ORGANIC CARBON CONTENT IN THE OLD-ARABLE SOILS OF THE UKRAINIAN POLISSIA FOREST ECOSYSTEMS

Summary The results of studies on the content of organic carbon in the block “phytodetrite - soil” of forest ecosystems in Zhytomyr and Chernihiv Polissia are presented in the paper. It is shown that under the conditions of water irrigation regime and predominance of coniferous vegetation the process of humus accumulation in old-arable sod-podzolic soils of automorphic type due to their sand granulometry (average particle content <0.01 mm - 6.8 %) is characterized by low intensity. The thickness of the profile humus portion is 18 ± 1.3 cm, the humus distribution is sharply falling with the depth - from 1.4% in He-horizon to 0.19 in Ph horizon. The carbon content in the automorphic soils is on average 0.74%, its stocks are 33.9 t / ha and in hydromorphic organogenic soils it increases to 18.1% and 168.9 t / ha, respectively. It is determined that the carbon content in the pine forest litter is quite stable and equals to 40 ± 1.4%, while its stocks range within 30–33 t / ha.