Bulkley Valley Research Centre - Science in the Public Interest

Structural Recruitment: Factors Affecting Survival and Growth of Residual Immature Trees after Clearcut Overstory Harvesting

Project Reference Number: 2006-23

Project Status: Complete

Led by: Ruth Lloyd, Mackenzie

Melissa Todd, Victoria

Funder: Forest Investment Account - Forest Science Program

In recent years, there has been increased emphasis on retention of structural features such as coarse woody debris and immature understory trees during clearcut harvesting in the sub-boreal Interior. These features serve to “lifeboat” species and processes during early seral stages and will enrich the developing stand with structural features that would otherwise be absent. Retention of immature understory trees may also contribute to future recruitment of large live and dead stems. Little research has been done on the persistence of residual immature trees and their contribution to structural diversity through the life of the regenerating stand in clearcuts, where mortality may be more related to windthrow and sunscald rather than competition and suppression.

With this project we will investigate factors affecting the survival and development of residual immature subalpine fir trees in areas clearcut between 1995 and 2000 and to use the results to guide abundance and configuration of future residual immature tree retention in clearcut areas. We expect that tree morphology (height, diameter) and configuration of retention (patch vs single tree) will affect the survival and growth of immature residual trees retained after harvest. We expect to test this by collecting measures of growth and survival for residual immature trees of varying sizes and in various retention configurations. We also describe the risk of windthrow as related to soil conditions, distance to timbered edge and tree crown characteristics.

Related Reports

Publication Date Report Title Authors
2006 Structural Recruitment: Factors affecting survival and growth of residual immature trees after clearcut overstory harvesting Ruth Lloyd, Melissa Todd, and Jeffrey Meggs