Simon Thorn, Anne Chao, Konstadin B. Georgiev, Jörg Müller, Claus Bässler, John L. Campbell, Castro Jorge, Yan-Han Chen, Chang-Yong Choi, Tyler P. Cobb, Daniel C. Donato, Ewa Durska, Ellen Macdonald, Heike Feldhaar, Jospeh B. Fontaine, Paula J. Fornwalt, Raquel María Hernández Hernández, Richard L. Hutto, Matti Koivula, Eun-Jae Lee, David Lindenmayer, Grzegorz Mikusinski, Martin K. Obrist, Michal Perlík, Josep Rost, Kaysandra Waldron, Beat Wermelinger, Ingmar Weiß, Michal Zmihorski, Alexandro B. Leverkus

• Forests are increasingly affected by natural disturbances. Subsequent salvage logging, a widespread management practice conducted predominantly to recover economic capital, produces further disturbance and impacts biodiversity worldwide. Hence, naturally disturbed forests are among the most threatened habitats in the world, with consequences for their associated biodiversity. However, there are no evidence-based benchmarks for the proportion of area of naturally disturbed forests to be excluded from salvage logging to conserve biodiversity. WeForests are increasingly affected by natural disturbances. Subsequent salvage logging, a widespread management practice conducted predominantly to recover economic capital, produces further disturbance and impacts biodiversity worldwide. Hence, naturally disturbed forests are among the most threatened habitats in the world, with consequences for their associated biodiversity. However, there are no evidence-based benchmarks for the proportion of area of naturally disturbed forests to be excluded from salvage logging to conserve biodiversity. We apply a mixed rarefaction/extrapolation approach to a global multi-taxa dataset from disturbed forests, including birds, plants, insects and fungi, to close this gap. We find that 757% (mean +/- SD) of a naturally disturbed area of a forest needs to be left unlogged to maintain 90% richness of its unique species, whereas retaining 50% of a naturally disturbed forest unlogged maintains 73 +/- 12% of its unique species richness. These values do not change with the time elapsed since disturbance but vary considerably among taxonomic groups. Salvage logging has become a common practice to gain economic returns from naturally disturbed forests, but it could have considerable negative effects on biodiversity. Here the authors use a recently developed statistical method to estimate that ca. 75% of the naturally disturbed forest should be left unlogged to maintain 90% of the species unique to the area.…