At present, in connection with the expected climate change, increasing emphasis is being placed on the issue of monitoring the occurrence of precipitation extremes as well as changes in the temperature regime and their impacts on forest ecosystems. It is very likely that in changing climatic conditions, forest ecosystems will be increasingly disturbed and will provide ecosystem services at a level below their natural potential. The thesis focuses on the growth response of two tree species with different environmental requirements and sensitivity to drought and climate extremes. The aim is to evaluate the behaviour of these tree species outside their ecological and growth optimum. From the circumferential dendrometer records, it is possible to obtain with high accuracy stem circumference changes of selected species of conifers (Larix decidua and Pinus sylvestris) grown in the same locality characterized by warmer and drier conditions than their natural habitats. Climatic factors such as precipitation, relative humidity, air temperature and global radiation affect the stem circumference changes of the monitored forest tree species . When they deviate from the long-term average, this has a negative effect on tree species, which subsequently do not achieve optimal growth and development. It is clear from the results that in all monitored periods, European larch grows less than Scots pine.