AGROFORESTAL ACTIONS FOR PRESERVATION OF FERTILITY SOIL THE SOUTH OF AVERAGE SIBERIA AND THEIR RATIONAL USE
A new scheme of sylvicultural reclamation regionalization of the south of Central Siberia is developed. It includes a forest steppe zone with Krasnoyarsk, Tuva and Khakassia sub zones, steppe one with Tuva sub zone and dry steppe one with Tuva and Khakassia sub zones. To select other taxonomic units (districts) is inappropriate, since every features of creation of shelterbelt forest, which are possible at present and are proposed to implement, you can realize in zones and subzones. Priority application should have a drill way of shelterbelt forest creation, which features simplicity and possibility to mechanized soil preparation and plantation care with serially manufactured machines and equipment. In dry steppe and steppe sylvicultural reclamation zones it is reasonable to create single species double row belts with row spacing 6...8 m and tree number up to 1000 units/ha. In a more favourable forest steppe zone you can create 2 3 row in line field protective single species forest belts with row spacing 3 m and tree number up to 1.5...2 thou units/ ha. Introduction of shrubs to field protective forest belts in arid zone on the windward side is impractical, due to the heavy water regime. It is reasonable to create massive protective forest plantations on unsuitable for agriculture land under condition of critical shortage of moisture as belts 50...200 m width, alternating with belts of herbaceous plants. The optimal distance between protective forest belts in the dry steppe zone using Siberian larch is 210...240 m, in the steppe one - 270...300 m, in forest steppe one - 330...360 m. For drooping birch these values are 180...200, 210...240 and 270...300 m, for Siberian elm 150...210, 210...270 and 240...270 m.