Productivity of restored grasslandsteppe ecosystems
Restoration of grasslands became important in the Central Stavropol region in the middle of the last century. The reason was an increased anthropogenic effect: plowing, industrial and civil engineering, cattle grazing and erosion. Experiments on turf introduction got started at the Stavropol Botanical Garden in 1963 to preserve and restore the unique natural steppe area with a large number of valuable and rare species. Fragments of steppe were grown on 2 ha area from 1963 to 1984. The investigation focused on ecosystem conditions, species composition, botanical groups and yield. Natural steppes performed as controls (Buchinka, Strizhament, Novomaryevskaya Polyana) having similar dominant species as the trial areas. Control areas contained 65-92 species, the restored ones - 83-103. There were 44-72 different grass species grown. Proportions of gramineous averaged to 31.94-46.17%, grass mixtures - 29.40-41.64%, grassland litter - 7.61-28.64%. Contents of legumes varied within 0.85-11.01%, sedge - 0.1-13.83%. Grass productivity of the restored area was high - 3.24-3.97 t ha<sup>-1</sup>. It exceeded the one of the natural areas by 0.61-1.65 t ha<sup>-1</sup>.