Self-replacement in old-growth white pine forests of Temagami, Ontario

Abstract

Surveys of both live and dead vegetation were conducted to examine long-term successional trends in old-growth white pine forest. The forest successional trend, for a period of possibly up to seven centuries, shows that white pine has been the dominant species over this time period indicating that these old-growth white pine forests have been self-replacing. Size-class analysis was used as an indicator of age-class structure. Results of this analysis show that the old-growth white pine stands are at least partially uneven-aged. The uneven-aged condition, resulting from continuous recruitment, was most likely facilitated by local disturbances such as small surface fires, windthrown trees and the death of large individual trees through biological or other agents. These findings cast some doubt on the silvicultural theory that catastrophic fire is the only primary facilitator of natural white pine regeneration. Selection logging in white pine forest may make better use of the various non-catastrophic mechanisms of natural white pine regeneration. It is unlikely, however, that the old-growth condition can be maintained or enhanced under any cutting regime. In addition to the production of fibre, old-growth forests are valuable components of the landscape from both a functional ecological perspective and a scientific perspective.