user: Question: How large is the Boreal Shield in km2?
Columns: ['Ecozone', 'Area (km²)', 'Percentage of total area', 'Percentage of land area', 'Percentage protected']
Types: ['text', 'real', 'text', 'text', 'text']
Sample row: ['Pacific Maritime', 205175.0, '1.4', '2.2', '18.87']
SQL:

assistant: SELECT "Area (km²)" FROM "Table" WHERE "Ecozone" = 'Boreal Shield';