Authors: Hekkala, Anne-Maarit; Sjögren, Jörgen;Jönsson, Mari;Kärvemo, Simon;Strengbom, Joachim;

Biodiversity assessment is a fundamental part of sustainable forestry and biodiversity conservation. Nevertheless, measuring biodiversity is far from simple and remains a challenge for practitioners who must make management decisions and report the national state of biodiversity at the EU-level. We tested if habitat heterogeneity or a set of habitat amount measures could predict biodiversity in Swedish boreal forests. We used 77 mature coniferous forest stands varying from simple production forests to valuable woodland key habitats to evaluate the relationships between habitat diversity, habitat amount and richness and abundance of species of conservation concern (SoCC) belonging to fungi, bryophytes, lichens and vascular plants. We found stand level habitat heterogeneity to be the best measure to explain the richness of SoCC, but when only red-listed species were included, deadwood volume and age of the oldest tree proved to be more precise proxies. However, the more intensively managed southern region revealed an alarming species loss; despite the habitat availability, the average species richness was only half of the richness in the north. We conclude that habitat heterogeneity can be used as a reliable proxy of the species of conservation concern, but it must not be used to prioritize conservation between geographical regions.