Growth Response of Spruce and Fir to Release from Suppression

Stems that are below merchantable size in climax spruce-fir stands in Alberta are generally of advanced age and are the result of long periods of suppression. The response of these stems to release from severe competition is of significance from the standpoint of a second crop. This study of the response of residual black spruce, white spruce, and alpine fir in a climax stand on North Western Pulp and Power Ltd.'s limits in west central Alberta was conducted in the tenth year following harvest. Representative trees were studied and the resulting data on the immediate and sustained response to release from suppression strongly suggest that they can be safely regarded as second growth.