Grey forest soils in the different classification systems

Abstract

According to various data, the area of grey forest soils in the world is 94–120.2 million ha, in Ukraine – 4.7–5.5 million ha (about 9 % of the country’s territory). The diversity of conditions for the formation of these soils, discussions about their genesis are the causes of different approaches to the classification of grey forest soils. The history of the classification of grey forest soils is analysed; the most common variants of their classification in Ukraine are presented. Seeking to find approximate equivalents, an attempt to find grey forest soils in the classification systems of different countries (Russia, Moldova, Bulgaria, Romania, Czech Republic, Poland, USA, Canada), as well as in the legend of the FAO-UNESCO map and the WRB has been made. To establish exact analogues of soils practically it is impossible due to different principles of classification’s construction. Modern soil classifications of different countries are as close as possible to WRB and “Soil Taxonomy”. The following names of grey forest soils are identified as the most grounded: light grey forest, grey forest and dark grey podzolic. The following equivalents of the WRB nomenclature (2014) for sub-types of grey forest soils are offered: light grey forest – Albic Luvisols, grey forest – Haplic Luvisols, dark grey podzolic – Luvic Greyzemic Phaeozems. To the names of analogues of these soils with gleyic properties, the qualifier “Gleyic” should be added before the name of the reference soil group. The urgent task for soil scientists of Ukraine is to create a new soil classification that would preserve the acquisitions of genetic soil science but took into account the world trends: the allocation of diagnostic horizons and features that have clearly defined quantitative boundaries. In the new classification, it is proposed to combine the light grey and grey forest soils by a separate group, dark grey podzolic soils to be grouped together in a group with podzolic chernozems. The need for such selection is confirmed by the study of the dark grey soils position in different classification systems of the world, most of which these soils are in the chernozemic type group (Mollisols, Phaeozems and Chernozems). Key words: classification, grey forest soils, Greyzems, Luvisols, Mollisols, Phaeozems.