Аналіз дендрофлори плоских озеленених дахів екстенсивного типу в місті Львові

Abstract

Roof gardens, which perform many useful functions for humans, are one of the most modern ways to create a harmonious and aesthetic environment in cities. Therefore, the study of the list of woody plants that successfully overwinter and tolerate critical summer temperatures on the roofs with minimal tending, is an important task for green space workers. The taxonomic composition of the dendroflora of 24 flat of extensive type in the city of Lviv at heights from 5 to 40 m was studied and its system-structural analysis was performed. It was found that the dendroflora of the examined objects was composed of 167 taxonomic units of woody plants (of which 109 species, 76 cultivars, 10 hybrids). The family Rosaceae Juss is numerically superior (13 genera (21.1% of the total number of genera), 32 species and hybrids (26.9%); by the number of cultivars, the Cupressaceae family dominates - 32 cultivars (42.7%). The genus Juniperus dominates in the genus spectrum in terms of the number of species, hybrids and cultivars - 10 species (8.8% of the total number), 13 cultivars (17.1%). For greening the roofs, 93 species and cultivars of deciduous plants, 74 evergreen phanerophytes (28 mesophanerophytes, 69 microfanerophytes, 60 nanophanerophytes and 10 woody lianas) were used. According to the results of the chorological analysis, it was found that species from the East Asian region and North America predominate on the roofs, indigenous species are practically not used. The plant compositions on the roofs are dominated by species regionalized for USDA-frost resistance zones 4 and 5, while the territory of Lviv lies within zone 6. Our 4-year observations proved the success of the introduction on roofs of species of a higher USDA zone than that defined for Lviv. Further study of the dendroflora of green roofs is very important, taking into account several points: the system-structural patterns of species selection for greenery have not been fully clarified; methods of specific introduction of plants on roofs and the possibility of their acclimatization, which is different from terrestrial objects, have not been tested; the possibilities of introducing a list of plants that are not found in garden and park compositions of the city have not been fully studied. Compositional solutions of green roofs are determined by various ways of planting plants - directly into the substrate, in beds or containers raised above the surface. Such studies highlight the peculiarities of the taxonomic composition and structure of the dendroflora of green roofs, which will make it possible to significantly adjust the agronomic techniques of plant maintenance and identify the most promising group of woody plants for greening roofs.