The aim of the study was to determine the dynamics of wood decay using acoustic tomography. Different devices are use to estimate range of internal damage of the tree caused by wood rot as is possible to find in literature. For purpose of these measurements were used devices ArborSonic Decay Detector 3D and Resistograph IML F400-S. Thesis was divided in two main sections. The first section was focused on practical testing of both devices, acquiring knowledge about research procedure and also learning about possible mistakes to be avoid during research. It was necessary to perform two measurements at a time interval of approximately one year. In first year, 70 samples of Norway spruce (Picea abies) were measured and evaluated their health and vitality status. Trees, that had symptoms of fungi wood decay, were measured in the second year once more. Subsequently, the ranges and changes of inner damages by wood fungi were determined and compared results from both devices. The second part was focused on comparison of the graphical results of the range of decay in the Fakopp 3D software with the actual state of the affected tree trunk. An obtained result showed the dynamics of wood decay in years 2018-2019 and therefore was possible to determine the dynamics of wood decay in Norway spruce wood, verify the influence of the basic parameters and also to compare the graphical image of the decay range with the real status in the trunk. The average change of decay range of evaluated Norway spruce trees was 3,32%. It was found out, that Acoustic tomograph overestimated cavity section in 21 cases, which was 84 % in comparison with Resistograph. This overestimation fact was was also proved by graphical result from Fakopp 3D software, which was compared with real status of trunk. The use of device methods for assessment of tree status and preparation for tree care plans were more described in Discussion chapter.

Effekten av torka på gran kan var stor. Sommaren 2018 var en av de torraste och varmaste somrarna på länge. En sådan period påverkar ofta granars vitalitet negativt och kan leda till en ökad risk för angrepp av granbarkborre. Denna studie har undersökt hur årsringsbredden på gran har förändrats till följd av torka genom att jämföra årsringsbredder före torkperioden med de efter. Mätningar genomfördes med en resistograf som genererade datafiler som sedan sammanställdes och analyserades, främst med hjälp av Excel. Vidare noterades markfuktighet, bonitet och angrepp av granbarkborre. Dessa faktorer jämfördes med varandra med syfte att finna eventuella samband. Studiens resultat visar att torkperioden 2018 haft en stor inverkan på granars vitalitet. Dessutom har samband mellan torrare bestånd och antal granar angripna av granbarkborre kunnat påvisas. Samband mellan minskad årsringsbredd och angrepp av granbarkborre har ej kunnat fastställas.