As climate changes, the distribution of vegetation zones will change. The doubled CO₂ map (below) shows the vegetation that would be expected if climate were the only determinant of vegetation type. The temperate forest zone would expand northwards in Atlantic Canada; however, soil conditions and life cycles limit rates of forest migration. Existing forests will be stressed before they can migrate.

Changes in forest and grassland climate zone boundaries (Adapted from: B. Rizzo et E. Wiken, 1992)

Bicknell's Thrush (Photograph courtesy of R. Elliot, Environment Canada)

As ecosystems are disrupted, some components will move north, but others will stay. Invasive and colonizing species will move first; 'sensitive' species will not be able to move. Some wildlife populations will go extinct.

Climate change will directly affect birds in Atlantic Canada, for example...

Harlequin duck (Photograph courtesy of Environment Canada, Environmental Conservation Branch)

Changes in river flow - earlier break-up, stronger spring freshet, and reduced summer flow - could impact the endangered Harlequin duck of Labrador.

Will climate change affect bird migration?

World (Source : NASA)

Semipalmated sandpiper (Photograph courtesy of T. Beck)