Treating knowledge as a conservation asset to resolve present-future biodiversity trade-offs.

Conservation planning must allocate limited resources under substantial uncertainty about species interactions. A central dilemma is whether prioritization should be guided by phylogenetic diversity (PD), which preserves long-term evolutionary potential, or functional diversity (FD), which supports current ecosystem functioning. Because PD and FD are often weakly correlated, fixed prioritization schemes can misallocate effort when ecological information is incomplete. We develop a dynamic allocation framework in which the conservation objective is fixed, but the biodiversity proxy guiding decisions adapts to the level of interaction knowledge. When interaction information is limited, PD-based rankings are more robust to uncertainty; as interaction knowledge accumulates, rankings based on FD become increasingly reliable. We evaluate this framework using a 148-year Northeast Atlantic fish stomach time series and simulations on synthetic food webs. Across both empirical and simulated ecosystems, the adaptive strategy consistently produces higher post- disturbance diversity than fixed-weight PD-FD strategies and no-intervention baselines. This indicates that the PD-FD trade-off should be conditioned on the prevailing level of ecological knowledge, rather than fixed ex ante.