It is evident that no single theory can adequately explain the complex interactions between population growth and land use. It is thus illuminating to investigate the diverse patterns of adjustment in land relations which oeeur at partieular stages of the demographie evolution. These adjustments will be more or less severe, depending on the nature of the tenure regime that determines aecess to land in a society, the level of technology, the availability of unoeeupied land, and the publie poliey environment

So, with increasing population and growing production for sale, an adverse, involutionary instead of evolutionary pattern could also emerge. A number of distinct stages 0/ development can be distinguished: 1) The oldest form is probably the shifting of cultivation and of the

farming group in one direction within a primary vegetation.