Associations between forest vegetation and the fertility of soil organic horizons in northwestern Russia

Background Being the product of the same environment, soil and vegetation are mutually associated with each other, but the relationships between edaphic properties and vegetation characteristics are still far from clear. Accordingly, the specific aim of this study is to identify relationships between forest site types/forest types and the fertility of soil organic horizons in northwestern Russia. The relationships were assessed at the level of three large forest regions, the northern and middle taiga of the Republic of Karelia, and the Karelian Isthmus (Leningrad region), based on 37 spruce, 66 pine, and 16 birch plots which were integrated with the International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests).