Ecosystem Services, Biodiversity Conservation, and Human Well-Being Trade-offs in the Cross River State Biodiversity Hotspot: A Decision Science Approach

Cross River State's biodiversity hotspot contains globally irreplaceable ecological assets including Nigeria's largest remaining lowland rainforest and critical habitats for the critically endangered Cross River gorilla, yet conservation decisions require navigating complex trade-offs between biodiversity outcomes, ecosystem service provisioning, and the development aspirations of human communities dependent on forest resources. This doctoral research applies decision science theory and methods to analyse ecosystem services and biodiversity conservation trade-off structures in Cross River State's forest landscape and co-develop governance arrangements for multi-objective landscape management. The decision science approach integrates spatially explicit ecosystem services assessment using InVEST models calibrated for Cross River forest conditions, structured decision making methodology applied through participatory stakeholder processes with 120 participants representing conservation organisations, government agencies, and 14 forest-adjacent communities, and Bayesian decision network modelling to represent uncertainty in conservation outcome predictions. Biodiversity monitoring draws on occupancy modelling from camera trap and transect survey data across 52 monitoring units. Trade-off analysis reveals that strict protection scenarios optimise biodiversity outcomes and carbon sequestration but reduce provisioning service access by 38 percent for forest-adjacent communities, while community forestry scenarios improve livelihood outcomes but generate a 22 percent reduction in biodiversity conservation effectiveness compared to protected area scenarios. The structured decision making process identifies a portfolio of spatially differentiated management zones that approaches the Pareto-efficient frontier across competing objectives. Theoretical contributions advance the integration of decision science and ecosystem service science for biodiversity conservation governance. Keywords: trade-off analysis, biodiversity conservation, Cross River State, decision science, ecosystem services.