This project, developed in partnership between the (former) Weyerhaeuser?s Coast Forest Strategy team and researchers from the UBC Centre for Applied Conservation Research, is part of an innovative, ecologically-based, forest management program for the company?s BC coastal tenures. The goal of the program is to sustain biodiversity and associated values while economically harvesting timber. The three biological criteria used to determine weather the program is achieving this goal include assessment of: ecosystem representation, habitat structures and indicator species. This project focuses on the role of ectomycorrhizal fungi (EM fungi) as indicator species. Ectomycorrhizae are an important component of biodiversity for assessing the effects of variable retention (VR) forestry (Kohm and Franklin 1997). In our previous work (Outerbridge et al. 2001; Outerbridge and Trofymow 2004) on south Vancouver Island (Weyerhaeuser?s Shawnigan and Nanaimo River Operations), we found clear evidence of edge effects in VR sites. We observed significantly lower abundance and diversity of EM fungi with increased distance from the retained forest patches. In the current project we extend our research to examine how different levels of individual green tree retention affects EM diversity (Stillwater study) and how EM fungal species on retained trees, recolonize the regenerating forest, by studying different ages of reforested matrix (Northwest Bay and Koksilah study) (Beese et al. 2000; Beese et al 2003; Bunnell et al. 2003). We put forward two hypotheses: 1) That survival and abundance of ectomycorrhizal species will increase with the increased number of retained live trees in harvested areas; 2) That EM diversity in the 57 to 87-year age group will have recover and edge effects diminish with time until EM diversity more closely resemble that in the adjacent mature or old growth forest (90 ? 200+ years).
Trofymow, J.A. (Tony). 2006. Assessment of the effectiveness of green tree retention in maintaining the diversity of and promoting the recolonization by ectomycorrhizal fungal species into harvested areas of coastal forest. Forest Investment Account (FIA) - Forest Science Program. Forest Investment Account Report. FIA2006MR132