Podzols of the North Sakhalin Lowland under larch forests and dwarf pine: spatial variation of morphological features and properties

The profiles and spatial variation of morphological features, ash content, humus content, pHKCl, granulometric composition, hygroscopic and field moisture in the illuvial-ferruginous and coarse-humus podzols of the North Sakhalin Lowland on sandy soil-forming rocks under specific communities – sparse larch (Larix dahurica) dwarf pine (Pinus pumila), were studied. Statistical characteristics of the variation of indicators for horizons: litter O, coarse humus Oao, podzolic E, illuvial-ferruginous BF, illuvial-humus-ferruginous BHF, transitional BCf, soil-forming rock C, were obtained. It was revealed that the podzolic horizon E has a low thickness, varying from 3 to 11 cm, and its inherent morphological features: whitish color, layered weakly expressed structure, loamy sand and sandy granulometric composition, and a lingual lower border. The horizon BF1 of illuvial-ferruginous podzols is characterized by a rusty brown color, the presence of small Fe–Mn nodules, a humus content of less than 2%, a medium acid reaction, whereas the horizon BHF of coarse-humus podzols has a dark brown color, a humus content of 2–5%, a strongly acidic reaction. Based on the correlation analysis, it was noted that with an increase in the thickness and ash content of the organogenic horizons O, Oao, the humus content increases and the reaction in the illuvial horizons BF1, BHF is acidified. A more acidic reaction of the medium in the O and Oao horizons correlates with an increase in the thickness of the E horizon.