environment canada subdivides british columbia into a system of ecozones, each containing smaller ecoregions. the ecozones within british columbia include the pacific marine, pacific maritime, boreal cordillera, montane cordillera, taiga plains, and boreal plains ecozones. the system used was established by the trilateral commission for environmental cooperation and as such is parallel to that used by the environmental protection agency in the united states, though their system uses different names for the same ecozones and ecoregions, and to a similar ecoregional subdivision of mexico.