Principles of selecting reference soils for the Red Data Book of Russian Soils

The meaning of the term "etalon" (reference, standard) in natural sciences and, particularly, in soil science is discussed. The need to preserve natural landscapes and soils as reference objects for comparison with their anthropogenically transformed analogues and as a basis for sustaining the natural diversity of plants and animals is demonstrated. The principles and criteria for the choice of reference soils for the Red Data Book of Russian Soils are suggested. The choice of reference soils should be made with due account for the provinces of the soil-geographical (or soil-ecological) zonation as territories characterized by similar environmental conditions and typical soil cover patterns. DOI: 10.1134/S1064229306040016