The colonization and establishment of agriculture and iron production in the boreal forest inland regions of central Scandinavia from the Iron Age onwards implied that people must have overcome great difficulties. Climate is harsh, and vast areas are covered with forest and mires initially unsuitable for farming. The authors suggests that a combination of a mind-set based on infield systems occurring in the regions from where the colonizers came, and constraints imposed by the environment, promoted human niche construction processes specific for these regions. The landscape was basically structured as infields and outland, but the constraints imposed by the poor productivity of the forests necessitated extending forest grazing spatially, promoted use of outland mires for harvest of winter fodder, and ultimately led to development of secondary farms, shielings, as an innovative strategy of a spatially structured domesticated landscape.