Conventional and digital soil mapping in the central part of the Smolenskoe Poozerye National Park

For an area of 8.6 km2 in the central part of the Smolenskoye Poozerye National Park, soil maps (1 : 25 000) were made using conventional and digital mapping (DSM) methods based on relief, vegetation, time and antropogenic factors of soil formation with subsequent comparative analysis of the results. Both maps show that the study area is dominated by gray humus soils (Umbric Cambisols (Arenic, Aric)), which are related to agricultural land-use in the past and self-restoration of abandoned plowed soils. Smaller territories are occupied by alluvial peat (Histic Fluvisols) and postagrogenic texture-differentiated soils (Albic Glossic Retisols (Aric, Loamic)). The overall accuracy of the map made by the DSM method was 57%. The Topographical Wetness Index (TWI) and the forest taxation map were leading soil-forming factors, represented in both expert and digital models. The distribution of alluvial peat (Histic Fluvisols) and agrozems (Arenosols (Aric)) is best predicted by DSM method (with an accuracy of 100 and 86%, respectively) and associated with peat deposits and modern arable lands. The location of peat soils (Fibric Histosols) and peat-podzols (Histic Albic Podzols (Arenic)) is predicted with the least accuracy (0%). The accuracy of predicting the location of Al-Fe humus (Podzols), texture-differentiated (Retisols), organo-accumulative (Umbric Cambisols), gley (Histic Gleysols), and alluvial humus gley soils (Gleyic Fluvisols) varied within 50–63%. The DSM method reproduced the result of conventional mapping by 63%.