trees have adapted to their local climate, but with changes in the climate may currently, or in the near future occupy climates that are sub-optimal for growth and survival. the goal of current reforestation is therefore to establish a new generation of trees with growth adapted to future climate(s). seed from twenty-five white birch (betula papyrifera marsh.) provenances collected across canada were grown in the greenhouse and observed for emergence time, germination and elongation.