Levels Of Growing Stock Cooperative Study in Douglas-fir – Sayward Forest and Shawnigan Lake

This document is a part of a long-running Levels-of-Growing-Stock (LOGS) Cooperative Study in Douglas-fir stands, specifically detailing findings from installations at Sayward Forest and Shawnigan Lake in British Columbia. The core objective of the LOGS study is to understand how different thinning intensities impact cumulative wood production, individual tree size, and growth ratios in young Douglas-fir stands. This progress report summarizes data from these two Canadian sites, showing that volume growth is strongly tied to the amount of growing stock retained, and that thinning significantly influences tree size distribution and live crown development, suggesting potential for future productivity gains. The study also offers comparisons between various thinning regimes and unthhinned control plots, revealing the long-term implications of silvicultural practices on forest stands.