Carbon stocks in phytomass and biological productivity of mature and overmature forest stands in Suburban Forestry of Voronezh Region

Forest-steppe ecosystems, representing an ecotone between forests and steppes, are particularly vulnerable to climate change. The observed trends of temperature increase and precipitation decrease in the southern European part of Russia affect the productivity of natural ecosystems, transforming their carbon balance. This may have implications for the sustainable functioning of forest-steppe ecosystems and biodiversity conservation. Assessment of carbon stocks and fluxes in forest ecosystems is crucial for understanding their role in climate change mitigation. A comprehensive study of carbon stocks and biological productivity of mature and over-mature forest stands in the Suburban Forestry of the Voronezh region has been conducted. It was found that the maximum carbon stocks in phytomass are characteristic of both coniferous stands (up to 133 tC/ha) in pine forest landscapes and mixed deciduous stands in upland oak forests (up to 141 tC/ha). Patterns of carbon distribution across phytomass components in tree stands of various species composition have been identified. The biological productivity of the studied tree stands was found to vary depending on forest growing conditions and species composition. The highest values of annual carbon increment in phytomass were observed in mixed stands dominated by Quercus robur L. (up to 2.60 tC/ha per year). The obtained results can serve as a scientific basis for developing regional programs to optimize the carbon balance of forest ecosystems and improve methods for assessing their ecological functions.