EFFECTS OF NORWAY SPRUCE STAND CHARACTERISTICS ON THE INTENSITY OF IPS TYPOGRAPHUS (L.) INFESTATION IN 2021–2025

Abstract

The aim of the study is to assess how the taxonomic parameters of spruce forests are related to the intensity of damage caused by the European spruce bark beetle (Ips typographus L.) in 2021–2025. The data on Norway spruce (Picea abies (L.) H. Karst.) stands in the Žalioji giria forest complex of the Paežerys Forest District of the Panevėžys Regional Division of the State Forest Enterprise were analyzed. Damage was assessed based on recorded pest outbreaks, their extent, and the proportion of damaged trees compared to the overall structure of the spruce forest. It was found that damage is concentrated in medium-density and dense (0.7–0.8 thinning) spruce forests, as well as in older stands: 5–8 age classes. The structure of the damaged stands revealed an excessive representation of normal moisture fertility (Nc) sites compared to their share in the entire stand. In addition, it was found that, according to the proportion of spruce in the species composition of the forest stand, the largest proportion of damage caused by the European spruce bark beetle (Ips typographus L.) occurred in pure spruce forests. Thus, the results confirm that when planning sustainable forestry measures, it is necessary to differentiate monitoring and prevention according to the density, age, species composition, trophic-hydrological regime, and site quality of the forest stand.