The reconstruction impact on the urban ecosystem park plantings on the example of the Oles Gonchar Dnipro National University Botanical Garden

Abstract

The article is devoted to the study of the reconstruction impact on park plantings located in the Oles Honchar Dnipro National University Botanical Garden. The reconstruction of the botanical garden was carried out in 2018 and consisted of the removal of 74 old trees, sanitary pruning of some plantings, and the laying of asphalt paths. To determine the impact of the reconstruction on the greenery of the DNU Botanical Garden, four test plots were laid down: plots a and b in the reconstruction area, plots c and d in the unreconstructed area. The following physical parameters of the soil were measured at the test sites: soil penetration resistance, electrical conductivity and moisture. The research was conducted in April – May 2021. Soil penetration resistance is an informative indicator sensitive to anthropogenic impact, its measurement is fast and allows obtaining significant amounts of information in a short time. Electrical conductivity is related to soil moisture and salt content. These indicators, combined with phytoindication methods, allowed us to draw conclusions about the impact of the reconstruction on the soil and green spaces. The landfills differed significantly after reconstruction in terms of the profile distribution of average soil penetration resistance values. The reconstruction area soil is characterized by the appearance of peak soil penetration resistance values at depths of 35–50 cm and 85–90 cm. Polygons a and b have much higher values of topsoil penetration resistance than polygons c and d. The coefficient of variation of soil penetration resistance profile distribution at the test sites in the reconstruction zone also demonstrates a specific character – it has a pronounced peak at a depth of 25–40 cm and gradually decreases with depth. The conclusion about the reconstruction impact on the soil penetration resistance of the botanical garden soil changes was made based on the results of the General Linear Model, which was estimated by the Radj2 index. The distribution of soil electrical conductivity values has a pronounced bell-shaped character. At all the test sites, there is a tendency for electrical conductivity increasing which is positively correlated with moisture. By means of the phytoindicative scales the hemerobia index was determined, which demonstrated a statistically significant linear relationship (p < 0.001) with soil electrical conductivity.