The current state of forest trees and stands is under increasing pressure from ongoing climate change, which is reflected in the increasing incidence of extreme weather events. It is important to know the reactions of forest trees to changed conditions and to cope with new conditions through thorough preparation of forest ecosystems. The diploma thesis deals with the monitoring and analysis of seasonal and daily circumference changes in the and stem water status as part of the growth process of trees. The research was carried out in the Borová hora Arboretum (350 m a.s.l., Zvolenská kotlina, central Slovakia). The locality represents the 2nd forest vegetation stage. Stem circumference changes of Silver fir (Abies alba) and Norway spruce (Picea abies) were monitored continuously using dendrometers DRL 26 with automatic data storage. From the measured data of circumference changes, the characteristics of the stem water status were derived: stem water deficit (ΔW) and maximum daily shrinkage (MDS) of stem. The measured data were processed for the period from 1 April to 31 October 2017, 2018, 2019 and 2020. The work evaluates climatic factors such as global radiation, air temperature, precipitation, relative humidity, but also soil water potential, which directly affect the growth and tree water status during the growing season. In terms of the size of the increase, the years 2017 and 2020 were more favourable compared to 2018 and 2019. The diameter increment increased in proportion to the rising air temperature, but only if the stem had a sufficient of water storage. If the stem did not have enough water, the stem shrank and growth stagnated. This phenomenon was more evident for the Norway spruce, which achieved a lower seasonal increase in all monitored years compared to Silver fir. The characteristics of MDS correlated most with atmospheric characteristics, especially global radiation, air temperature and vapour pressure deficit. The stem water deficit was more sensitive to the influence of the values of the soil water potential.