Summary of research regarding polypore fungi

1. Preliminary Proposal for Polypore TerreWeb Research at the University of British Columbia
Summary
I am interested in contributing to the knowledge base surrounding polypore fungi, which despite their
medicinal value have attracted little ecological study. In the field, I would like to understand how forests
of different management regimes support diversity and abundance of polypore fungi, as well as
cataloging potentially new species. In what kinds of forests do medicinal polypores flourish? What is a
forest worth that provides medicine? Can medicinal fungi be used as an educational lever in promoting
the importance of Old Growth forests? I believe GPS linked photography presents an interesting multi-
media based strategy for communicating the value of Old Growth forests and an opportunity for citizen-
based research collaboration. In addition, the legacy of First Nation traditional medicine can be woven
into the project.
Secondly, I am interested in understanding the role of polypore fungi in nutrient transfer in the forest,
especially in disturbed habitats. Using some of the methods described in Suzanne Simard’s lab, nutrient
transfer could be traced and quantified between polypore mycelia and ectomycorrhizae.
Polypore Biodiversity & Medicine
Mounting health care costs and concerns of an aging population create an unprecedented opportunity
to communicate the importance of biodiversity to the public. In vitro and clinical studies are confirming
the medicinal benefits of polypore fungi: Fomitopsis pinicola, Inonotus obliquus, Fomitopsis officinalis,
Piptoporus betulinis, Trametes versicolor, Bondazewia mesenterica, Phellinus ignarius, Fomes
fomentarius, and Polyporous umbellatus among others (Stamets, 2004). Paul Stamets counts that of 204
polypore mushroom species tested, 75% were shown to be antimicrobial and 45% inhibited growth of
microorganisms (Stamets, 2002). A study published in China reviewing the past decade of mushroom
research counts 651 fungi species belonging to 182 genera with antitumor or immune-stimulating
polysaccharides (Fan, 2006). Compounds in fungi such as steroids, polysaccharides, and triterpenes
have been shown in vitro to bind to mRNA, induce apoptosis in leukemia cells, block tumor promoters,
inactivate cancer-related kinases, inhibit histamine release, increase leukocyte and neutrophil counts in
lung cancer patients, inhibit HIV protease, stimulate natural killer cells, and inhibit herpes, Pox, and
influenza viruses (Fan, 2006; Stamets, 2004). The antibiotics calvacin, campestrin, coprinol, corolin,
cortinellin, ganomycin, and sparassol have all been isolated from fungi (Stamets, 2004). The medicinal
value of the rare fungus Fomitopsis officinalis has been appreciated for hundreds of years by native
cultures and is now the center of exciting medicinal research (Stamets, 2004).Yet, it is clear that forest
management affects fungal diversity (Lindner, 2006). Younger forests and managed forests in
Scandinavia with fewer snags, trunks, and wood debris are shown to have reduced diversity and
abundance of fungi (Halme, 2010). In Finland, 37% of 230 polypores hold threatened status, but,
globally, less than five fungi are red listed by the IUCN (Halme, 2010; Schigel, 2009). In the Pacific
Northwest, Bridgeporous/oxyporous nobilissmus was the first fungus to be listed as an endangered
species in the United States by the Oregon Natural Heritage Program (Tom Volk, website).

2. Polypore Ecology
Though wood rotting fungi are responsible for 90% of the nutrient cycling of dead wood and provide
habitats and energy to myriad arthropods, bird, and other organisms; the behavior of polypore mycelia
remains a relative mystery (Carey, 1999; Selonen, 2005). It has been shown that hyphal systems of
saprotrophs and ectomycorrhizal intermingle (Agerer, 2001; Thompson, 1984), but it is unclear whether
mycorrhizae and polypore mycelia exchange nutrients. Gilled saprophytic wood-decaying fungi have
been shown to exudate mucilage that has soil binding agents, so it is possible that nutritive exudates are
also put into the rhizosphere for uptake by mycorrhizae (Caesar-Tonthat, 2002). As up to 33% of plant
photosynthate can come from root and fungal respiration (Simard, 1995), it is important to understand
how wood-based carbon is cycled back into living organisms and soil. Some wood rotting fungi (“non-
resource-restricted”) have been found to spread from substrate to substrate through hyphal expansion
and not spore dispersal (Boddy, 2008). Curiously, many polypores seem slowly parasitic and their
fruiting bodies can persist on large, seemingly healthy trees for many years. The distinction between
parasitic, saprophobic, endophytic, and mycorrhizal functions is not always clear (Read, 2002). It does
appear that some polypores monopolize inoculation of a substrate through inhibitory activity over other
fungi and microbes; saprotrophic fungi can inhibit mycorrhizal colonization (Shaw, 1995). Cooke showed
in 1948 that temperature and moisture are more constant in dead tree trunks than in the ground
(Lindner, 2006). Forests that have been ravaged by insect pests or disease often provide an excess of dry
fuel load encouraging forest fires. It is unclear whether expedited polypore inoculation could bring
moisture to dry substrates and reduce the risk of forest fires, though intentional inoculation has been
carried out in the field (Carey, 1999).
Field Study: Haida Gwaii
Though fungal species are estimated to be the second largest group of organisms on Earth and the
second largest source of biomass in terrestrial ecosystems, it is estimated that only 10% of fungi have
been identified and categorized (Cannon&Hawksworth, 1995). Little quantitative sampling of polypore
fungi has occurred in N. America (Lindner, 2006). I propose a GPS linked photography assay to map the
density and diversity of such fungi. As polypores have a multi-year lifespan, they lend themselves to
longitudinal research unlike fruiting bodies of other fungi, which grow only in very specific conditions. I
would set up transects in forests of different age and management regimes. Long continuity (100 year
old dead wood substrates), short continuity (100 year or younger), or no continuity of managed forests
were the different management demarcations used in a Finnish study (Jonsell, 2002). Of course
diameter at breast height can also be used. The forests can also be qualitatively separated by the
diameter categories for woody debris (Lindner, 2006). Typically the old growth stands will provide more
polypore habitat in tree-fall mounds, snags, cavity trees, large diameter trees, and standing as well as
downed coarse wood (Lindner, 2006). Other data could be recorded using a CRIO Datalogger in
monitoring environmental conditions of interest including rainfall, air/soil temperature, soil water,
forest tree height, substrate diameter, substrate species, etc. Such a study was carried out with 15
different stands sampled in 100m x 60m plots (46/255 fungi could not be assigned a species name!);
another study chose 21 sites (Lindner 2006; Selonen, 2005). This same study recommends a 2 year
sampling in order to characterize annual variations. Other studies use progressively smaller transects for

3. increasingly detailed data (e.g. 5mx5m section of a plot to measure every piece of woody substrate).
Methods have been developed for quantifying small refuse volume as a percentage of ground covered
(Laasenatio, 1982). Contrasting a managed spruce forest with a clear cut stand, a Finnish researcher
found greatest abundance and diversity at clear cut sites (Selonen, 2005). If a species focus is required, I
believe that the Ganoderma and Fomitposis genera would be good candidates as they have proven
medicinal properties and are abundant. Taking tissue samples for ITS region markers would provide an
opportunity for genetic biogeography and could lead to fascinating insights into polypore dispersal and
evolution. Finally, if novel bracket fungi were discovered, tissue samples could be brought into culture
and then submitted for testing against microbes. The methods for extraction and primary anti-viral
testing are outlined at length by Paul Stamets (Stamets, 2004).
Lab Study: Nutrient Cycling
Isotope pulsing methodology seems potentially useful for examining the nutrient-cycling interaction
between the hyphae of mycorhizzal and polypore fungi. Myceliated snags from the wild (or lab
inoculated substrates) could be taken to the lab and used as a substrate for seedling plantings. Holes
could be made in the snag and filled with autoclaved soil. Both Douglas fir and paper birch could be used
and isotope pulsing (as described by Simard, 1995) could be used to see if C14
/C13
is absorbed into the
polypore mycelium. To check the other direction of nutrient transfer, radioactive amino acids or sugars
could be added to the polypore-inoculated substrate prior to seedling planting. After a chase period the
seedlings could be harvested and separated into tissue factions with C13
measured by mass
spectrometer and C14
measured by combustion/liquid scintillation. Finally, growth rates of these
seedlings could be compared to a soil only control. Another study explains a method for tracing N
translocation using C14
based amino acid and watching the movement counting photon emissions across
a screen (Watkinson, 2006). Other studies used glass microcosms to examine the interaction of seedling-
innoculated mycorrhizae with saprotrophic-mycelia infected block substrates buried in the soil (Lindahl,
2001). Each type of mycelium was labeled with 32
P whose movement was imaged with autoradiography.
The wood block sources of isotope were also digested and examined with a scintillation counter. Growth
rate and distance of saprophytic fungi were shown to be largely dependent on substrate size, which
would have interesting implications for polypore fungi innervating an entire snag or log. This experiment
could be replicated with polypore myceliated wood blocks and compared to controls. The Lindahl study
postulated that clear cut stands provide ample fuel for saprophytic fungi as to inhibit the activity of
mycorrhizal fungi, partially supported by the observation of higher seedling survival in replanting areas
where slash has been removed from the site (Lindahl, 2001). Yet, the authors also acknowledge that
nurse logs, once depleted of their nutrients, may provide beneficial habitat for seedlings and
mycorrhizae via consolidated nutrients in dead mycelia.
Microcosms from Lindahl
1999 with saprophytic
inoculated substrate on
bottom: Left) shows when
P tracer was added to
saprophytic substrate b)
when added to
mycorrhizae

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