This study is a part of the contest work on The Zielonka Primeval Forest versus the growth of Poznan. The main aim of the contest was to build up the most plausible concept of contact area management and to invent methods of restriction of the negative effect of urban functions developing in the neighbourhood of protected forestland, including the Zielonka Primeval Forest, on natural functions of these areas. The objective of the present considerations is to establish the methodological base for the purpose of: laying down the principles of functioning of the natural system Zielonka Primeval Forest - urbanized areas - Warta Valley; delimiting interrelationships in such a system; and protecting the natural system against urbanization effects. The starting point is to consider the natural environment to be a system which constitutes a certain dynamic whole in which particular elements are interrelated in a cause-and-effect chain. A spatial unit, ie a geosystem (catchment), is an area subjected to analysis. The research should be of temporal-spatial nature since it would allow recognition of present-day environment-modelling processes and establishment of principles of environment functioning in the existing physio-geographical setting.