The formation of park-monuments of landscape art was analyzed from a historical perspective. In the second half of the twentieth century, two national and nine local park-monuments of landscape art were created in Ukrainian Polissya. The purpose of PMLA is the protection and the preservation of the most prominent and valuable examples of park construction in order to use them for aesthetic, educational, scientific, environmental and health purposes. By the placement in the planning structure of inhabited localities are defined city, village and district parks. The motivation for the creation of parks was the preservation, reproduction and enrichment of tree diversity in the conditions of the Ukrainian Polissya. In the parks were planted technical, fast-growing, rare species, and species of woody plants valuable for forestry and landscape gardening with their subsequent use for scientific and economic purposes. Some of the plantations in the parks were memorable, anniversary, or dedicated to significant events (the anniversary of the October Revolution and the birthday of V.I. Lenin). In Ukrainian Polissya, there are three parks created on the basis of existing oak plantations “Klevanskyi Park”, “Park Antonivka”, “Bondaretskyi”); one - on the basis of man-made plantations with Acer platanoides L., Carpinus betulus L., Fraxinus excelsior L., Tilia cordata Mill. (“Ovrutskyi”); three parks of culture and recreation (“Horodnianskyi”, “Vysokivskyi”, “Slovianskyi”) including a meadow park (“Slovianskyi”), a children's park (“Bondaretskyi”), three arboretums (“Dubechnenskyi”, “Bairak”, “Novostavskyi dendropark”, “Zhornivskyi”), which were transformed over time, or which were granted the status of PMLA. By the size, PMLA were small, medium, and large with star, axial, fan, loop, cross-shaped and combined planning structures. In four PMLA, there were man-made and natural reservoirs, and a fountain. Five parks were combined (memorial and park of culture and rest); there were concentrated memorial complexes, monuments, and an obelisk. Plantings of parks are represented by groups, solitairs, alleys, ordinary plantings, hedges, and sometimes by groves and massifs. On the territory of 11 PMLA grew 178 species of woody plants, with 121 of them being included to the IUCN Red List. In 4 parks, since their creation the number of species increased by 75–129%; in 6 parks tree diversity decreased, with 29 to 87% of tree plant species remaining, among them 66–94% of trees were rare. 11 PMLA are valuable centers of tree diversity and unique plantings of Ukrainian Polissya; and an example of the formation of didactic, ethnographic, memorial, children's, culture and recreation, and combined parks that need further protection and expansion of the area and collection. Some parks are in need of planting reconstruction.
Speed distribution in the exhaust diffuser of the air fan