Сarbon sequestration in young pedunculate oak (Quercus robur L.) trees stems growing in a Feofania Park stand were reconstructed in this article. We used standard dendrochronological approaches to obtain tree-ring and basal area chronologies (1932–2015). The mean radial growth rate of studied trees at age 65 was 3.18±1.06 mm per year and ranged from 1.86 to 5.49 mm per year. In 2015, a carbon mass in an oak stem reached mean value of 366±176 kg and ranged between 167 and 922 kg depending from a stem diameter. Pedunculate oak fixating ability increases from 2 and 5 kg carbon per year at age 20 and 30 to 10 kg carbon per year at 45–72.

The geographical structure of the flora of the National Nature Park «Pyryatynsky» is analyzed in the paper. Typological system of plant species areas according to zonal characteristics, horionimic element and its activity is developed. It was found that species of flora National Park are distributed among 11 type, 1 subtype groups and 39 areas. Horological core of the flora of the National Nature Park «Pyryatynsky» contain Eurasian and Holarctic species with areas in temporal and submeridional zones. A significant part of flora belong to Palearctical, Euro-Mediterranean-Iran-Turanian and European geoelements. Flora of the National Nature Park «Pyryatynsky» is close to the Mediterranean flora. However, part of the Eurasian steppe and desert-steppe elements is minimal, due to the latitudinal location of NNP and total destruction characteristic of these types of florokomplexes. The increased role of cosmopolitical species is the result of penetration of alien flora elements. Location of the National Nature Park «Pyryatynsky» in the valley of Uday and on the verge of fitochorions of regional scale helps to enrich the flora and indicate a significant sozological value of this natural protected area.

Clarified syntaxonomical structure of sozological of communities halo nitrophylous (Cakiletea maritimae), psamophytic (Ammophiletea) and psamophytic steppe (Festucetea vaginatae) vegetation of Dzharylgach island is given. They are represented by six associations and one basal community that belong to three unions, three orders and three classes. There is a classification scheme, phytocenotic and synoptic tables, given characteristics within the classes and associations, assessed degree of rarity by sozological features of diagnostic species. New for the island syntaxons, class Cakiletea maritimae, associations Lactuco tataricae-Cakiletum euxinae, Tournefortietum sibiricae and community Trachomitum venetum subsp. russanoviiwere found.

Association Violo hirtae–Quercetum roboris is discribed as new for science from the basin of the lower Sula. Its xeromesophilic oak forests which are represented by three subassociations. They are attributed to the Aceri tatarici-Quercion roboris alliance. They are rare and occupy the driest ecotops of the plankers (the fourth floodplain terraces) above the ditches, between the ridges of beams, at the top of the slopes. They perform important anti-erosion and soil protection functions.

Іnformation about distribution of rare species Scopolia carniolica in Ukrainіan flora on the Dnieper Upland (the Kiev, Zhitomir, Cherkassy and Kirovograd regions) is generalized. 20 locations of the species have been found within the region for the entire period of floristic studies. Among them, four locations have already been disappeared. One new locality has been described. Six local populations of S. carniolica are small or medium-sized and some of them have threatening status. 

The meadow vegetation of the Kyiv city waters and its rare communities, which belong to seven associations Agrostio vinealis-Calamagrostietum epigei, Festucetum pratensis, Koelerio-Agrostietum vinealis, Lysimachio vulgaris-Filipenduletum, Agrostio giganteae-Festucetum pratensis, Poetum pratensis, Poo palustris-Alopecuretum pratensis were researched. Iris sibirica from the Red Data Book of Ukraine was found in these communities. It has large projective coverage and constancy in Festucetum pratensis and Lysimachio vulgaris-Filipenduletum. III protection category is proposed to be included into new edition of the Green Data Book of Ukraine. Other five associations need to IV protection category.

82 species of lichens and 12 species of lichenicolous fungi are protected on the territory of the National Nature Park «Biloberezhzhya Svyatoslavа». The lichen Athallia alnetorum and lichenicolous fungus Pronectria xanthoriae are the first time reported to Ukraine, 12 species are new for Mykolaiv region, 71 species are new for the National Nature Park. Among lichens, 66 species are corticolous and they were found on the bark of Alnus glutinosa, Pinus sylvestris, Populus tremula, Quercus robur, Salix alba. 12 terricolous species cover sand dunes and sandy steppe areas. 4 species were found on artificial stone substrate. Cetraria aculeata, Seirophora lacunosa, Xanthoparmelia camtschadalis are included into the Red Data Book of Ukraine. Chaenotheca trichialis, Parmelina quercina, Usnea hirta, Xanthoparmelia pokornyi from «Red list» of the Mykolaiv region are protected. 

The modern data on the discomycetes diversity of Kharkiv Forest-Steppe are summarized. The checklist is based on the analysis of literature data starting from the middle XIX century, critical revision of materials from scientific herbarium CWU Myc and own studies performed in 2010-2017 . The list includes 254 species of discomycetes belonging to 115 genera, 35 families, 8 orders and 5 classes of Ascomycota. Among them 134 species are new to Kharkiv Forest-Steppe, 43 are new to Left Bank Ukraine and 36 species are first time reported to Ukraine.