Soils of larch forests in «Spasskaya pad» and «Elgeeii» stations (Central Yakutia)

Abstract

Specificity of features and characteristics of soils from two forest international ecological monitoring network stations located within the Central Yakutia plain were studied. The studied areas differ in moisture and genesis of parent materials. The Spasskaya Pad station is located in the area with a moderately warm, arid climate with a sum of active temperatures of 1400–1500 °C and a humidification module <0.20 according to D.I. Shashko. The Elgeeii station is located in the area with the moderately warm but slightly arid climate with the humidification module of 0.20–0.30. The parent materials of the Spasskaya Pad station are represented by sandy-loamy carbonate deposits. Whereas in the Elgeeii station, the eluvial-deluvial loamy carbonate deposits on bedrock play a role of the parent material. It has been revealed that under the low-productive larch forests (bonitet V–Va) of the Spasskaya Pad station permafrost sod-pale solodic coarsehumused soils with a structure of a profile O-AYaoe-BPLhi-BPLcr-BCAg,cr are dominant. The sod-pale typical soils with the profile O1/O3-AY-BPL-BCA-BCca have developed under the medium-productive larch forests (bonitet III–IV) of the Elgeeii station. Differences in composition of granulometric fractions and absorbed bases as well as some parameters of a humus state of the soils were revealed. The present studies confirm a previously proposed need to identify a type of sod-pale soils in the Classification of Soils of Russia, which are characterized by pH values in a weakly acidic range in upper horizons and alkaline in the lower horizons; a low humus content in the mineral horizons and a high proportion of weakly decomposed organic matter in the organogenic ones, with a sequence of the horizons: AY-BPL-BCA-Cca.