Ecosystem carbon storage distribution between plant and soil in different forest types in Northeastern China

Plant and soil carbon pools are two important elements of forest ecosystems and both are affected by many environmental factors. Although forest types are typically characterized using species composition, the ways in which soil carbon storage (CS) is distributed between plants and soil in different forest types and the factors influencing this distribution remain unclear. In this study, we calculated CS in plants and soil by sampling 108 tree plots and 324 soil profiles to determine whether plant and soil CS varied significantly among different forest types in this region. Boosted regression tree analysis was used to detect factors influencing forest CS allocation. The results showed that plant CS varied from 68.09 t ha−1 in aspen-white birch forests (AW) to 117.81 t ha−1 in mixed Korean pine-broadleaved hardwood forests (KB). Conversely, soil CS varied from 153.23 t ha−1 in KB to 261.58 t ha−1 in AW. Forest management was the main factor influencing plant CS while soil CS was most influenced by factors relevant to moisture. The influence on the ratio of plant CS to soil CS was quite complex because the dynamics of the relationship were affected by managerial, climatic, and topographical factors. In addition to species composition, ecosystem CS also varied in different forest types and was influenced by complex factors related to climate, topography, and forest management.