Examination of the organic carbon stock of the soil of Hungarian beech stands and the determining factors

The beech stands ratio of Hungarian forests barely reaches 6%. However, beech is a native tree species with high production capacity; therefore, its importance in nature conservation and economy is significant. Due to global climate change, the focus is on the ability of carbon fixing and storage capacity in beech forest ecosystems. While we can estimate the amount of biomass above ground with relative precision, we have little data about organic carbon in soils.

The primary goal of our work was to collect as much data as possible on the amount of organic carbon stored in the soil of these native forest stands. Furthermore, the most significant factors were determined that influenced the sequestration.

During the research, undisturbed and disturbed soil samples were collected from every 10 cm layer in 40 beech stands. The depth depended on the bedrock. On loessy or sandy bedrock, the depth was 110 cm. In the case of rocky structure, samples were taken from 0-40 cm depth. Moreover, litter samples were taken and analyzed. The properties of the stands were also recorded on the sampling sites (tree species, diameter, etc.).

The soil pH was 5.17 on average, while the minimum value was 3.87 and the maximum was 8.4. The humus content varied between 0.16 and 15.65% because it decreased with depth. The average organic carbon stock was 6.39 C t/ha (Cminimum  1.46 C t/ha, Cmaximum 34.03 C t/ha). Moisture determines the organic carbon stock of the soil most of all.

This article was made in the frame of the project TKP2021-NKTA-43 which has been implemented with the support provided by the Ministry of Innovation and Technology of Hungary (successor: Ministry of Culture and Innovation of Hungary) from the National Research, Development and Innovation Fund, financed under the TKP2021-NKTA funding scheme. Some of the tools used during the research were acquired within the framework of the "Investigation of the conditions for the cultivation of wood biomass - GINOP-2.3.3-15-2016-00039" project.