After years of delay the book which present the results of studies carried out under project R-III-15 directed by Professor Ryszard Bohr, who died in 1987, finally appears. In his research work, Professor Bohr was mainly interested in developing basie ecological theories, in systems of naturę apprehension and in problems of application of ecological sciences in the protection of naturę and its resources. Hę was also interested in the principles of functioning of ecological systems of different scales. Among the variability and diversity of structures, hę was seeking for a universal model of their functioning. The book reflects this kind of understunding of naturę. It presents ecological systems representing different levels of organization varying in time and space. Professor Bohr was trying to find out what conditions should be fulfilled to establish harmony between mań and naturę. To do that it is necessary to study the past and present relationship between them. Therefore the book contains both papers concerning paleological, anthropological and economic problems of ecology in historical aspect and the present effects of mań's impact on ecosystems. The materials for publication were prepared in 1986. However, because of the difficult economic situation, printing of the book was not possible. Nevertheless the results arę still topical and should be presented to ecologists.