ECOTOPIC CHANGES IN THE MEADOW STEPPE OF "MYKHAYLOVSKA TSILYNA" RESERVE UNDER DIFFERENT CONSERVATION REGIMES

Abstract

Using synphytoindication methods and ordination matrices we have demon-strated the differences in ectopic characteristics of protected steppe sites with different conserva-tion regimes (absolute protection and periodic mowing) in "Mykhaylovska Tsilyna" Reserve, Su-my Region, Ukraine. These boreal steppes are extremely unstable under the regime of absolute protection and tend to transform quickly to forb meadows and shrub complexes on the non-mowed ranges. The large parts of the protected steppe is mown in 5 year rotation pattern, resulting in the renewal of previously lost xeromorphic structures dominated by Stipa pennata L., Festuca rupico-la Heuff., Carex humilis Leys., Poa angustifolia L. and other species of the grass stand. With the use of leading ecological factors, we have determined the fundamental differences in the form and overlaping degree of landscape niches, visualized the process of expansion, mesophytization, in-version carbonation, soil nitrogen enrichment, acidity and trophic properties increase and the sub-sequent transition towards the boreal thermozone of the general thermoregime. Basing on the ec-topic analysis results of habitat steppe ranges with different conservation regimes, we can make a conclusion about the necessity of ecosystem management for the conservation of the main charac-teristics of the steppe coenostructures.