ON THE PROBLEMS OF ZONE DIVISION OF ARID TERRITORY OF THE EUROPEAN PART OF RUSSIA
In the south of the European part of Russia, two arid zones are distinguished: steppe and desert ones. Inclusion of a semi-desert zone in the spectrum of natural zones became traditional, despite uncertainty of its substance. We follow E. M. Lavrenko and consider a belt with light chestnut soils («northern semi-desert») as a southern subzone of the steppe zone, that with brown soils («southern semi-desert ») as a northern subzone of the desert zone. On the light chestnut loamy non-salinized soils, steppe (Stipa and Artemisia) communities are always formed, while on the brown soils - desert coenoses where Stipa spp. never dominate. Moscow soil scientists, unlike their Kazakhstan colleagues, classify both light chestnut (steppe) and brown (deserted) as semi-desert ones, and this has led to «disappearance» of the desert zone in the southern European Russia. Strong anthropogenous press (abandoned fields, haymaking, overgrazing) humpers interpretation of zonal position of some areas, since abandoned fields in the steppe zone are the places of growing wormwoods which give «deserted» aspect to the landscapes, while in the desert zone, under the effect of haymaking and overgrazing the wormwoods may disappear and grasses thrive, and create «steppe» aspect.