Estimating retention benchmarks for salvage logging to protect biodiversity

Abstract

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. 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 75 ± 7% (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.

Connectivity and succession of open structures as a key to sustaining light‐demanding biodiversity in deciduous forests

“…Disturbances are essential for maintaining forest biodiversity and environmental heterogeneity by creating short‐ and long‐lasting gaps, patches of early seral stages or open habitats with low or no canopy cover (Bouget & Duelli, 2004; Hilmers et al., 2018; Swanson et al., 2011). In comparison to the surrounding forests, disturbed patches often host rich and specialised biota, especially bats, beetles, lichens and moths that exploit the increased availability of sunlight, soil nutrients, deadwood, non‐woody vegetation or nectar resources (Douda et al., 2017; Muscolo et al., 2014; Sariyildiz, 2008; Thorn et al., 2020; Wermelinger et al., 2002). However, most information on the effect of natural disturbances on forest biota comes from the boreal zone or montane coniferous forests, where large‐scale, stand‐replacing disturbances prevail (Boucher et al., 2012; Bouget, 2005; Gibb et al., 2006; Gibb et al., 2013; Thorn et al, 2014; 2017).…”

Resilience impacts of a secondary disturbance: Meta‐analysis of salvage logging effects on tree regeneration

“…First, tree density was more negatively affected by salvage logging the higher the intensity of logging. This highlights that tree retention may help mitigate the potential impacts of logging even in naturally disturbed ecosystems (Gustafsson et al, 2012; Thorn et al, 2020). Second, salvage logging effects on regeneration density were most negative after beetle outbreaks, intermediate after windthrow, and highest after fire.…”

The effects of forest management on biodiversity in the Czech Republic: an overview of biologists’ opinions

“…Moreover, an increased occurrence and severity of these disturbances particularly in conifer forests has been predicted in relation to climatic changes (Seidl et al 2017). Since snags and windthrown trees are usually cleared as a part of salvage logging and large clear-cut areas are formed, it is necessary to retain (on a landscape level) those snags that do not threaten health and safety since extensive salvage logging not only supports further disturbances but also causes additional damage to biodiversity (Thorn et al 2020).…”