Forms of iron compounds in soils of selga landscape on the Karelian Isthmus

The synthesis of different thermodynamically unstable iron hydroxides takes place in soils of selga landscapes on the Karelian Isthmus. Brown forest a nd podzolic types of soil formation differ in the absolute content of noncr ystalline oxalate-soluble iron compounds (Fe-o), their share in the total i ron amount (Fe-o/Fe-t), and reducing capacity (RC). These parameters are mu ch higher in the soils of the brown forest type as compared to those of the podzolic type. The iron compounds are crystallized slower in brown forest soil, which may result from the influence of aggressive organic compounds a nd aluminum (actively hindering crystallization processes).