Stump and Site Factor Analysis After Sanitary Logging of Bark Beetle-Infested Forests

Coniferous forests cover 41% of Bosnia and Herzegovina, with Norway spruce ( Picea abies ) being an ecologically and economically important species. Bark beetles, especially the European spruce bark beetle ( Ips typographus ), pose a major threat, often causing large-scale dieback. Factors such as wind, drought, terrain exposure, and slope can increase susceptibility to outbreaks. This study aimed to assess the influence of these factors on forest health in bark beetle outbreak areas, based on stump measurements after sanitary logging.Fieldwork was conducted in spring 2024 on five known bark beetle hotspots managed by “Šumsko privredno društvo Zeničko-dobojskog kantona” d.o.o. Zavidovići. Data collected included stump diameter, wood decay, bark thickness, tree coordinates (via AlpineQuest), exposure, and slope. Analyses were performed in STATGRAPHICS Plus using one-way ANOVA and Bonferroni correction.A total of 507 stumps were analyzed. About 81% were in diameter classes 31–50 cm and 51–80 cm and nearly 48% showed central wood decay. Terrain exposure and slope significantly influenced stump diameters, with the largest averages on SW exposure and 2–5% slopes. Stump diameter also significantly affected decay size, while bark thickness showed no significant variation across exposure or slopes.This research confirmed that Norway spruce in diameter size categories 31–50 cm and 51–80 cm is most vulnerable to bark beetle attacks. This susceptibility is further intensified if trees are located on south-facing, moderate slopes. Central wood decay was present in nearly half of the observed tree stumps, leading to the conclusion that its presence is another predisposing factor for bark beetle attacks. Bark thickness on the observed tree stumps did not vary significantly on different terrains, which is a result that differed from the results obtained in other similar studies.