Urban trees assimilation efficiency and assessment of environment quality

Abstract

The conception of functional adaptation of woody plants in the changing conditions of natural ecotopes and the urban ecosystem is substantiated. The new integrated methods for estimation of the natural environment transformation under the pressure of urbanization are suggested. The objects of our research are 49 species and forms of woody plants inhabiting the urban ecosystem of Lviv, natural and artificial tree stands of Ukrainian regions. Also, we focused our attention on the anthropotransformation of microclimate, soil changing in tree plantations and problems of edaphotopes contamination. The main subject of the original plant studies were the general phenotypic functional changes in the assimilation apparatus of tree species, which can be estimated by the complex of conventional and new indicators of chemical and biochemical composition of leaf dry matter from ecotopes with different living conditions and origin. We investigated the morphological, physiological and biochemical reactions of assimilating organs of woody plants affecting their growth and development in the conditions of the Lviv city and in the natural conditions of forests and parks. As a result of long-term studies of such reactions, we have suggested an original methodological approach to elucidating the levels of phenotypic functional adaptation. Also, the ability of autochthonous and allochthonous (exotic) tree species to adapt their growth and development to new or modified anthropogenic environment has been studied out. The average level of sugars in the leaves during vegetation was considered as a normal level with the maximum at the beginning, and subsequent decrease in the middle while the minimum of content was determined at the end of the growing season. The appropriate character of starch metabolism are displayed by average levels in different species, with the maximum concentration in July and subsequent minimization of their content at the end of the growing season. The naturally determined dynamics of fiber (cellulose) concentrations implies gradual decline in the period from spring to autumn of its proportion in the leaves dry matter at the high level of concentration, similarly as in the native species. The gradual increase in the proportion of all water-soluble carbohydrates about insoluble in adapted native plants was considered as a natural. A small amount of sugars in a ratio with the general concentration of ash in the leaves at the end of the growing season, we consider as auspicious. Suggested by us clusterization of native and exotic tree species concerning of the efficiency of their introduction in different urban plantations, and depending on the degree of anthropogenic ecotope transformation, allows diversely and effectively recommend different tree species and their forms in varied scopes of application. We used indicators of phenotypic functional adaptation while inventorization of Lviv botanical gardens collections has taken place. The informative criteria for assessing the status of plants, selection of resistant local and introduced individuals with high adaptive potential were elicited by mentioned above indices. A comprehensive approach to the study of ecotope qualities is effective for assessing the acclimatization conditions for tree exotics in the botanical gardens of Western Ukraine and for developing agrotechnical measures for their cultivation.