Unaccounted Factors Determining Carbon Stocks in Forest Soils

The sources of uncertainties in estimating soil carbon stocks in forest ecosystems, including abiotic (mechanical composition of soil) and biotic (plants, earthworms) factors, are discussed. The results of comparative assessment of soil carbon storage in coniferous-broadleaved and taiga forests based on direct measurements and pedotransfer functions are presented. It is shown that the estimation of soil carbon stocks in forests based on both direct measurements and pedotransfer functions requires, along with other soil formation factors, taking into account the most dynamic ones, including plants and soil biota, as well as the history of nature management. The calculation of soil carbon stocks should be carried out with account of fine earth ( < 2 mm fraction) content.