Syntaxonomic diversity of pasture ecosystems vegetation in south-east Ukraine

This work presents research data on pasture ecosystems vegetation in south-east Ukraine. This survey was carried out during 1998–2011 by route and semi-permanent methods. All botanical and geographical chorions of lower level within the territory of our region were explored. The representation of vegetation formations and associations were studied in following pasture steppe ecosystems: watershed ecosystems with differentiated black soil (43 formations, 425 associations), ravine-gully ecosystems with eroded black soil (81 formations, 750 associations), ravine-gully ecosystems with eroded to granite black soil (48 formations, 293 associations), ravine-gully ecosystems with eroded to limestone black soil (39 formations, 355 associations), above flood-plain terraced ecosystems with cretaceous soil (46 formations, 220 associations), above flood-plain terraced sandy ecosystems (24 formations, 140 associations). It is shown that syntaxonomic diversity of natural pasture ecosystems vegetation is dominantly represented by 1029 associations and 178 formations (37% and 33% from associations and formations of regional native vegetation). As far as steppe ecosystems are concerned, 920 associations and 147 formations are registered (33% and 27% from associations and formations of regional native vegetation). As for meadow ecosystems, we registered 424 associations and 80 formations (15% and 14% from native associations and formations, respectively). The highest syntaxonomic diversity is characteristic of ravine-gully ecosystems on eroded to loess black soil, the lowest diversity of all the steppe ecosystems is reported for above flood-plain terraced sandy steppes. Among meadows, vegetation of salt and marsh meadows has the lowest diversity.