The Aspen-FACE experiment in northern Wisconsin generated 11 years of data on the effects of elevated carbon dioxide and ozone levels on the growth of field-grown trees comprising maple, birch and six aspen clones; however, it is still not known how these short-term plot-level responses might play out at the landscape scale over multiple decades where competition, succession, and disturbances interact with tree-level responses. Scientists at the Forest Service's Northern Research Station used a forest landscape model (LANDIS-II) to scale-up their site level research results. The study yieled the following general principles: First, a species' or clone's productivity under future conditions is the primary determinant of its short-term dominance over other groups. Second, in the long run, longevity and shade tolerance may supersede productivity as the determinant of importance, depending on the disturbance regime. This result offers hope that, even in the face of atmospheric changes, land managers may have some control over future forest composition and carbon sequestration through modification of disturbance regimes. Third, changes in a species' or clone group's abundance were mostly gradual and none of the groups disapeared from the landscape, even under treatments for which they were poorly adapted. This result suggests that as atmospheric conditions change, abrupt extinctions will probably be rare. Four, different groups fared relatively well under different treatments. This result suggests that maintaining species and genetic diversity is a prudent forest management strategy in the face of global change. Finally, accounting for spatial processes is important because seed dispersal and establishment may limit the ability of some species to colonize available habitat.