Evaluating retention forestry 10 years after its introduction in temperate forests regarding the provision of tree-related microhabitats and dead wood

Abstract The individual or grouped retention of habitat trees in managed multiple-use forests has become an approach used to protect biodiversity-related structural attributes typically found old close-to-nature forests. This study focuses on the effect one such Baden-Württemberg, Germany, ten years after its introduction. Specifically, we asked: (1) How effective are tree groups (HTGs) at providing large living (LLTs > 80 cm DBH), tree-related microhabitats (TreMs), and dead wood?, (2) which stand variables have greatest influence occurrence TreMs? For this purpose, inventoried 326 HTGs 94 reference plots dominated by most widely occurring native conifer broadleaf species, silver fir ( Abies alba ) European beech Fagus sylvatica ). In accordance with our hypotheses, LLTs TreMs were significantly more abundant than both forest types. More importantly, when retaining 5% area as (a common level), woodpecker cavities, rot-holes exposed heartwood increased level while volume almost tripled, snags 25%. However, quantities these two remain below minimum thresholds recommended scientific literature. A conversion 15–25% into is needed increase abundance concavities, sapwood, crown wood short term. At single-tree level, diameter (DBH), vitality neighborhood competition had a significant modeled TreM abundance. age amount snags, whereas richness declined density. Ten introducing approach, stands comprised important those without. Selecting high low density that also include mix LLTs, some low-vitality could further improve practice.