The management of natural resources located on private lands often involves a perceived conflict between the mix of private and public benefit outputs they produce. Governments have tended to respond through legislation to restrict and redirect private decisions about resource management. However, the legislative response faces a lack of information about the costs and benefits of alternative management and policy instruments. A pertinent example of this debate is the management of wetlands on private lands. The goal in this thesis is to advance the design of policy relating to the production of environmental outputs on private lands. This goal is achieved by first estimating the welfare impacts of alternative private land management strategies on the wider community. These estimates are used as inputs into the development of alternative policy instruments that are then evaluated in terms of their potential cost-effectiveness in influencing private management. Two case studies of wetland management on private land in Australia are presented ??? the Upper South East Region of South Australia, and, the Murrumbidgee River Floodplain in New South Wales. The conceptual approach described in the first part of the thesis includes a description of the resource management problem and the strengths and weaknesses of the alternative decision frameworks widely employed in Australia. Identification of the cause and nature of transaction costs in the management process is the focus in this discussion. The welfare impacts of alternative wetland management strategies are investigated through the construction of a bio-economic model for each of the case study areas. The approach integrates biophysical analysis of changing wetland management with the value society places on wetlands. Outputs from this process are used in the development of a range of policy instruments directed towards influencing wetland management. The impact of poorly quantified and uncertain transaction costs on the potential cost-effectiveness of these options is evaluated using threshold policy analysis. The empirical results show that the perception of a conflict between the private and public values generated by resource management is accurate. For example, scenarios changing wetland management in the Upper South East of South Australia on the Murrumbidgee River floodplain in New South Wales were shown to generate net benefits of $5.2m and $5.1m respectively. Hence, changing wetland management could generate increased community welfare. The potential for these findings to be translated into wetland policy is less conclusive. Policies directed towards wetland management (in part or in whole) incur a range of transaction costs and deliver differential wetland protection benefits. Ten ???best bet??? policies are identified, but more information is required to determine conclusively whether a net benefit results to the wider community when transaction costs are included.

The management of natural resources located on private lands often involves a perceived conflict between the mix of private and public benefit outputs they produce. Governments have tended to respond through legislation to restrict and redirect private decisions about resource management. However, the legislative response faces a lack of information about the costs and benefits of alternative management and policy instruments. A pertinent example of this debate is the management of wetlands on private lands. The goal in this thesis is to advance the design of policy relating to the production of environmental outputs on private lands. This goal is achieved by first estimating the welfare impacts of alternative private land management strategies on the wider community. These estimates are used as inputs into the development of alternative policy instruments that are then evaluated in terms of their potential cost-effectiveness in influencing private management. Two case studies of wetland management on private land in Australia are presented ??? the Upper South East Region of South Australia, and, the Murrumbidgee River Floodplain in New South Wales. The conceptual approach described in the first part of the thesis includes a description of the resource management problem and the strengths and weaknesses of the alternative decision frameworks widely employed in Australia. Identification of the cause and nature of transaction costs in the management process is the focus in this discussion. The welfare impacts of alternative wetland management strategies are investigated through the construction of a bio-economic model for each of the case study areas. The approach integrates biophysical analysis of changing wetland management with the value society places on wetlands. Outputs from this process are used in the development of a range of policy instruments directed towards influencing wetland management. The impact of poorly quantified and uncertain transaction costs on the potential cost-effectiveness of these options is evaluated using threshold policy analysis. The empirical results show that the perception of a conflict between the private and public values generated by resource management is accurate. For example, scenarios changing wetland management in the Upper South East of South Australia on the Murrumbidgee River floodplain in New South Wales were shown to generate net benefits of $5.2m and $5.1m respectively. Hence, changing wetland management could generate increased community welfare. The potential for these findings to be translated into wetland policy is less conclusive. Policies directed towards wetland management (in part or in whole) incur a range of transaction costs and deliver differential wetland protection benefits. Ten ???best bet??? policies are identified, but more information is required to determine conclusively whether a net benefit results to the wider community when transaction costs are included.

The management of natural resources located on private lands often involves a perceived conflict between the mix of private and public benefit outputs they produce. Governments have tended to respond through legislation to restrict and redirect private decisions about resource management. However, the legislative response faces a lack of information about the costs and benefits of alternative management and policy instruments. A pertinent example of this debate is the management of wetlands on private lands. The goal in this thesis is to advance the design of policy relating to the production of environmental outputs on private lands. This goal is achieved by first estimating the welfare impacts of alternative private land management strategies on the wider community. These estimates are used as inputs into the development of alternative policy instruments that are then evaluated in terms of their potential cost-effectiveness in influencing private management. Two case studies of wetland management on private land in Australia are presented ??? the Upper South East Region of South Australia, and, the Murrumbidgee River Floodplain in New South Wales. The conceptual approach described in the first part of the thesis includes a description of the resource management problem and the strengths and weaknesses of the alternative decision frameworks widely employed in Australia. Identification of the cause and nature of transaction costs in the management process is the focus in this discussion. The welfare impacts of alternative wetland management strategies are investigated through the construction of a bio-economic model for each of the case study areas. The approach integrates biophysical analysis of changing wetland management with the value society places on wetlands. Outputs from this process are used in the development of a range of policy instruments directed towards influencing wetland management. The impact of poorly quantified and uncertain transaction costs on the potential cost-effectiveness of these options is evaluated using threshold policy analysis. The empirical results show that the perception of a conflict between the private and public values generated by resource management is accurate. For example, scenarios changing wetland management in the Upper South East of South Australia on the Murrumbidgee River floodplain in New South Wales were shown to generate net benefits of $5.2m and $5.1m respectively. Hence, changing wetland management could generate increased community welfare. The potential for these findings to be translated into wetland policy is less conclusive. Policies directed towards wetland management (in part or in whole) incur a range of transaction costs and deliver differential wetland protection benefits. Ten ???best bet??? policies are identified, but more information is required to determine conclusively whether a net benefit results to the wider community when transaction costs are included.

The management of natural resources located on private lands often involves a perceived conflict between the mix of private and public benefit outputs they produce. Governments have tended to respond through legislation to restrict and redirect private decisions about resource management. However, the legislative response faces a lack of information about the costs and benefits of alternative management and policy instruments. A pertinent example of this debate is the management of wetlands on private lands. The goal in this thesis is to advance the design of policy relating to the production of environmental outputs on private lands. This goal is achieved by first estimating the welfare impacts of alternative private land management strategies on the wider community. These estimates are used as inputs into the development of alternative policy instruments that are then evaluated in terms of their potential cost-effectiveness in influencing private management. Two case studies of wetland management on private land in Australia are presented ??? the Upper South East Region of South Australia, and, the Murrumbidgee River Floodplain in New South Wales. The conceptual approach described in the first part of the thesis includes a description of the resource management problem and the strengths and weaknesses of the alternative decision frameworks widely employed in Australia. Identification of the cause and nature of transaction costs in the management process is the focus in this discussion. The welfare impacts of alternative wetland management strategies are investigated through the construction of a bio-economic model for each of the case study areas. The approach integrates biophysical analysis of changing wetland management with the value society places on wetlands. Outputs from this process are used in the development of a range of policy instruments directed towards influencing wetland management. The impact of poorly quantified and uncertain transaction costs on the potential cost-effectiveness of these options is evaluated using threshold policy analysis. The empirical results show that the perception of a conflict between the private and public values generated by resource management is accurate. For example, scenarios changing wetland management in the Upper South East of South Australia on the Murrumbidgee River floodplain in New South Wales were shown to generate net benefits of $5.2m and $5.1m respectively. Hence, changing wetland management could generate increased community welfare. The potential for these findings to be translated into wetland policy is less conclusive. Policies directed towards wetland management (in part or in whole) incur a range of transaction costs and deliver differential wetland protection benefits. Ten ???best bet??? policies are identified, but more information is required to determine conclusively whether a net benefit results to the wider community when transaction costs are included.

Alternative grazing systems and pasture types for wool production in the south west of Western Australia were analysed using bio-economic modelling techniques in order to determine their relative productivity and profitability. After reviewing the experimental and modelling literature on perennial pastures and grazing systems, seven case studies of farmers were conducted in order to investigate the practical application of innovative grazing systems and use of perennial pastures. Together these case studies provided information for identifying relevant variables and for calibrating the modelling work which followed. The core of the work lies in a bio-economic model for investigating the comparative value of the three grazing systems and two pasture families mentioned above. A baseline scenario using currently available and reliable scientific data provides baseline results, after which a number of sensitivity analyses provide further insights using variations of four key parameters: persistence, heterogeneity, water soluble carbohydrates, and increased losses. Results show that perennial pastures are in the studied region more profitable than annual pastures. Under current baseline conditions, continuous grazing with perennial pastures is the most profitable enterprise, but this superiority is not robust under parameter variations defined by other scenarios. The more robust solution in terms of enterprise profitability is cell grazing with perennial pastures. The results indicate that intensive grazing systems such as cell grazing have the potential to substantially increase the profitability of grazing operations on perennial pasture. This result is an encouraging one in light of its implications for water uptake and salinity control. It means that economics and land care can go hand in hand, rather than be competitive. It is to be noted that it is the choice of the grazing system in combination with the pasture species, rather then the pasture species itself, that allows for such complementarity between economics and sustainable land use. This research shows that if farmers adopt practices such as cell grazing they may be able to increase the area that they can profitably plant to perennial pasture thus reducing the impacts of dryland salinity. This finding is consistent with the findings of the case studies where the farmers perceived that, provided grazing was planned, increasing the intensity of their grazing management and the perenniallity of their pastures would result in an increase in the profitability of their grazing operation. As a result this research helps to bridge a gap which has existed in this area of research, between the results of scientific research and those reported in practice.

L’objectif général de la thèse est de modéliser les principaux processus biologiques et économiques régissant des pêcheries multi-espèces et multi-flottilles afin de proposer des stratégies viables pour la gestion durable de ces pêcheries mixtes, dans un contexte stochastique et multiobjectif. Plus spécifiquement, cette thèse utilise des analyses de co-viabilité stochastique pour étudier les arbitrages entre des objectifs contradictoires de gestion (conservation, et viabilité économique et sociale) des pêcheries mixtes. Deux pêcheries mixtes sont analysées dans cette thèse : la pêcherie française mixte démersale du golfe de Gascogne et la pêcherie crevettière australienne du Nord (NPF). Ces deux pêcheries sont multi-espèces, et utilisent des stratégies multiples de pêche, induisant des impacts directs et indirects sur les écosystèmes. Cette thèse propose une application de la co-viabilité stochastique à ces deux cas, en prenant en compte leur histoire, leur contexte socio-politique et les différences dans les stratégies et objectifs de gestion. Les résultats suggèrent que le status quo peut être considéré comme une stratégie biologiquement durable mais socio économiquement à risque dans les deux pêcheries (ainsi qu’à risque écologique dans le cas de la pêcherie australienne). Les simulations réalisées pour le golfe de Gascogne permettent de comparer les arbitrages associés à différentes réductions de capacités par flottille et de montrer qu’il existe des solutions de gestion permettant la co-viabilité du système (viabilité biologique des différentes espèces considérées et viabilité socio-économique des flottilles) contrairement à des stratégies de gestion mono-spécifiques ou basées sur la maximisation de la rente. Dans la pêcherie crevettière australienne, l’analyse montre que les stratégies de diversification permettent de limiter le risque économique contrairement aux stratégies plus spécialisées. / Empirical evidence and the theoretical literature both point to stock sustainability and the protection of marine biodiversity as important fisheries management issues. Decision-support tools are increasingly required to operationalize the ecosystem-based approach to fisheries management. These tools need to integrate (i) ecological and socio-economic drivers of changes in fisheries and ecosystems; (ii) complex dynamics; (iii) deal with various sources of uncertainty; and (iv) incorporate multiple, rather than single objectives. The stochastic co-viability approach addresses the trade-offs associated with balancing ecological, economic and social objectives throughout time, and takes into account the complexity and uncertainty of the dynamic interactions which characterize exploited ecosystems and biodiversity. This thesis proposes an application of this co-viability approach to the sustainable management of mixed fisheries, using two contrasting case studies: the French Bay of Biscay (BoB) demersal mixed fishery and the Australian Northern Prawn Fishery (NPF). Both fisheries entail direct and indirect impacts on mixed species communities while also generating large economic returns. Their sustainability is therefore a major societal concern. A dynamic bio-economic modelling approach is used to capture the key biological and economic processes governing these fisheries, combining age- (BoB) or size- (NPF) structured models of multiple species with recruitment uncertainty, and multiple fleets (BoB) or fishing strategies (NPF). Economic uncertainties relating to input and output prices are also considered. The bioeconomic models are used to investigate how the fisheries can operate within a set of constraints relating to the preservation of Spawning Stock Biomasses (BoB) or Spawning Stock Size Indices (NPF) of a set of key target species, maintenance of the economic profitability of various fleets (BoB) or the fishery as a whole (NPF), and limitation of fishing impacts on the broader biodiversity (NPF), under a range of alternative scenarios and management strategies. Results suggest that under a status quo strategy both fisheries can be considered as biologically sustainable, while socio-economically (and ecologically in the NPF case) at risk. Despite very different management contexts and objectives, viable management strategies suggest a reduction in the number of vessels in both cases. The BoB simulations allow comparison of the trade-offs associated with different allocations of this decrease across fleets. Notably, co-viability management strategies entail a more equitable allocation of effort reductions compared to strategies aiming at maximizing economic yield. In the NPF, species catch diversification strategies are shown to perform well in controlling the levels of economic risk, by contrast with more specialized fishing strategies. Furthermore analyses emphasize the importance to the fishing industry of balancing global economic performance with inter-annual economic variability. Promising future developments based on this research involve the incorporation of a broader set of objectives including social dimensions, as well as the integration of ecological interactions, to better address the needs of ecosystem-based approaches to the sustainable harvesting of marine biodiversity.

Die vermiedene tropische Entwaldung und zusätzliche Aufforstungen sind von zentraler Bedeutung für die Klimawandelvermeidung, üben aber zusätzlichen Druck auf die globalen Landressourcen zur Produktion von Nahrungsgütern, Futtermittel, Fasern, Bioenergie und Rundholz dar. Die Ziele der Studie beziehen sich auf die Analyse der Verzichtskosten in der Land- und Forstwirtschaft sowie das Potential zur Klimawandelvermeidung in globalen Wäldern durch normative und marktbasierte Klimaschutzprogramme. Das globale ökonomische Landnutzungsmodell ''Model of Agricultural Production and its Impact on the Environment'' (MAgPIE) wurde um eine konsistente Landnutzungsdatenbank und den Forstsektor erweitert. Es simuliert die räumlich-explizite Landnutzung und deren Änderungen während die Kosten land- und forstwirtschaftlicher Produktion unter gegebener Nachfrage nach Gütern geschätzt werden. Szenarien zu Klimaschutzmaßnahmen werden verglichen mit Referenzszenarien über Zeithorizonte bis zum Jahr 2100. Die Ergebnisse verweisen auf ein begrenztes Mitigationspotential normativen tropischen Waldschutzes zu geringen zusätzlichen Kosten in der Landwirtschaft. Lateinamerika profitiert von ausreichenden Landreserven und geringem Anstieg in der Güternachfrage und geringer Referenzentwaldung. Die Verlagerung von Emissionen durch regionalen Waldschutz hat Auswirkungen auf die sektoralen Produktionskosten und verringert das globale ökonomische Potential. Die Schlussfolgerungen betreffen 1) den Bedarf an substantieller Ertragssteigerung in Sub-Sahara Afrika als Voraussetzung für die erfolgreiche Umsetzung vermiedener Entwaldung, 2) die erhöhte Gefahr der Verlagerung von Emissionen aus Entwaldung durch die Umsetzung regionaler Klimaschutzprogramme und der Liberalisierung des Holzhandels, 3) das hohe ökonomische Potential integrierter Klimaschutzprogramme zu moderaten Verzichtskosten, sowie 4) die Notwendigkeit zusätzlicher Forschung bezüglich der Unsicherheiten in Parametern und Modellprozessen. / Avoiding tropical deforestation and additional afforestation are of primary importance for climate change mitigation but exert additional pressure on global land resources for the production of food, feed, fibre, bioenergy and timber. The study objectives relate to the analysis of the foregone economic benefits, the opportunity costs, in agriculture and forestry and the climate change mitigation potential of global forests in normative and market-based programmes. The global economic ‘Model of Agricultural Production and its Impact on the Environment'' (MAgPIE) has been extended by a consistent land use database and the forestry sector. It simulates spatially-explicit land use and land use changes while estimating the costs of production in agriculture and forestry to satisfy a prescribed demand. Climate change mitigation scenarios are contrasted to baselines for time horizons up to the year 2100. The results show the limited mitigation potential of normative forest conservation in tropical regions at low additional costs in agriculture. Latin America benefits from sufficient land endowments and low increases in crop demand leading to relatively low baseline deforestation. The displacement of carbon emissions between regions impacts the regional agriculture and forestry production costs and reduces the global economic potential. The conclusions pertain to the 1) need for high rates of yield increase in Sub-Saharan Africa as a precondition for successfully avoided deforestation, 2) increased threat of regional carbon emission leakage from implementing mitigation programmes and liberalized trade of timber, 3) high economic potential of climate change mitigation from integrating afforestation and avoided deforestation at moderate costs, and 4) additional research needs to account for significant uncertainties from growth and cost parameters and model processes.

En France, où les droits de pêches ne sont pas transférables, la gestion des quotas de pêche est essentiellement déléguée aux organisations de producteurs (OP), lesquelles se voient attribuer des allocations collectives et sont responsables de la gestion des possibilités de pêche de leurs adhérents. On peut ainsi s’interroger sur la manière dont la présence des OP au sein des institutions peut permettre d’améliorer les performances écologiques,économiques et sociales de la gestion des pêches en comparaison avec d’autres formes institutionnelles telles que les systèmes de quotas individuels transférables (QIT). Les recherches de thèse, comprenant une partie théorique et s’appuyant sur le cas de la pêcherie de sole du golfe de Gascogne pour les applications empiriques,sont organisées autour des questions suivantes : (1) Par quels mécanismes les OP peuvent-elles permettre d’améliorer le respect des réglementations et influencer l’émergence de normes sociales ? (2) Quels sont les effets redistributifs de la gestion des quotas par les OP ? (3) Comment les mécanismes de gestion des quotas par les OP peuvent-ils être intégrés dans la modélisation bio-économique pour l’évaluation d’impact de scénarios de gestion ? Les analyses développées établissent l’intérêt de prendre en compte des contraintes induites par différents arrangements institutionnels et les résultats sont notamment examinés au regard des trois dimensions (écologique, économique et sociale) nécessaires à la gestion durable des pêches. Les compromis entre ces différentes dimensions sont mis en évidence dans le cadre de scénarios prospectifs visant une meilleure compréhension des enjeux liés à la gestion des pêches. / In France, where fishing rights are non-transferable, the management of fishing quotas is essentially delegated to producer organizations (POs). POs are granted collective allocations based on the aggregate fishing rights of their members and are then responsible for managing their fishing opportunities. The goal of this research, which contains theoretical developments as well as empirical analyses applied to the Bay of Biscay sole fishery, is to determine how outcomes of fisheries management are altered by the presence of POs within institutions as compared to alternative governance systems such as individual transferable quotas (ITQs). This dissertation notably brings together bio-economic approaches and institutional analyses to better anticipate the ecological, economic and social impacts of potential governance options. The research questions are the following: (1) What mechanisms could ensure a high level of compliance and what are the potential gains of placing the POs between the regulator and the fishermen? (2) What are the distributional effects of catch share management by POs? (3) What is the added value of integrating institutional arrangements involving POs into bio-economic modelling for the impact assessment of catch share management options? The analyses that were developed establish the ability of institutional design to influence outcomes in catch share systems in terms of compliance, distribution, and ecological-socioeconomic trade-offs achieved by alternative management options.