Forest Investment Account (FIA) - Forest Science Program
FIA Project Y082310

    Developing Molecular Tools to Help Determine the Effect of Natural Disturbance on Pine Mushroom (NTFP) Distribution and Sustainability
Project lead: Chapman, Bill (BC Ministry of Forests and Range)
Contributing Authors: Chapman, Bill K.; Bravi, Becky
Subject: Forest Investment Account (FIA), British Columbia
Series: Forest Investment Account (FIA) - Forest Science Program
The focus of this research is to develop tools to allow more effective monitoring of the effects of the current mountain pine beetle epidemic on pine mushrooms. In the mid 1980ís pine mushrooms were found in commercial quantities in many parts of British Columbia and a harvest and export industry was developed (Betty Shore, personal communication, September 1999). Since that time the Pine Mushroom (Tricholoma magnivelare) has become the most valuable non-timber forest product in British Columbia (Wills and Lipsey, 1999, particularly to First Nations. The current Mountain Pine Beetle epidemic and the associated salvage harvest operations threaten the sustainability of the pine mushroom industry at an unprecedented scale across the province. Some productive areas are experiencing direct loss of habitat as mature to old pine stands die or are salvage harvested while others are experiencing the indirect effect of increased harvest pressure as pickers concentrate on the remaining patches. Pine mushroom producing patches have been studied intensively in the West Chilcotin for about 8 years, as a joint effort between the Ulkatcho First Nation and the BC MOFR (Chapman and Bravi 2003a). Pine mushrooms occupy mature to old pine stands in this region. Data collected during the pine mushroom study and again in 2005 after severe MPB attack confirmed that virtually all of the research plots in the West Chilcotin had been attacked by mountain pine beetle. Pine mushroom production occurs in mature to old pine dominated stands, the same stands preferentially attacked by mountain pine beetles. Our data also show that though many of the patches had been attacked by beetle, infested mushroom patches retain some of the same complex structure they had before the beetle attack, i.e., some large escape trees, many dead snags, a reasonably intact understory and a high proportion of mistletoe infected regeneration (Chapman and Bravi 2003a). It is therefore probable that many of the MPB affected patches may continue to produce mushrooms, or will begin to produce mushrooms again very soon if they are not salvage harvested. As a result of past research efforts, management recommendations have been made at both the landscape and stand level in the West Chilcotin (Chapman and Bravi 2003b). However, a major challenge to monitoring and managing pine mushroom production in pine mushroom patches is that T. magnivelare does not fruit regularly. In some patches throughout the province pine mushrooms have not produced fruit bodies for >5 years with production beginning again after that time and pine mushroom production does not begin in stands until they have reached 70 years of age or older(unpublished data, Olivetto 1999). Because mountain pine beetle salvage operations and associated expedited harvest will occur over a relatively short time period (Pedersen 2004) it is probable that large areas of pine mushroom habitat could be rendered non-productive if they are not identified very soon. In 2005 a project was implemented using provincial mountain pine beetle funding to determine if it is possible to use T. magnivelare infected short roots to identify pine mushroom persistence in MPB affected patches where fruiting was not observed in the fall of 2005, (Bravi 2006). The overall conclusion of the study was that root morphologies could be used to monitor persistence in stands. However,the complexity of the technique limits its utility to trained technicians who are experienced in root morphology descriptions. Also, questions arose as to whether or not other fungal root associations in the area form the same morphologies. T.zelleri roots were collected and microscopically examined. Roots infected with T. zelleri exhibited similar morphologies to those infected by T. magnivelare. This is of particular importance as these two mushroom species occupy the same niche across the landscape and are often found fruiting together. Genetic analysis used in the study to confirm the findings of the morphologies was conducted but was inconclusive. A non-specific fungal primer of the ITS region was used for this preliminary analysis. Problems associated with using general fungal primers are that they do not incur a high level of specificity and therefore may not identify specific species presence adequately or in all cases. This could lead to false negative results for presence (Berbee, personal communication, 2006). Increasing our ability to easily and accurately determine pine mushroom persistence and presence can be achieved through the development of molecular tools. Genetic detection methods such as real-time PCR have been effectively used for the rapid and specific identification of fungi in roots (Osman and Rowhani 2005; Abd-Elsalm, Asran-Amal, Schnieder, Migheli and Verreet 2005; Pasquali, Piatt, Gullino and Garibaldi 2006). Species-specific primers are currently the best tools for ensuring specificity and have been successfully developed for other Tricholoma species (Kikuchi, Matsushita, Guerin-Laguette, Ohta and Suzuki 2000 and Terashima and Nakai 1996). In Situ hybridization will also be examined as possible tool for identifying pine mushroom infected roots (O,Connell 2002). We had initially decided to use a monoclonal antibody stain as quick identification tool but discovered that refining that staining procedure was very slow. We feel that the RT-PCR in conjuntio with the In Situ hybridization will give us the same information with less development time. These tools will also be used to identify pine mushroom presence in stands where production was not previously known to occur. Being able to find new areas to harvest pine mushroom could expand the industry and could help mitigate the effects from the predicted timber shortfall associated with the mountain pine beetle epidemic as pine mushroom patches can be very valuable. The use of predictive maps such as the one developed in the West Chilcotin by Chapman and Bravi (Chapman and Bravi, 2003) could be used to identify areas of suitable habitat for pine mushrooms and point to areas that should be more intensively surveyed for pine mushroom presence using the tools developed through this research.
Related projects:  FSP_Y071310
Contact: Chapman, Bill, (250) 398-4718,


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Updated August 16, 2010 

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