Commercialized hunting and trade of wildlife are the largest threats to mammal populations and human livelihoods in the Congo Basin. It is widely recognized that the lives of humans and wildlife in this region are inextricably intertwined. However, few studies have attempted to integrate both human and wildlife dimensions using ethnographic data to better contextualize the trade and its ecological impacts. This paper outlines a methodological approach that combines ethnographic research, ecological line transects and market surveys in the Dzanga Sangha Reserve (Central African Republic). Results from each research component are reported separately in order to provide examples of how each would answer specific questions about the status of wildlife populations and the scale of hunting within a protected area. The integrated analysis of ethnographic, market and ecological datasets clarifies synergistic impacts operating in the region and provides a more nuanced understanding of changes in both the forest and the market based on information gleaned from hunting practices and hunter interviews. This research demonstrates the potential pitfalls of using a singular approach to make recommendations on complex human-environment issues. Such cross-disciplinary mixed-methods approaches will further understandings of dynamic wildlife populations and forge more informed environmental policy recommendations.

The current rapid decline in biodiversity in human-dominated agricultural landscapes, both in Europe and worldwide, impacts on the provision of environmental services essential to human well-being. There is, therefore, a pressing need to develop and implement incentive-based conservation policies to counteract the ongoing loss of biodiversity. This paper presents results of a regionally-scaled conservation procurement auction, a type of incentive-based payments for environmental services (PES), targeted at the conservation of arable plant diversity. By matching arable fields that were participating in the PES scheme to control fields that were not enrolled in the PES scheme, two critical key characteristics were addressed, namely additionality and bid prices. Additionality was addressed by evaluating whether fields for which PES were issued had significantly higher arable plant diversity than the matched control fields. The cost-effectiveness of a conservation auction increases if payments compensate just farmers’ opportunity costs (in terms of forgone production); bid prices of participating farmers were thus also evaluated to determine whether they were related to their individual opportunity costs. The PES scheme proved to be highly effective in ensuring environmental services delivery through enhanced arable plant diversity on participating fields. In contrast, the potential of the proposed conservation auction design to raise cost-effectiveness has to be questioned, because bid prices submitted in this scheme substantially exceeded individual farmers’ opportunity costs. Therefore, bid prices were most likely influenced by socioeconomic factors other than opportunity costs. This case study illustrates potentials and pitfalls associated with the implementation of a PES scheme and, by evaluating the effectiveness of the scheme, contributes to an improved understanding of incentive-based mechanisms for both policymakers and practitioners involved in PES scheme design and implementation.

Papua New Guinea (PNG) has been the site of a great deal of scientific work, and a fair amount of interdisciplinary debate, within the broad field of historical ecology, which encompasses the study of indigenous society-environment relationships over different time periods. However, this in itself provides no guarantee that scientists engaged in such debate will have a greater influence on the formulation of environmental conservation policies in a state where indigenous decision makers now hold the levers of political power. Five environmental policy paradigms which have emerged in the course of public debate about environmental conservation in PNG over the past half century; the wildlife management, environmental planning, biodiversity conservation, ecosystem assessment, and carbon sequestration paradigms. Each paradigm has framed a distinctive form of interdisciplinary debate about indigenous society-environment relationships within a contemporary political framework. However, a further connection can be drawn between the role of interdisciplinary debate in an evolving national policy framework and the history of scientific debate about the nature of indigenous society-environment relationships in the pre-colonial era. This connection places a distinctive emphasis on the relationship between indigenous agricultural practices and management of the national forest estate for reasons which are themselves a contingent effect of the nature of European colonial intervention over the course of the last century and a half. This particular bias in the relationship between historical ecology and environmental policy has lasted down to the present day. PNG's environmental policy problems are unlikely to have any rational or sensible solution in the absence of a better scientific understanding of the complexity of indigenous society-environment relationships. Scientists need to understand the complexity of the environmental policy process as a historical process in its own right in order to work out which policy problems offer both the scope and the incentive to sustain specific forms of interdisciplinary debate that are likely to produce better policy outcomes.

The operation and longevity of hydropower dams are often negatively impacted by sedimentation. Forest conservation can reduce soil erosion, and therefore efforts to maintain upstream forest cover within a watershed contribute to the economic life span of a hydropower facility. The cost of forest conservation can be viewed as an investment in hydropower and be financed via a payment for ecosystem services (PES) scheme. A novel modelling framework is used to estimate payments for forest conservation consisting of: (1) land-use change projection; (2) watershed erosion modelling; (3) reservoir sedimentation estimation; (4) power generation loss calculation; and (5) PES scheme design. The framework was applied to a proposed dam in Cambodia (Pursat 1). The estimated net present value of forest conservation was US$ 4.7 million when using average annual climate values over 100 years, or US$ 6.4 million when considering droughts every eight years. This can be remunerated with annual payments of US$ 4.26 ha−1 or US$ 5.78 ha−1, respectively, covering forest protection costs estimated at US$ 0.9 ha−1 yr−1. The application of this type of PES represents a rational option that allows for conservation and development of hydropower watersheds susceptible to erosion and sedimentation.

Mangroves are an imperilled biome whose protection and restoration through payments for ecosystem services (PES) can contribute to improved livelihoods, climate mitigation and adaptation. Interviews with resource users in three Solomon Islands villages suggest a strong reliance upon mangrove goods for subsistence and cash, particularly for firewood, food and building materials. Village-derived economic data indicates a minimum annual subsistence value from mangroves of US$ 345–1501 per household. Fish and nursery habitat and storm protection were widely recognized and highly valued mangrove ecosystem services. All villagers agreed that mangroves were under threat, with firewood overharvesting considered the primary cause. Multivariate analyses revealed village affiliation and religious denomination as the most important factors determining the use and importance of mangrove goods. These factors, together with gender, affected users’ awareness of ecosystem services. The importance placed on mangrove services did not differ significantly by village, religious denomination, gender, age, income, education or occupation. Mangrove ecosystem surveys are useful as tools for raising community awareness and input prior to design of PES systems. Land tenure and marine property rights, and how this complexity may both complicate and facilitate potential carbon credit programmes in the Pacific, are discussed.