Forest Investment Account (FIA) - Forest Science Program
FIA Project Y083183

    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
Project lead: Trofymow, J.A. Tony (Natural Resources Canada)
Subject: Forest Investment Account (FIA), British Columbia
Series: Forest Investment Account (FIA) - Forest Science Program
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 for achlorophyllous plants (eg. Allotropa sp and the endangered phantom orchid), and thus may play a role in maintaining diversity of other species in the forest (Molina et al. 1992; Molina et al. 2001). Research on indicators of sustainability, particularly focal species, is a critical research need for the forest industry. This research is part of Weyerhaeuser’s AM program, which has been described by independent scientists as “the most sophisticated application of ecological principles to forest management of which I am aware” (Dr. Jerry Franklin, Univ. of Washington) and “the best, most well planned and carefully executed adaptive management program underway in forests anywhere in the world” (Dr. David Lindenmayer, Australia National University). This project can be done at far lower cost (e.g., access to additional data, operational-size experimental treatments) with greater benefits than if it were a ‘stand-alone’ study.
REFERENCES Arora, D. 1986. Mushrooms Demystified. Ten Speed Press, Berkeley, Calif. Agerer, R. (edit.). 1987a. Colour atlas of ectomycorrhizae. Vol. 1-2. Einhorn –Verlag, Munich. Agerer, R. (edit.). 1987b. Descriptions of ectomycorrhizae. Vol. 1-4. Einhorn –Verlag, Munich. Beese W.J, B.G. Dunsworth, N.J. Smith. August 2000. Variable Retention Monitoring and Adaptive Management. A framework for treatment comparison blocks. VR-Amblocks.doc. Beese, W.J., Dunsworth B.G., Zielke, K., Bancroft, B., 2003. Maintaining attributes of old –growth forests in coastal B.C. through variable retention. Breitenbach, J. and F. Krunzlin. 1984 –2000. Fungi of Switzerland. A contribution to the knowledge of the fungal flora of Switzerland. Vol. 1 Ascomycetes, Vol. 2 Non gilled fungi, Vol. 3 Boletes and agarics 1st part, Vol. 4 Agarics 2nd part, and Vol. 5 Cortinariaceae. Edition Mykologia Lucerne, Switzerland. Bunnell, F., Dunsworth, G., Huggard, D., Kremsater, L. 2003. Learning to sustain biological diversity on Weyerhaeuser’s Coastal Tenure. Unpublished Forest Project Report. Goodman, D.M. 1995 Diversity of ectomycorrhizae in old-growth and mature stands of Douglas-fir on southeastern Vancouver Island. Ph.D. Dissertation, Department of Biology, University of Victoria, Victoria, B.C. Goodman, D. M., and Trofymow, J. A. 1998. Comparison of communities of ectomycorrhizal fungi in old growth and mature stands of Douglas-fir at two sites on southern Vancouver Island. Can. J. For. Res. 28: 574-581. Goodman, D.M., Durall, D.M., Trofymow, J.A., Berch, S.M.(edit.). 1996 - 2000. A manual of concise descriptions of North American ectomycorrhizae. Mycologue Publications. Harley, J.L. and Smith, S.E. 1983. Mycorrhizal symbiosis. Academic Press, London. Jones, M. D., Hagerman, S. M., and Gillespie, M. 2002. Ectomycorrhizal colonization and richness of previously colonized, containerized Picea engelmannii does not vary across clearcuts when planted in mechanically site-prepared mounds. Can. J. For. Res. 32: 1425-1433. Kohm, K.A. and Franklin, J.F. (edit.) 1997. Creating a forestry for the 21st century. The science of ecosystem management. Island Press, Washington, DC. Kranabetter, J. M., Hayden, S. and Wright, E. F. 1999. A comparison of ectomycorrhizal communities from three conifer species planted on forest gap edges. Can. J. Bot. 77: 1193-1198. Kremsater, L., Bunnell, F., Huggard, D., and Dunsworth G. 2003. Indicators to assess biological diversity: Weyerhaeuser’s coastal British Columbia forest project. The Forestry Chronicle 79 (3): 590-601. Krebs, C. J. 1989. Ecological Methodology. Harper Collins Publishers. 654pp. Molina R., D. Pilz, J. Smith, S. Dunham, T. Dreisbach, T. O’Dell, and M. Castellano. 2001. Conservation and management of forest fungi in the Pacific Northwestern United States: an integrated ecosystem approach. In: Fungal Conservation Issues and Solutions. A Special Volume of the British Mycological Society. Moore D., M. M. Nauta, S. E. Evans, and M. Rotheroe (editors). Cambridge University Press. Outerbridge, R.A. and J.A.Trofymow. 2004. Diversity of ectomycorrhizae on experimentally planted Douglas-fir seedlings in variable retention forestry sites on southern Vancouver Island. Can. J. Bot. 82: 1671-1681. Outerbridge R., J.A. Trofymow, and H. Kope. 2001. Diversity of ectomycorrhizae on planted seedlings in variable retention forestry sites: Results of pilot study and description of design of future experiment. Unpublished report to Weyerhaeuser, CFS, Pacific Forestry Centre, Victoria. Unpublished. Phillips, R. 1991. Mushrooms of North America. Little, Brown and Company, London. Pilz, D. P. and Perry, D. A. 1984. Impact of clear-cutting and slash-burning on ectomycorrhizal associations of Douglas-fir seedlings. Can. J. For. Res. 14: 94-100. Pilz, D. and R. Molina. 2002. Commercial harvests of edible mushrooms from the forests of the Pacific Northwest United States: issues, management, and monitoring for sustainability. Forest Ecology and Management 155:3-16. Redhead, S.A. 1997. Macrofungi of British Columbia: Requirements for Inventory. Res. Br., B.C. Min. of For., and Wildl. Br., B.C. Min. Environ. Lands and Parks, Victoria, B.C. Work. Pap. 28/1997. 119 pp. Trofymow, J. A. and van den Driessche, R. 1991. Mycorrhizas. In: Mineral nutrition of conifer seedlings. Edited by R. van den Driessche, CRC Press, Boston. pp. 183-227. Trofymow J.A., Addison, J., Blackwell B.A., He, F., Preston, C.A., and Marshall, V. 2003. Attributes and indicators of old-growth and successional Douglas-fir forests on Vancouver Island. Environmental Reviews 11S:187-204.
Related projects:  FSP_Y061183FSP_Y072183
Contact: Trofymow, J.A., (250) 363-0677,


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Updated August 16, 2010 

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