Differentiation of the Material Composition of Lviv Region Luvic Greyzemic Chernozems (Ukraine)

The soil formation within the Wet Atlantic Chernozem facies of the West-Ukrainian region leads to the vertical redistribution of Chernozem soil substance and formation of the differentiated mineral soil profile to varying degrees by carbonates, clay, and chemic-mineralogical composition. Luvic Greyzemic Chernozems (Siltic, Aric, Pachic) is characterized by the sharp differentiated profile by clay. The degree of vertical differentiation of clay profile is directly proportional to the intensity of the processes of leaching and gleyzation. In mineral profiles of Luvic Greyzemic Chernozems the vertical redistribution of clay material is mainly due to fraction smaller than 0.02 μm. The opposite character of profile distribution of mica-smectite and illite phases of clay minerals was discovered. Against the unbalanced losses of a part of clay plasma in the humus horizon, the process of relative illitization was detected due to smectite eluviation and accumulation of illite, kaolinite and finely dispersed quartz.

ҐРУНТОВО-ГЕОГРАФІЧНЕ РАЙОНУВАННЯ ШИРОКОЛИСТЯНО-ЛІСОВОЇ ҐРУНТОВО-БІОКЛІМАТИЧНОЇ ЗОНИ УКРАЇНИ

The soil-bioclimatic zone of broad-leaved forests extends to the west and south-west of the forest-steppe zone and is timed to the most elevated and dissected regions of the Volyn’ and Podillia uplands, as well as the Glukhiv plain of the Serednjorus’ka Plateau. This zone was considered as a kind of forest-steppe island (Volyn’ Highland), or as a continuation of the forest-steppe zone in the west and north-east of Ukraine. On the map of agro-soil zonation of Ukraine, this territory belongs to the forest-steppe zone, soil-geographical zonation – to the broad-leaved forest and forest-steppe zones. The zone of broad-leaved forests is highlighted on the map of geobotanical (1978) and physical-geographical (2003) zonation of Ukraine. The zonation of this territory did not take into account the features of the soil structure, the morphological features of the soils, the nature of their role in soil combinations, and the history of nature development in the Holocene. In our opinion, the geobotanical zonation of 1978 is the closest one to the soil-geographical zonation.The purpose of soil-geographical zonation is to identify the relationship of soil cover with environmental conditions and the allocation of territories with the same structure of soil cover, a combination of factors of soil formation and the possibility of economic use of soils. The main approach to soil-geographical zonation was a structural approach that evaluates the structural difference between different regional units of soil cover.The central taxonomic unit of soil-geographical zonation is the Soil’s Krai. The Soil’s Krais are characterized by a natural combination of several genetic types of relief and are an association of the corresponding forms of soil structures, which are dominated by certain classes of soil combinations.The scheme of soil-geographical zonation reflects the spread of taxonomic units of soil, rather than systematic units of soil (types, subtypes).In the zone of deciduous forests mutually penetrate into each other, often forming mixed habitats, different types of forests with domination of beech, hornbeam or oak. In the structure of forest-meadow landscapes, in particular, at the margins or valleys, so-called forest-steppe areals with regraded chernozems, and eroded soils are widely used. Alpine, meadow and marsh soils are common in the river valleys, wide and narrow beams, on the floodplain terraces, forming the lower tiers of soil mezocombinations.In the broad-leaved zone of high-ordered erosion-tree-like combinations and combinations of variations of podzolization and gleying, we distinguish five Soil’s Kraiy (Volynskyi, Roztotsko-Opilskiy, Tovtrovyi, Central Podilskiy, Serednjorus’kiy) and 23 Soil’s Okrugy.The presented scheme of soil-geographical zonation is an author’s variant and needs improvement and refinement by conducting large-scale field studies of soil structures.Запропонована нова схема ґрунтово-географічного районування широколистяно-лісової ґрунтово-біокліматичної зони України до рангу краю і округу. Вона ґрунтується на принципах структурного підходу до просторової організації ґрунтового покриву. Критерієм виокремлення районізованих одиниць різного рангу, їхньої просторово-генетичної характеристики, є якісно-генетичні показники ґрунтового покриву з аналізом просторового розміщення ґрунтових комбінацій і ґрунтових структур. У межах широколистяно-лісової ґрунтово-біокліматичної зони України виділено 5 ґрунтових країв і 23 округи