Two different stages of demographic development with successive changes in land- use patterns and directions can be distinguished in the Beskid Niski in Poland during the past 140 years. These stages are separated by tragic events this region experienced in the 1940s (forced population resettlement). The first stage of demographic development is characterised by natural, consecutive changes comparable to other areas in the whole Carpathians. The second stage stretches from the end of World War II until the present day. The "revolutionary" character and changes initiated by this stage are nothing like these observed in other regions of the Polish Carpathians back then as well as presently (except for Bieszczady Mountains). Stemming from rapid demographic processes most changes are observed in land-use and natural environment (unexpectedly halted anthropopression), although they also affect social structures and economic processes specific for mountainous areas.