On the eve of the World Summit on Sustainable Development, it is timely to assess progress over the 10 years since its predecessor in Rio de Janeiro. Loss and degradation of remaining natural habitats has continued largely unabated. However, evidence has been accumulating that such systems generate marked economic benefits, which the available data suggest exceed those obtained from continued habitat conversion. We estimate that the overall benefit:cost ratio of an effective global program for the conservation of remaining wild nature is at least 100:1.

SUMMARYThe concept of ecosystem services (ES), the benefits humans derive from ecosystems, is increasingly applied to environmental conservation, human wellbeing and poverty alleviation, and to inform the development of interventions. Payments for ecosystem services (PES) implicitly recognize the unequal distribution of the costs and benefits of maintaining ES, through monetary compensation from 'winners' to 'losers'. Some research into PES has examined how such schemes affect poverty, while other literature addresses trade-offs between different ES. However, much evolving ES literature adopts an aggregated perspective of humans and their well-being, which can disregard critical issues for poverty alleviation. This paper identifies four issues with examples from coastal ES in developing countries. First, different groups derive well-being benefits from different ES, creating winners and losers as ES, change. Second, dynamic mechanisms of access determine who can benefit. Third, individuals' contexts and needs determine how ES contribute to well-being. Fourth, aggregated analyses may neglect crucial poverty alleviation mechanisms such as cash-based livelihoods. To inform the development of ES interventions that contribute to poverty alleviation, disaggregated analysis is needed that focuses on who derives which benefits from ecosystems, and how such benefits contribute to the well-being of the poor. These issues present challenges in data availability and selection of how and at which scales to disaggregate. Disaggregation can be applied spatially, but should also include social groupings, such as gender, age and ethnicity, and is most important where inequality is greatest. Existing tools, such as stakeholder analysis and equity weights, can improve the relevance of ES research to poverty alleviation.

Environmental decisions made by individuals, civil society, and the state involve questions of economic efficiency, environmental effectiveness, equity, and political legitimacy. These four criteria are constitutive of the economic, social, and environmental dimensions of sustainable development, which has become the dominant rhetorical device of environmental governance. We discuss the tendency for disciplinary research to focus on particular subsets of the four criteria, and argue that such a practice promotes solutions that do not acknowledge the dynamics of scale and the heterogeneity of institutional contexts. We advocate an interdisciplinary framework for the analysis of environmental decisionmaking that seeks to identify legitimate and context-sensitive institutional solutions producing equitable, efficient, and effective outcomes. We demonstrate the usefulness of our approach by using it to examine decisions concerning contested nature conservation and multiple-use commons in the management of Hickling Broad in Norfolk in the United Kingdom. We conclude that interdisciplinary approaches enable the generalisation and transfer of lessons in a way that respects the specifics and context of the issue at hand.

ABSTRACT. Although ecosystem services are increasingly recognized as benefits people obtain from nature, we still have a poor understanding of how they actually enhance multidimensional human well-being, and how well-being is affected by ecosystem change. We develop a concept of "ecosystem service elasticity" (ES elasticity) that describes the sensitivity of human well-being to changes in ecosystems. ES Elasticity is a result of complex social and ecological dynamics and is context dependent, individually variable, and likely to demonstrate nonlinear dynamics such as thresholds and hysteresis. We present a conceptual framework that unpacks the chain of causality from ecosystem stocks through flows, goods, value, and shares to contribute to the well-being of different people. This framework builds on previous conceptualizations, but places multidimensional well-being of different people as the final element. This ultimately disaggregated approach emphasizes how different people access benefits and how benefits match their needs or aspirations.Applying this framework to case studies of individual coastal ecosystem services in East Africa illustrates a wide range of social and ecological factors that can affect ES elasticity. For example, food web and habitat dynamics affect the sensitivity of different fisheries ecosystem services to ecological change. Meanwhile high cultural significance, or lack of alternatives enhance ES elasticity, while social mechanisms that prevent access can reduce elasticity.Mapping out how chains are interlinked illustrates how different types of value and the well-being of different people are linked to each other and to common ecological stocks. We suggest that examining chains for individual ecosystem services can suggest potential interventions aimed at poverty alleviation and sustainable ecosystems while mapping out of interlinkages between chains can help to identify possible ecosystem service trade-offs and winners and losers. We discuss conceptual and practical challenges of applying such a framework and conclude on its utility as a heuristic for structuring interdisciplinary analysis of ecosystem services and human wellbeing.