Seasonal dynamics of lawn coverages of Nikopol city (Dnepropetrovsk area)

Abstract

The features of the seasonal dynamics of the species composition, the total projective cover, the ecomorphic structure and the decorative score of the lawn coverings of the city of Nikopol are studied. It was revealed that during the growing season, representatives of the Poaceae family dominate in the projective cover and species composition of grass communities in urban areas. In spring, the participation of Brassicaceae and Lamiaceae is increased, in summer and autumn – Fabaceae and Asteraceae. A study of the dynamics of the species composition showed that Poa angustifolia L. and Polygonum aviculare L. dominate in the majority of Nikopol's lawns in spring. In summer, Lolium perenne L. and Ambrosia artemisiifolia L. are added to them. In autumn, the most active are Lolium perenne and Poa pratensis L. Analysis of the seasonal dynamics of the total projective coverage of test areas showed that the average values ​​of this indicator are observed at the beginning of the growing season. In summer, the total area of ​​the green parts of the plants is reduced. At the end of the growing season, due to the increase in productive soil moisture, the photosynthetically active plant area increases significantly in areas with low anthropogenic impact, remains at summer levels in places of medium anthropogenic loading and significantly decreases in areas with high anthropogenic load. In the species composition, throughout the entire growing season in the biomorph spectrum, hemicryptophytes are the most active, among ecomorphs are xeromesophytes, mesotrophs, ruderants and stepants. Decorativeness is quite low, on a five-point scale, ranges from 2.23 to 3.49, due to the presence of weeds and high anthropogenic stress. In order to improve the decorative, phytomeliorative and hygienic properties of the grass cover, it is advisable to recommend systematic grass cutting (to reduce the activity of annual weeds), as well as the spread of perennial forest and meadow species.