Thresholds for adding degraded tropical forest to the conservation estate

Journal article

Logged and disturbed forests are often viewed as degraded and depauperate environments - the poor cousins of primary forest. However, they are dynamic ecosystems that provide refugia for large amounts of biodiversity, so we cannot afford to underestimate their conservation value. Here, we present empirically defined thresholds for categorising the conservation value of logged forests, using one of the most comprehensive assessments of taxon responses to habitat degradation in any tropical forest environment. We analysed the impact of logging intensity on the individual occurrence patterns of 1,681 taxa belonging to 86 taxonomic orders and 126 functional groups in Sabah, Malaysia. Our results demonstrate the existence of two conservation- relevant thresholds. First, lightly logged forests (< 29 % biomass removal) retain significant conservation value and largely intact functional composition, and are therefore likely to recover their pre-logging values if allowed to undergo natural regeneration. Second, the most extreme impacts occur in heavily degraded forests with more than two-thirds (> 68 %) of their biomass removed, and are likely to require more expensive measures to recover their biodiversity value. Overall, our data confirm that primary forests are irreplaceable, but they also reinforce the message that logged forests retain significant conservation value that should not be overlooked.

Authors: Ewers, RM; Orme, CDL; Pearse, WD; Vollans, M; Slade, E

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Springer Nature
• Journal: Nature
• Volume: 631
• Issue: 8022
• Pages: 808–813
• Publication date: 2024-07-17
• Acceptance date: 2024-06-04
• DOI: 10.1038/s41586-024-07657-w
• EISSN: 1476-4687
• ISSN: 0028-0836
• Language: English