Kurgans help to protect endangered steppe species in the Pontic grass steppe zone, Ukraine

The steppe vegetation has been destroyed to the greater extent than any other type of zonal vegetation in Europe. Ancient mounds (barrows, kurgans, tumulus) persisted in the large-scale, intensively cultivated land and constitute the isolated micro-hot spots of steppe biodiversity. In the present paper floristic value of 26 kurgans among 120 visited in the West Pontic grass steppe zone was assessed and compared to the flora of steppe reserves ('Askania-Nova', Takovlivskyi', Lesovyi Canyon') located within the zone. Particular attention was paid to the richness and structure of the flora (proportions of: steppe species, species of special concern, alien weeds).The relationships between the flora of kurgans and the reserves, based on the total species diversity were analyzed using indirect ordination techniques (PCA). The flora of the investigated reserves was typical of the West Pontic grass steppe zone but differed with regards to the local habitat conditions. The flora of kurgans is representative of the zone to a similar extent as the flora of reserves located on the loess substratum. Kurgans contribute to the conservation of valuable steppe species outside legally protected steppe areas. Therefore, in the places where they are abundant, they could play an important role in the future restitution of the European and Eurasian steppes.