Resource management regulations, such as those associated with the establishment of protected areas, can increase vulnerability and compromise individual and collective agency for adaptation. In this article, we comparatively analyse how four rural communities located within two biosphere reserves in Mexico and Bolivia experience vulnerability and adaptation to global change. We use focus groups, interviews and scoring exercises to analyse the influence of reserve management practices on locally perceived changes and stresses on livelihoods, and to discuss communities' coping and adaptation strategies. We show that both reserves are perceived as a source of stress but somewhat differently. In Mexico, communities feel vulnerable to the reserve's regulations but less to climatic and economic stresses, whereas in Bolivia communities perceive the insufficient enforcement of the reserve's rules as the most relevant stress to their livelihoods. Most of household-based and collective adaptations to environmental change have been adopted without the support of the biosphere reserves. We discuss how and why the biosphere reserves contribute to local vulnerability and why their role in enhancing local adaptation is limited.