This study investigates governance and socio-ecological resilience in Lake Gahar Biosphere Reserve, located in Iran’s Central Zagros, where growing tourism pressure, environmental degradation, and weak institutional coordination have intensified tensions between conservation and development. Although Biosphere Reserves are intended to link biodiversity protection with sustainable development through participatory governance, their effectiveness is often limited by management systems that insufficiently integrate ecological, social, institutional, and cultural dimensions. In response, this research develops and applies a multidimensional participatory framework to assess resilience and governance capacity in Lake Gahar. The study employs a mixed-methods case study design, drawing on semi-structured interviews with key stakeholders, participatory workshops, and resilience-based indicators to examine ecological integrity, institutional effectiveness, socio-economic pressures, climate vulnerability, and ecosystem services. The findings show that the reserve retains some ecological recovery potential, but this capacity is increasingly weakened by cumulative pressures, including declining water quality, biodiversity loss, invasive species, and climate-related stress. The results further indicate that tourism has exceeded the area’s ecological carrying capacity while generating uneven benefits for local communities, thereby reinforcing the imbalance between environmental protection and livelihood needs. Governance assessment points to weak regulatory enforcement, institutional fragmentation, and limited stakeholder participation, all of which constrain adaptive management and undermine long-term resilience. The study argues that Lake Gahar’s vulnerability is shaped not only by ecological pressures but also by institutional deficiencies that impede coordinated and inclusive decision-making. It concludes that strengthening resilience requires a transition from fragmented, top-down management to adaptive, participatory, and locally grounded governance capable of aligning conservation priorities with community interests and climate adaptation. More broadly, the study provides a transferable analytical framework for understanding and strengthening resilience in biosphere reserves facing comparable governance and sustainability challenges, particularly in understudied regions of the Global South.