The Boreal Shield is Canada's largest ecozone. It covers almost 20% of the country's land mass, contains 43% of its commercial forestland, and accounts for 22% of the freshwater surface area. This assessment report reviews findings and highlights current trends relating to environmental stresses on the Boreal Shield ecozone. It provides direction to strengthen national programs aimed at addressing environmental concerns and developing remedial and preventative strategies, and focuses on the links of science with policy.