Bioproductivity of pine forests in Polissia

The purpose of this study was to determine the bioproductivity of pine forests in Polissia and their carbon sequestration capacity depending on the age structure of the stands. The study was conducted at 15 experimental sites in the Zhytomyr and Rivne regions during the spring and summer season of 2023. Tree biometrics such as diameter at breast height (DBH) and tree height were measured, and wood samples were analysed to determine the phytomass of the trunk, bark, and crown. It was found that bioproductivity increased significantly with age: in young forests (10-30 years old), biomass averaged 25 t/ha, in middle-aged forests (40-60 years old) – 65 t/ha, while in mature forests (80-100 years old) it reached 120 t/ha. The correlation analysis showed a pronounced dependence of biomass on tree diameter and height, with the strongest relationship between trunk volume and wood phytomass (r=1.00). The carbon-absorbing capacity of forests also increased with age: young forests absorbed about 12.5 t/ha of carbon, middle-aged forests – 32.5 t/ha, while mature forests – up to 60 t/ha. Furthermore, the study found that climatic factors such as rainfall and average temperature substantially affect bioproductivity. When precipitation fell below 550 mm per year, a 15-20% decrease in biomass was observed. Thus, the findings emphasised the significance of sustainable management of pine forests in Polissia, considering their role in global carbon sequestration processes, making them a valuable tool for combating climate change and environmental challenges