Ectomycorrhizal (EM) fungal species 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; Trofymow and Outerbridge 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 this proposal we extend our research to examine how different EM fungal species, from retained trees, recolonize the regenerating forest, by studying different ages of reforested matrix, and how different levels of individual green tree retention affects recolonization, by studying Weyerhaeuser Variable Retention Adaptive Management (VRAM) experimental site at Stillwater. The VRAM experiments are the foundation of Weyerhaeuser?s AM program. Each site has 4 or 5 treatments: clearcut, uncut (old growth or 2nd growth), and two or three variable retention alternatives (20 ha minimum size for each treatment) (Beese et al. 2000; Beese et al 2003; Bunnell et al. 2003). Our proposal is consistent with the FSP Sustainability Program in that it addresses at least one of its priority themes i.e. 1.4 :?Effectiveness of stand-level structures and habitat in maintaining biodiversity?. Our research will fill some key knowledge gaps related to current stand-level harvesting practices in both old and immature stand and specifically address the questions: 1.Assuming that retained forest patches serve as refugia for EM fungi, creating an edge effect at the tree line/clearcut boundary with regards to their abundance and diversity (Trofymow and Outerbridge 2004), how quickly do EM fungi re-colonize the adjoining reforested areas, and are there changes to the species composition? 2.Does the reforested matrix assume the pre-harvest level of EM fungi with time? What rotation age of Douglas-fir stands should be used to maintain the pre-harvest biodiversity of EM fungi? 3.What level of retention is required to meet habitat needs of mature Douglas-fir EM fungi and to maintain their pre-harvest diversity? Does single-tree retention play a useful role? 4.How effective are Weyerhaeuser?s variable retention forest management practices at maintaining habitat of sufficient size needed to successfully protect EM fungi? 5.Are commercially important EM macrofungi eg. chanterelles or pine mushrooms, present in the retained mature stands? How do different levels of retention and time affect their recovery? Old-growth forests on Vancouver Island are being replaced by second-growth stands, which in turn are cut at increasingly shorter rotation ages. The survival, health and biodiversity in these new forests will depend on many biotic factors, many of those overlooked or less studied (Trofymow et al. 2003; Kremsater et al. 2003). EM fungi, being microscopic, underground, and poorly known taxonomically, are an example. This project will assess how good variable retention practices are in maintaining the essential ectomycorrhizal component of local forests, providing benefits in three areas: 1) Although the important role of EM fungi in tree physiology has been documented and known for years (Harley and Smith 1983), research has focused on seedling establishment and growth (Trofymow and van den Driessche 1991). Less is known about their importance in forest growth in the long-term. Should EM fungi be significantly depleted (as in many parts of Europe) and tree growth reductions occur, future financial losses to BC?s forestry based economy could be significant. 2) EM fungi produce many commercially important mushroom species and the sustainability of their production will depend on forest harvest practices (Pilz and Molina 2002). 3) Ectomycorrhizae and their fruiting bodies are an essential component of forest ecosystems, as a source of food for animals, of carbon f ...
Forest Investment Account (FIA). 2008. 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. FIA2008MR180
Topic: FLNRORD Research Program
Keywords: Forest, Investment, Account, (FIA), British, Columbia
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