People living in landscapes of high conservation value are trapped between their dependence on natural resources to meet their development aspirations and the international pressure to conserve those resources. Although it is increasingly recognized that the conservation of some natural resources cannot happen without providing alternative livelihood solutions for local communities dependent on them, global experiences illustrate that the successful integration of conservation and development continues to be elusive. We adapted the approach based on "participatory vulnerability assessments" developed for climate change research and applied it to changes occurring in a conservation and development context. As a case study, we focused on a biodiversity hotspot in Southwest Cameroon that was recently designated a national park. We have shown that local communities believe their livelihood options will be reduced by the creation of the national park. Compensation measures such as ongoing community development plans are not yet impacting local livelihoods. Their success will only be measurable in the long term, whereas the restriction in access to the national park is already in effect. Meanwhile, new roads, and attractive prices for cash crops including cocoa, have created the opportunity for alternative sources of income that could have substantial impacts on smallholders as well as for conservation. The aim of this work was to identify risks and opportunities associated with conservation and development as a first step in improving decision making. Project activities are not implemented in isolation from the global context and are therefore not the only drivers of adaptation for local communities. One of our main findings is that new external stimuli, such as markets, may be highly influential, potentially undermining conservation and development efforts if not addressed in a properly designed adaptive process.