Assessment of phyto diversity in the forests of the forest-steppe zone of Ukraine

Tree plantations near settlements unite forests and other transformed links of green infrastructure into a single network, creating habitats for biota to exist. To conduct comparative studies of anthropogenic impact on forest ecosystems, the tract ‘Vygrayivski Dachi’ was chosen, which is a complex of various biotopes and is valuable for monitoring studies of forest-steppe biota. The objective of this study was to determine changes in phytodiversity within the Vyhraivski Dachi tract along a gradient of recreational pressure in transformed forest stands dominated by Scots pine (Pinus sylvestris L.) and pedunculate oak (Quercus robur L.). Pine plantations with an admixture of oak were studied in 5 temporary trial plots according to the gradient of anthropogenic (recreational) impact. Pinus sylvestris L. are severely weakened and dry out. Only on trial plot 5 (lowest recreational load) the condition of the trees is better – Pinus sylvestris L. and Tilia cordata L. are weakened. The existing subgrowth of Quercus robur L., Tilia cordata L., Pinus sylvestris L., Carpinus betulus L. is weakened. The indicators of recreational damage to the stands decreased with reduced anthropogenic impact, while the structural diversity of ecosystems (Hstr) increased as recreational pressure decreased. The herbaceous cover of the studied stands contained 73 plant species. Four species of scale and leafy lichens have been identified. As the impact gradient decreased, tree mortality in both the canopy and understory tiers also declined. The overall adventization index was 29.2 %, decreasing along the gradient of recreational load. Phytoindication of the herbaceous tier revealed that with increasing recreational impact, the number of nitrophilous species increased which indicates thinning of the tree canopy and increased insolation.