The dissertation research is devoted to the study of the meadow flora of the Romny-Poltava geobotanical district. The species composition of the flora, which includes 601 species, 306 genera, 66 families, 2 divisions, has been determined. The ten leading families by the number of species include Asteraceae, Poaceae, Fabaceae, Lamiaceae, Caryophyllaceae, Scrophulariaceae, Brassicaceae, Cyperaceae, Rosaceae, Ranunculaceae, which together account for 410 species (68,2%). The ten leading families by the number of genera in the families include Asteraceae, Poaceae, Lamiaceae, Fabaceae, Brassicaceae, Apiaceae, Caryophyllaceae, Rosaceae, Ranunculaceae, Scrophulariaceae, which together comprise 206 genera (66,9%). The genus Carex L. is the only polymorphic genus (16 species; 5,2%).
The biomorphological structure of the flora has been established. The dominant plants are herbaceous perennials (391 species; 65%), hemicryptophytes (361; 60%), polycarpics (438; 72,9%), summergreen (368; 61,2%), semirosette (301; 50,1%), rod (329; 54,7%), rhizome (246; 40,9%) plants.
The analysis of the ecological structure of the flora shows that submesophytes (174 species; 28,9%), hemihydrocontrastophytes (227; 37,8%) and hemihydrocontrastophobes (226; 37,6%), subacidophytes (275; 45,8%), semiotrophs (288; 48%), hemicarbonatophobes (235; 39,1%), heminitrophiles (297; 49,4%), subaerophiles (305; 50,7%), submesotherms (309; 51,4%), subaridophiles (233; 38,8%), hemicontinentals (258; 42,9%), subcryophiles (302; 50,2%), and subheliophiles (493; 82%).
The geographical features of the flora were studied, and the dominance of the boreal-meridional (156 species; 26%) and temperate-meridional (154; 25,6%), Eurasian (282; 46,9%), indifferent (263; 43,7%) groups was revealed.
It was found that the synanthropic fraction of the meadow flora includes 265 species (44,1%). The apophytic fraction is 162 species (61,1%). Hemiapophytes were found in 73 species (45%). The adventitious fraction is 103 species (38,9%), among which archaeophytes (57 species; 55,3%), xenophytes (81; 78,6%), epecophytes (66; 64,1%) prevail.
The systematic structure of the synanthropic fraction has been established. The species composition is represented by 265 species, 167 genera, 40 families, 28 orders, 3 classes and 2 divisions. The spectrum of leading families by the number of species is represented by Asteraceae, Poaceae, Brassicaceae, Fabaceae, Lamiaceae, Caryophyllaceae, Scrophulariaceae, Ranunculaceae, Rosaceae, Boraginaceae, Polygonaceae, which together comprise 203 species (76,7%). Vicia L. is the most complete genus (7 species; 2,6%).
The analysis of the biomorphological structure of the synanthropic fraction showed the predominance of herbaceous plants (251 species; 94,7%), hemicryptophytes (137; 51,7%), monocarpic plants (137; 51,7%), semirosette plants (132; 49,8%), rod plants (187; 70,5%), plants without modifications of underground shoots (114; 43%) The most common way of spreading fruits and diasporas is anemochory (146; 55%).
The ecological features of synanthropic flora were studied. Among the edaphic factors, the leading position is occupied by submesophytes (95 species; 35,9%), hemihydrocontrastophytes (120; 45,3%), subacidophytes (135; 50,9%), semiotrophs (131; 49,4%), acarbonatophytes (107; 40,4%), heminitrophs (135; 51%), and subaerophytes (154; 58,1%). Among the climatic factors, submesotherms (148; 55,8%), subaridophytes (97; 36,6%), hemicontinentals (122; 46%), subcryophytes (126; 47,5%), subheliophytes (229; 86,4%) prevail.
The analysis of the adventitious fraction of flora by primary habitat showed that the Mediterranean group is the most species-rich (24 species; 23,3%).
Among the adventitious fraction, 26 species of highly active invasive plants were identified. Some of their biomorphological and ecological features were analyzed. 9 species-transformers were identified.
The degree of anthropic transformation was analyzed based on the calculations of the indices of synanthropization (44%), apophytization (27%), anthropophytization (17,1%), archaeophytization (7,7%), modernization (44,7%). The degree of hemerobia was determined, with the oligohermobia group dominating (285 species; 47,4%).
In the studied meadows, 22 rare species (3,7%) were found. The systematic, biomorphological, ecological and geographical features of the rare component were analyzed. The main threats to meadowlands are identified, principles and measures for the conservation of meadow flora and rare species are proposed. The creation of 5 botanical reserves of local importance and the expansion of the area of 2 reserves are substantiated.
It is established that meadow phytocenoses provide the following ecosystem services: regulation and maintenance services, supply services, cultural and social services.
