Using Primary Forests as Baselines to Assess the Effect of Forest Management on Biodiversity: A Multi-Taxonomic European Perspective

Forests, which contain a large share of the world’s terrestrial biodiversity, have and are still being converted for various land-use. Assessment of human impact on forest biodiversity requires knowledge of the baseline state – the biodiversity found in natural ecosystems. Primary forests, which have had little to no direct human impacts, may represent this baseline state. In this systematic literature review we assess the effect of forest management on the species richness of multiple taxonomic groups (epiphytic lichen, understory vascular plant, saproxylic beetle) at the European scale, while using primary forests as references. By reviewing European studies comparing species richness in primary and managed forests, we quantified effect sizes and summarized the comprehensiveness, representativeness, and scale of existing research. Our review identified a shortage of large-scale studies and large variability in study designs, limiting our ability to confidently compare and generalize findings across Europe. Hence, using the current European literature, it is challenging to assess the effect of forest management on species richness. To enable more robust analyses at this spatial scale, increased efforts to map primary forests and adopt standardized biodiversity assessment guidelines across Europe may be helpful.