Ninth International Conference on Permafrost ... - IARC Research

Development of Soil Databases on the Territory of Permafrost-Affected Regionsin RussiaD.I. Rukhovich, N.I. Belousova, P.V. Koroleva, E.V. Vil’chevskaya, L.G. KolesnikovaV.V. Dokuchaev Soil Science Institute, Russian Academy of Agricultural Sciences, Moscow, RussiaSoil mapping in Russia has a rich and long history. Sincethe time of Dokuchaev, a system of soil maps of the countryon different scales has been developed. The soil mapsin Russia are compiled on very different scales: from the1:10,000 scale for separate farms to small-scale maps (1:16M) included in the national atlases.Soil maps on the scale of 1:1 M and smaller are availablefor the whole territory of Russia. The 1:1 M state soil mapis currently at the stage of its finalization and updating.Both the legends to separate pages of the map and the soilpolygons are being updated. Soil maps on the scale of 1:4M and smaller give the general picture of soil distributionin the country. The number of soil polygons on such mapsis relatively small; these maps do not correlate well withthe topographic bases and the materials of remote sensing(satellite imagery). The 1:2.5 M map occupies a transitionalposition in this series of soil maps of Russia. There are35,000 soil polygons on this map and 305 mapping unitsin the legend, including 205 soil units and 100 names ofdifferent soil combinations (soil complexes).Traditionally, soil maps for the territory of Russia arepublished with legends and special explanatory notes.However, these valuable reference materials usually donot contain quantitative information on the soil properties.A thorough study of soil classification systems appliedon the maps of different years makes it possible to judgethe geographic distribution of soils, but does not allowquantitative calculations and the development of specialmaps, for example, the maps of soil acidity or the mapsof carbon reserves. The absence of quantitative soilcharacteristics lowers the efficiency of digital versions ofsoil maps on the territory of Russia. The creation of thegeographic information system on Russian soils suppliedwith necessary attribute databases on the soil properties isone of the challenges for soil geography in Russia.The soil databases have to include information on thesoil profile horizonation and characteristic depths of soilhorizons. Thus, podzolic soils are characterized by thefollowing horizonation: O-A2-A2/Bt-Bt-BtC-C. The Ohorizon O is thin (5–10 cm), slightly decomposed leaflitter; the eluvial horizon A2 is a light-textured horizon withplaty structure and very variable (5–50 cm) thickness. Thetransitional eluvial-illuvial whitish/brown horizon A2/Btturns into the dark-brown or brown illuvial horizon Bt of35–55 cm in thickness. The Bt horizon has a heavier texturethan the A2 A2/Bt horizons and clear illuviation featuresin the form of clay coatings. It gradually turns via the BtChorizon into the parent rock C at a depth of 300–350 cm.Quantitative characteristics of the soil properties should begiven for every genetic horizon. At present, it is feasibleto perform this work on the basis of the “Soil Map of theFigure 1. “Soil Map of the Russian Federation,” 1:2.5 M scale.Figure 2. Agroclimatic zoning of Russia.Russian Federation” on the 1:2.5 M scale (Fridland et. al.1988, Fig. 1).The unified legend to this map is supplied with informationon the horizonation of 205 soil units shown on the map.The legend to the map also contains information on the soiltexture and on the character of parent materials. The texturalpart of the legend consists of 30 units. A given soil unit can befound on parent materials of different geneses and textures.On average, there are three texture classes corresponding tothe given soil units. A combination “soil name + texture”gives us about 600 different soils shown on the map. Thesame genetic unit of soil developed from the parent materialsof different textures normally has different quantitativecharacteristics of its properties, including the thickness ofsoil horizons, the humus content, base saturation, etc.Each of the 600 combinations “genetic soil name + soiltexture” has its own spatial distribution. Its properties varyin dependence on the particular climatic and geobotanicconditions. The character of climatic conditions can hejudged from the special map of climatic zoning of Russia.259