The impact of the Botanical Garden of Oles Honchar Dnipro National University reconstruction on the soil aggregate structure

Abstract

The reconstruction factor can significantly affect changes in soil cover. Physical soil properties changes are one of the main reasons for some plant species disappearance and the existing communities disintegration. The variation of soil aggregate structure in the areas affected by the reconstruction and in the areas without such within the Botanical Garden of Oles Honchar Dnipro National University has been studied. It is established that on all sample polygons there is a predominance of content of microfractions (less than 0.25 mm in size). But in the polygons affected by reconstruction, the proportion of microfractions is markedly higher compared to polygons without reconstruction. The sample polygon a, on which the reconstruction was carried out, differs significantly from the others in the lowest content of macrofractions, as well as mesoaggregates of size 7–10, 5–7 and 3–5 mm. At the same time, the highest content of fractions of 1–2, 0.5–1 and 0.25–0.5 mm is observed in this polygon. On polygons that were not affected by reconstruction (polygons c and d), there is a predominance of mesoaggregates 2–3 and 3–5 mm compared to polygons that were reconstructed (polygons a and b). The discriminant analysis made it possible to differentiate the polygons by the aggregate structure pacularities. By the peculiarities of the aggregate structure, the canonical root 1 separates polygon a from all other polygons, and the canonical root 2 opposes polygon b to polygons c and d. Root 1 correlates with the content of aggregates from 3 to 10 mm in size, while root 2 correlates with the content of micro-aggregates and aggregates from 0.25 to 0.5 mm in size. The influence of the reconstruction of the Botanical Garden of Oles Honchar Dnipro National University noticeably affected the aggregate structure of the soil reconstructed polygons, leading to a marked increase in microaggregates and a corresponding decrease in mesoaggregates, favorable for the growth of phytocenosis.