The effects of climate change on forest ecosystems are more visible. Sometimes they have a positive effect and sometimes a negative one. In order to know how forests respond best, we need to know the patterns of their growth on a wider geographical scale. For this reason, the productivity of white fir and spruce in the Carpathians (Poľana, Low Tatras and northern Romania) was analyzed. For this purpose, we selected 104 individuals (live; without damage). We determined the thickness and height of the trees. We analyzed this data using the Michael function in KORfit. From the analyzed data, we found that the productivity of white fir and norway spruce was highest in northern Romania, slightly lower in Poľana and lowest in the Low Tatras. In two localities (Poľana and northern Romania), spruce had higher productivity than fir.