Abstract
Despite the fact that forests in nature conservation areas are of mature and over-mature age, they have a leading role in the production of ecosystem services, in particular in ensuring biodiversity. In the typical sense, at the mature and over-mature age of stands, the growth of live biomass and carbon sequestration almost stops, and the death of trees leads to a negative change in the stock. The purpose of the study is to substantiate the ability of over-mature forests to accumulate live biomass under the condition of the formation of multi-tiered and different-age stands. The research was conducted on four permanent sample plots of the Feofania park-monument, which were established in 2016 and 2017. The method of approximate mensuration was used to study the current growth of ecosystem services. The method of dendrochronology was used to analyse annual rings. The age range of experimental stands is between 80 and 180 years. Experimental stands of all sample plots are characterized by high-level productivity, compared to model data on the productivity of stands in Ukraine and the European part of Eurasia. According to the results of the research, it was established that the biggest current increment of ecosystem services is formed in the uneven-aged stand with the centuries-old common oak trees of the overstory. The results of the research can be used in practice for the management of nature conservation areas and improvement of the management of over-mature forests