviluppa una nuova proposta metodologica che incorpora il rischio in un framework di Programmazione Matematica Positiva (PMP). Il modello elaborato presenta caratteri innovativi rispetto alla letteratura sull’argomento e permette di stimare simultaneamente i prezzi ombra delle risorse, la funzione di costo non lineare dell’azienda agricola e un coefficiente di avversione al rischio specifico per ciascuna azienda. Il modello è stato applicato a tre campioni di aziende e i risultati delle stime testano la calibrazione del modello e indicano valori del coefficiente di avversione al rischio coerenti con la letteratura. Infine il modello è stato impiegato nella simulazione di diversi scenari al fine di verificare il ruolo potenziale di un contratto agro-ambientale come strumento di gestione del rischio a diversi livelli di volatilità dei prezzi agricoli. / The increasing attention to the relationship between agriculture and the environment and the rise in price volatility on agricultural markets has led to a new emphasis on agri-environmental policies as well as to a search for new risk management strategies for the farmer. The research objective of this PhD thesis is in line with this challenging context, since it provides an analysis of the EU agri-environmental schemes (AESs) from two viewpoints. First, an ex-post analysis aims at investigating the AESs for their traditional role as measures which encourage sustainable farming while compensating the farmer for the income foregone in five EU Member States. The effects of AESs participation on farmer’s production plans and economic performances differs widely across Member States and in some of them the environmental payment is not enough to compensate the income foregone of participants. This study has been performed by applying a semi-parametric technique which combines a Difference-in-Differences estimator with a Propensity Score Matching estimator. The second piece of research develops a new methodological proposal to incorporate risk into a farm level Positive Mathematical Programming (PMP) model. The model presents some innovations with respect to the previous literature and estimates simultaneously the resource shadow prices, the farm non-linear cost function and a farm-specific coefficient of absolute risk aversion. The proposed model has been applied to three farm samples and the estimation results confirm the calibration ability of the model and show values for risk aversion coefficients consistent with the literature. Finally different scenarios have been simulated to test the potential role of an AES as risk management tool under different scenarios of crop price volatility.

No description available.

L'effondrement des populations d'abeilles domestiques, observé à l'échelle mondiale depuis une vingtaine d'années, est particulièrement alarmant, provoquant le déclin de la filière apicole mais également celui d'un pollinisateur essentiel en milieu agricole. La conservation de l'abeille domestique et de l'apiculture en paysage agricole est donc actuellement un enjeu majeur pour de nombreux acteurs. L'intensification de l'agriculture, insufflée par la politique agricole européenne, est désignée comme une cause majeure dans le déclin de la biodiversité, dont les abeilles sauvages. De nombreuses études ont révélé que le manque de ressources florales est une cause majeure de ce déclin généralisé, mais de façon surprenante, cette cause n'est que très peu investiguée à l'heure actuelle pour l'abeille domestique. Plus généralement, l'écologie de l'abeille domestique en paysage agricole est mal connue. A l'interface entre écologie comportementale, évolutive et paysagère, l'objectif général de cette thèse est d'étudier l'influence conjuguée de l'intensification de l'agriculture et de la dynamique spatio-temporelle des ressources florales en paysage agricole sur (i) leur utilisation et (ii) l'histoire de vie des abeilles. L'originalité de cette étude provient de l'envergure spatiale et temporelle des données empiriques collectées à l'aide de vastes dispositifs de suivis tant au niveau individuel qu'au niveau des colonies. Les résultats obtenus confirment l'influence négative de l'intensification de l'agriculture sur l'écologie de l'abeille domestique. En effet, la dynamique des ressources dominées par trois cultures majeures que sont le colza, le tournesol et le maïs, provoque l'apparition d'une déplétion d'approvisionnement en pollen et nectar. Des ressources aujourd'hui marginalement présentes en paysage agricole intensif telles que les zones boisées et les adventices jouent un rôle prépondérant dans le régime alimentaire des abeilles, pouvant contrer l'intensité de cette déplétion d'approvisionnement. Par des mécanismes a priori adaptatifs, les colonies et les individus adaptent leurs comportements et histoire de vie en réponse à la déplétion d'approvisionnement. Cependant, ces mécanismes de compromis d'allocation des ressources ont un coût important et aboutissent à un affaiblissement des colonies, qui se traduit par la mortalité hivernale des colonies d'abeilles domestiques. Cette étude révèle empiriquement l'importance de la dynamique des ressources dans les causes du déclin de l'abeille domestique, et évoque la présence d'une disette alimentaire en céréaliculture intensive. Ces résultats sont discutés dans l'optique de concevoir des mesures de conservation de l'abeille domestique, de l'apiculture et du service de pollinisation en paysage agricole intensif, afin de limiter les stress environnementaux pour les abeilles tels que le manque de ressources florales et l'exposition aux pesticides. / The collapse of honey bee populations, described around the world for twenty years, is particularly alarming because it causes the decline of beekeeping and of an essential pollinator in agricultural habitats. The conservation of honey bees and beekeeping in agricultural landscape is currently a major challenge for many operators. The agricultural intensification, instilled by the (European) Common Agricultural Policy, is considered as a major cause in the decline of biodiversity, including wild bees. Many studies have shown that lack of floral resources is a major cause of this widespread, but surprisingly, this cause of decline is very few investigated actually to honey bees. More generally, the honey bee ecology in agricultural landscapes is poorly understood. At the interface between behavioral, evolutionary and landscape ecology, the overall objective of this PhD thesis was to study the combined influences of agricultural intensification and the spatio-temporal dynamics of floral resources on (i) the use of this resource and (ii) the life history of honey bees. The originality of this study comes from its large spatial and temporal scale as well as its joint approach at individual and colony levels. The results confirm a negative impact of agricultural intensification on the honey bee. Indeed, three major crops i.e. rapeseed, sunflower and maize have created a temporal resource dynamic which causes a strong food supply depletion in pollen and nectar. Some resources more marginally represented in intensive agricultural landscapes such as wood and weeds play an important role in the honey bee diet, being able to restrict the intensity of food supply depletion. By adaptive mechanisms, colonies and individuals adapt their behavior and life history in response to the food supply depletion. However, these trade-off mechanisms in resource allocation have a significant cost and generate a weakening of colonies that increases overwintering mortality of honey bee colonies. This study shows empirically the importance of the resource dynamic in the causes of honey bee decline, and highlights the presence of a food-shortage period in cereal farming systems. These results are discussed so as to build conservation measures on the honey bee, beekeeping and pollination service in intensive agricultural landscapes, in order to limit environmental stress for honey bees such as lack of floral resources and pesticide exposure.