Position, size, and spatial patterns of bark stripping wounds inflicted by red deer (Cervus elavus L.) on Norway spruce using generalized additive models in Austria

Abstract Key message Bark stripping wounds by red deer ( Cervus elavus L.) were assessed on 9026 Norway spruce trees. Wound variables (length, width, area, relative height above ground, and angle) analysed using generalized additive models with spatial soap film smoothers. Wounds located at the uphill side of trees larger in summer than winter, wound size depended diameter breast (DBH) was spatially clustered. Context In Austria, elaphus is main species causing bark wounds. they often gnaw because food scarcity; summer, large pieces are detached to help digestion, water, nutrient uptake or as social behaviour. Aims The aim this study analyse width (i.e., divided stem circumference)) position (height angle deviation between azimuth from slope line)) for winter depending stand attributes describe patterns within stands. Methods A total 3832 nine experimental stands Picea abies (L.) Karst.) 47° 19’ N 14° 46’ E an elevation 1009–1622 m analysed. linear regression model fit length over each season. For all (wound length, position, (GAM) smoothers, which predict patterns, fitted. Results Of wounds, 79.5 % inflicted 20.5 summer. (31.9 cm ± 31.2 SD), (11.7 6.0 area (446.5 2 558.1 (0.177 0.098 SD) modelled peeling, DBH, tree coordinates. ground (119.4 cm± 26.8 (− 1.9 97.3 no meaningful GAM could be calculated. Seasonal differences more pronounced width; minimal, but significant. Analyses further showed that mainly Conclusion clustering sizes might reduce efficiency thinning remove heavily damaged bark-peeled increase number sample points required assess impact forest inventories. Also, location damages important information