EN
The paper presents the floristic changes in species composition of meadow sward after five years when the meadows were desisted from management (cutting). The meadows are situated on hydrogenic soils in proglacial stream Valley of Vistula River and they belong to landscape reservation "Ursynów Slope". In 1998 before the first cut vegetation patches were separated according to floristic aspects. Then samples of vegetation (from 1 m² ) were taken from cach patch; number of samples depended on floristic diversity and ranged from 1 to 4. Floristic types were determined basing on the dominant species with the share above 30% of mass. In 2003 the samples of vegetation were taken from the same places and using the same methods like in 1998. The floristic changes in species composition of meadow sward after desistance from management for five years resulted in: decrcasing in the total number of species - from 78 (1998) to 66 (2003); disappeared mainly the species from dicotyledons (8 species), among them very low species and ephemeral weeds, decrcasing in the number of floristic types - from 16 (1998) to 9 (2003), increasing in the sward of poor quality grasses such as Deschampsia caespitosa and Holcus lanatus. Those species became dominant in three of floristic types and their share exceeds more than 30% in the majority of meadow sward, increasing in the share of high grass species and decreasing in the share of low grass species, the great increase in the share of sedges, rushes and horsetails in 2003, the great decrease in the share of dicotylcdons (weeds and herbs) in cach floristic type, invasion and expansion of weeds of areable lands, later development of trees and shrubs and increasing in the share of forest species in the meadow sward. Preservation of existing biodiversity is possible only in case of introduction of active preservation using extensive form of management.