Scientific Journal of KubSAU

The article considers the regularities of the growth and development of the plantations of Crimean and Scotch pine on sandy soils of Tersko-Kumskoye interfluve plain, presents the classification of forest suitability, estimates the forest growing efficiency and prospects of the use of pine species when forest amelioration of soils, suggests the technologies for forestations arrangement. During the past century there had been grown over 60 hectares of pine cultures on sands of Tersko-Kumskoye interfluve plain under the strict conditions of transition zone dry steppe-semidesert. The Achikulakskaya NILOS VNIALMI (N. K. Lalymenko, V. I. Kabalaliyev, N. S. Zyuz) managed to plant about 60 hectares of Crimean pine and over 5 hectares of Scotch pine cultures in the 70-80-th of the last century, about 50 % of them are still growing. The study of the said forestations led to the following conclusions. On the thick sands (6-8 m) of Bazhigansky forest area the stable growth of Scotch pine continues up to 25-30 years, that of Crimean pine – up to 30-35 years. By the age of 40 the productivity of Crimean pine forestations (170-260 m3/ha) exceeds visibly the accumulated reserve of Scotch pine forest stand (60-100 m3/ha). The increment in height decreases sharply starting at the age of 15-20 years for Scotch pine and at 25-30 for Crimean pine plantations. On the clay sands with the level of low-mineralized ground water of 2,5-3,0 m and despite high fall the stable growth of Crimean pine continues up to 35-40 years and more. On the monophase sands of Tersky forest area the Crimean pine grows relatively slowly during the first 10-15 years though more evenly year by year. The thick lamellar deposits and monophase sands with the depth of sweet ground water of 3-5 m provide the best conditions for forest growing. The longevity of Scotch pine plantations of 50-55 years and that of Crimean pine of 60-65 years can be achieved by current planting technologies and effective conservation of the forestations on the thick sands, while on the medium thick clay sands it can be 60-65 and 70-75 correspondingly, and on the monophase sands on the sites with the additional life-long sweet ground water nutrition – over 80 years. The following measures should be the most effective when afforestation of highly overgrown sites – the many-year fallow and thorough cultivation of inter-rows of young cultures and their planting with coulisses and blocks. When planting of cultures on interfluve plain on lightly overgrown sands of low water capacity the planting of seedlings by combined aggregates type MPP-1 provides the best results. The ecological and economical effectiveness of forest amelioration of pastures forms of the costs of the woody and non-woody forestation resources, their soil-conservation, environment improvement and recreation functions. The effect of one hectare of pasture protective pine coulisses planted on lowdegraded pastures should be about 35 thousand rubles during 50 years (average longevity of forestations), when amelioration of highly overgrazed pastures it would be 130 thousand rubles per year. The main part (80-90 %) of the benefit takes the costs of the prevented loss caused by wind erosion