Handbook of field sampling for multi-taxon biodiversity studies in European forests

Sustainable Forest Management (SFM) is crucial for biodiversity conservation. Although it should be assessed by monitoring the diversity of multiple taxonomic groups, most current SFM criteria and indicators account only for trees or consider indirect biodiversity proxies.Several projects performed multi-taxon sampling to investigate the effects of forest management on biodiversity, but through heterogeneous sampling approaches that hamper the identification of general trends, and the broad-scale inference for designing SFM.The COST Action BOTTOMS-UP (CA18207) established a network of researchers involved in 41 projects on European forest multi-taxon biodiversity across 13 European countries. We provide an overview of the sampling approaches to multi-taxon biodiversity, standing trees and deadwood in the form of an operational handbook for nine different taxonomic groups and for the sampling of standing trees and lying deadwood. For each of these forest components, we provide two standards that differ in spatial scale and effort, and give specific instructions for the comparability across standards, taxonomic groups and studies. This handbook derives from an effort of networking and synthesis and represents a pragmatic synthesis and an important step forward to direct monitoring of forest biodiversity, in Europe and elsewhere