Ecological Constraints on Tropical Forest Recovery Challenge the "Long-Term" Vision of the Kunming-Montreal Global...

The Kunming-Montreal Global Biodiversity Framework (GBF) outlines targets for protecting and restoring biodiversity by 2030, with the vision of "living in harmony with nature" by 2050. Although the 20-year vision clearly is aspirational, we emphasize that many forest attributes crucial for biodiversity-such as the abundance of large trees and the availability of dead wood-recover over much longer timescales. In a restored tropical forest, we estimate that it may require about 57 years to reach densities of large trees comparable to pristine forests (>75 cm DBH) and up to 144 years for the largest trees to attain similar sizes. Twenty years is also insufficient to restore dead-wood stocks, but as trees mature and die, they can replenish the pool of large dead wood essential for biodiversity. Achieving GBF goals will require policies and management strategies that recognize ecological timescales and commit to long-term restoration and protection.