ABSTRACT.Farmers cleared approximately one third of settled forest areas within the boreal-temperate ecotone of eastern Cape Breton Island in the 19th century. Temperate hardwoods were prime settlement areas but land ownership patterns and technological dependence of saw milling on stream waters also influenced the clearing and fragmentation of hardwood areas. In the 20th century, boreal tree species invaded abandoned fields thus confounding the natural edaphic-topographic specificity of forest vegetation in ecotonal landscapes. The anthropogenic expansion of boreal tree species sustained comparable levels of wood production while reducing compositional and structural diversity of the tree stratum on original hardwood sites. Industrial forestry accelerated