The study of human-environment relationships in mountain areas is important for both theoretical and practical reasons, because many mountain areas suffer similar problems, namely depopulation, unemployment and natural hazards. Medium mountains constitute a special case within mountains because they are more populated but less attractive as tourist targets than high mountains. In this context, Apuseni Mts (Romania) is considered as a case study. In the present paper, we applied GIS-based, quantitative methods to characterize the strength and dynamics of human-environment interactions taking into consideration some environmental factors (elevation, relative height, slope, river distance, lithology, land cover, natural attractions) as well as historical population and recent tourism data. We found that population density has strong (r2>0.8) relationships with all relief factors (elevation, relative height, slope, river distance), and that best-fit functions are nonlinear. We outlined the varying demographic scenarios by elevation zones and interpreted the historically switching sign of population change versus elevation relationship. We proved that lithology, too, has an impact on the spatial distribution of population, though it is not independent from the relief effect. The land cover of that mainly cultural landscape is very strongly correlated with relief parameters (especially slope) that suggests a good adaptation. We pointed out the dominance of karst objects in the natural tourist potential of Apuseni Mts and explored further components (spas, heritage, towns) of real tourism as well. Finally, we concluded that the studied environmental settings in fact constrain the spatial framework of society, but socio-economic changes in history can be explained from the side of society, which conforms the theory of cultural possibilism
