Syntaxonomy, synphytoindication analysis and anthropogenic transformation of forest vegetation in Kyiv city

Abstract

The aim of this work was to determine the floristic composition, phytocoenotic diversity of woody vegetation, degree of anthropogenic transformation and ecological analysis using the synphytoindication method. The objects of our study were forest communities, forest-parks and green area of Kyiv. In 2015–2015, we fulfilled 323 relevés that were made by the standard procedure. All plant species were recorded. For each relevés geographic coordinates are indicated. The floristic analysis of the woody vegetation of Kyiv was conducted using the Braun-Blanquet approach and the phytosociological table was constructed with non-hierarchical clustering algorithm for vegetation classification so called DRSA («distance-ranked sorting assembling»). Phytoindication method was used for environmental analysis. We assessed amplitudes of syntaxa by phytoindication method for moisture (Hd), acidity (Rc), soil nitrogen content (Nt), total salt regime (Tr), light in community (Lc) and we calculated hemeroby index. Synecological amplitudes are characterized by the values of the minimum, maximum and average values ecofactors of the aggregate description of each community. Systematic, biomorphological, geographical structures were analyzed as well. We used hierarchical agglomeration cluster analysis of syntaxons to estimate the similarity of the species composition of the cenoflor. We identified that woody vegetation is divided into two classes Querco-Fagetea and Robinietea which include 11 communities types of rank association-variant. A total number consist of 169 species 133 genera 59 families. Species of alien origin constituted 20-40% of the cenofloras, which indicate increasing anthropogenic impact. Recreational load is a leading factor in anthropogenic impact. Biomorphological analysis indicates the predominance of herbal perennial plants – hemicryptophytes in the species composition of plants. And we determined that the nitrogen content in soil, acidity and moisture are the environmental factors leading to differentiation of vegetation. For assessment of anthropogenic transformation we used hemeroby index. Main purpose of the hemeroby index is to determine the degree and dynamics of human impact on plant communities. Hemeroby index is ecologically well founded, plausible and easy to interpret. The lowest level is represented in phytocoenoses order Fagetalia, followed by the communities of order Quercetalia and Chelidonio-Robinietalia from class Robinietea. Robinia pseudoacacia + Chaerophyllum temulum communities were most disordered. To determine the degree of anthropogenic transformation of vegetation under the influence of recreational activity we used eco-cenological spectrum changing analysis. It was found that increasing homogenization of the vegetation and the occurrence of ruderal communities dominated by alien invasive species are symptomatic of the synanthropization process. The proportion of terophytes, the ratio of the proportion of adventitious species to aboriginal, and apophytes to the natural species in disturbed and homogenized forests are increasing.