Chapter 2: The American Matsutake
Distribution and Tree Host
|The distribution of American matsutake has been documented by several
researchers. Zeiler and Togashi (1934) published the first comprehensive treatment of Japanese
and American matsutake species, noting tree associates and occurrence in North
America. Ohara (1977), Kinugawa and Goto (1978), Ogawa (1979), Smith (1979),
Redhead (1984, 1989), Villarreal and Perez-Moreno (1989), and Villarreal (1994)
provide additional information.
The distribution of the American matsutake coincides with the northern coniferous
forest belt (or taiga), running east-west across Canada, and temperate conifer
forests extending southward along the Appalachian, Rocky, Cascade and Pacific
Coast mountain ranges. It is found under a variety of conifers with which it forms
mycorrhizae. Among the reported tree associates are Douglas-fir, western hemlock,
grand fir, Shasta red fir, Pacific silver fir, Engelmann spruce, white spruce, jack pine,
red pine, sugar pine, ponderosa pine, inland lodgepole pine, and coastal shore pine.
In southwestern Oregon and along the coast of northern California, it often associates
with tanoak. Inland, the distribution continues south through the Rocky Mountains
into high-elevation pine and fir forests in the mountains of Mexico.
Tricholoma caligatum is much more sporadic in occurrence but generally follows
the same distribution pattern. It also grows in pure coniferous stands, mixed stands of
conifers and hardwoods, and in pure hardwood stands (the latter common in the
Appalachian Mountains). In central Washington and Oregon, it most often is found
in mixed stands of conifers containing Douglas-fir and western hemlock.
Commercially Important Habitats
|Although matsutake occurs and is commercially collected throughout much of the
coniferous forest zone of North America, certain areas are especially productive and
heavily harvested. We are most familiar with commercial harvesting in the Pacific
Northwest United States but include general habitat descriptions for areas of
commercial harvesting in Canada and Mexico as well. Harvesters are secretive about
where they collect, and new areas of profitable matsutake harvesting are still being
discovered. This section reflects our current knowledge but is subject to change as
new areas become widely known, harvesters shift their activities, and public land
managers become aware of the trends.
|The American matsutake fruits abundantly in the coniferous forests of Canada.
British Columbia currently experiences the largest harvest, where fruiting occurs
in at least 10 biogeoclimatic zones (de Geus 1995a, Meidinger and Pojar 1991).
Figure 3 illustrates areas of known harvesting. It was compiled through consultation
with forest district staff and from discussions among industry participants at a series
of public meetings (de Geus and others 1992, de Geus 1995b). Commercial
harvesting in this province is favored by relative proximity to Japanese markets and a
harvest season that starts early and lasts for several months as fruiting progresses
from north to south, high to low elevation, and inland to coastal areas.
The American matsutake also fruits across Canada in northern Alberta,
Saskatchewan, Manitoba, Ontario, and Quebec. In Quebec and Ontario, it is especially
associated with jack pine forests growing on long mounds of well-drained glacial till
called eskers (Miron 1994). In this zone, matsutake fruits in August and September as trees
become dormant in response to shortening photoperiods. The season can be brief,
because killing frosts soon follow. Although crops can be huge, the commercial
harvest is only beginning to grow as the industry learns to cope with the short
season, large areas of un-roaded habitat, a limited transportation infrastructure,
and a small labor force.
United States Habitats
|Figure 4 shows areas in the Pacific Northwest were matsutake fruits
consistently and commercial harvesting is
concentrated. In Washington State, the American matsutake is harvested commercially on the Olympic Peninsula near Shelton and
on both sides of Stevens Pass in the Cascade Range south to the Columbia River.
Soils near Shelton and in central Washington are derived from well-drained glacial
tills and, at higher elevations in the Cascade Range, consist of tephra deposits from
Mount Rainier, Mount Adams, and Mount St. Helens. Matsutake typically fruits from
300 to 1200 meters in elevation in a variety of forest types, including:
• Douglas-fir, western hemlock, salal, sword-fern—Near Shelton on the Olympic
Peninsula and in the valleys of the western slopes of the Cascade Range, the
forest stands are typically composed of Douglas-fir, western hemlock, and
western red cedar with salal and sword-fern in the understory.
• Mixed conifer/ericaceous shrubs—At higher elevations, on both east and west
slopes of the Cascade Range, other trees intermingle with Douglas-fir and western
hemlock to create mixed-conifer stands; the predominant species are Pacific silver
fir, noble fir, grand fir, lodgepole pine, western white pine, and ponderosa pine.
These forests often have ericacious shrubs in their understory. In all these habitat
types, the candy stick plant is common where matsutake fruits (Plate
9). The sand dunes of the central Oregon coast contain three major habitat types where
matsutake consistently fruits.
• Shore pine/hairy manzanita/kinnikinnic—This habitat type is found on dry, naturally
stabilized dune landforms. The dominant tree in these areas is shore pine, 35 to
80 years old, with younger pines colonizing along the perimeter of the stand. Brush
understory is composed of hairy manzanita and kinnikinnic with patches of
evergreen huckleberry, and Pacific rhododendron. Herbaceous ground cover is
generally lacking, with occasional candy stick and pinesap plants scattered
through out. The abundance and diversity of lichens is conspicuous. Duff and litter layers
may be absent or up to 8 centimeters deep. Some areas contain a well-developed
moss layer up to 20 centimeters deep. Elevation ranges from 3 to 100 meters.
Slope and aspect vary.
• Shore pine/evergreen huckleberry—This habitat type is found on higher portions of
naturally stabilized dune landforms. Arboreal overstory vegetation consists of shore
pine, 35 to 80 years old, with some Sitka spruce and western hemlock beginning to
colonize. Brush understory may be moderate to dense, composed of predominately
evergreen huckleberry, salal, and Pacific rhododendron. Herbaceous ground cover
is generally lacking with occasional candy stick and gnome-plant present. Duff and
litter layers usually range from 2 to 8 centimeters deep with moss growing in open
areas. Elevation ranges from 10 to 100 meters. Slope and aspect vary (Plate
(American matsutake also fruits in similar habitat on the coast of northern
California near Eureka.)
• Shore pine plantations—This habitat type is found on dry dunes stabilized
through management actions. Almost all plantations where matsutake fruits are at Feast
35 years old. The shore pines have an understory of Scot's broom and remnant
patches of European beach grass. Several native species have begun to colonize
the now stabilized dune area including Sitka spruce, evergreen huckleberry, pearly
everlasting, yarrow, and kinnikinnic. Candy stick is present in older plantations.
Duff and litter layers are typically 5 to 10 centimeters deep. Many areas contain
well-developed moss layers. Elevation ranges from 3 to 100 meters. Slope and
Three general habitat types occur in the southern Cascade Range where matsutake
consistently fruits. Large quantities are regularly harvested from the Diamond Lake
Ranger District of the Umpqua National Forest, the Crescent Ranger District of the
Deschutes National Forest, the Chemult Ranger District of the Winema National
Forest, the Goosenest Ranger District of the Klamath National Forest, and the
McCloud Ranger District of the Shasta-Trinity National Forest.
• Mixed conifer/snowbrush, manzanita—The presence of Shasta red fir (an important
matsutake host) distinguishes this habitat from the mixed-conifer habitat in the
Washington Cascade Range. Shasta red fir grows in association with Pacific silver
fir, white fir, and mountain hemlock on the eastern to northern aspects and at
higher elevations. On southern or western exposures and at lower elevations it
grows with sugar pine and ponderosa pine. Snowbrush and green-leaf manzanita
dominate on the southern exposures or in disturbed areas. Creeping snowberry
and mahala mat are common in mesic areas, whereas bitterbrush and sage species prevail at lower elevations or in xeric environments. Phacelia species,
goldenweed, strawberry, western needlegrass, Ross's sedge, and bottlebrush
squirreltail are common herbaceous associates. As this habitat grades into
northern California (as far south as the area around Mount Shasta) ponderosa
pine, white fir, and incense-cedar become more common. The sparse forest floor
vegetation often includes dusky horkelia, western prince's pine, little prince's pine,
mountain sweetcicily, white hawkweed, and heart-leafed arnica. Soils are air-laid
pumice over lava colluvium, cinders, and tuff. Organic litter layers average 2 to
12 centimeters deep. Elevation ranges from 1350 to 1650 meters in the north
and 1450 to 1850 meters in the south (Plate
• Lodgepole pine/bitterbrush/needlegrass—The dominant overstory is lodgepole
pine, 60 to 120 years old. Brush understory is predominately bitterbrush with
rabbitbrush, needlegrass, and sedges less common. This habitat type is found
on coarse sand to loamy sand or pumice soils. Litter averages 2 to 8 centimeters
deep. Elevation ranges from 1600 to 2000 meters. Slope position is generally flat
or concave (Plate 12).
• Lodgepole pine/manzanita—Lodgepole pine is the predominant species
with Shasta red fir, white fir, or white pine
present depending on slope position. The common understory species are pinemat
manzanita, green-leaf manzanita, and
western needlegrass, with some scattered bitterbrush. The soils consist of air-laid
pumice and loamy coarse sand. Litter layers range from 2 to 8 centimeters deep.
Elevation ranges from 1550 to 1850 meters. Slope position is generally flat or
The Klamath Mountains of southwestern Oregon and northern California contain
three habitat types where matsutake consistently fruits.
• Tanoak, Douglas-fir, madrone/huckleberry, rhododendron—This habitat type
is found in closed-canopy tanoak stands (50 to 150 years old) with scattered
Douglas-fir, madrone, and knobcone pine. Brush understory often consists of
evergreen huckleberry, manzanita, and Pacific rhododendron. Herbaceous ground cover is generally lacking and fruiting occurs in a duff layer of hardwood
leaves 2 to 12 centimeters deep. Soils are derived from schists, conglomerates,
metasediments, and sandstones. Elevation ranges from 300 to 800 meters. Slope
and aspect vary but ridges and south to southeast exposures are most productive.
Matsutake fruits in this habitat in Oregon between the Windchuck and Rogue
River drainages in a band 15 to 40 kilometers inland from the Pacific Ocean. In
California, it fruits in this habitat on the Hupa Indian Reservation; in the Orleans,
Gasquet, and Lower Trinity Ranger Districts of the Six Rivers National Forest; and
further south in the King Range National Conservation Area to at least
• Tanoak, Douglas-fir, golden chinkapin/Oregon grape, poison oak—This habitat
type is found in closed-canopy tanoak stands (50 to 150 years old) with
Douglasfir, golden chinkapin, madrone, and sugar pine scattered in the
overstory. The understory vegetation typically consists of smaller tanoak, golden
chinkapin, and madrone, in addition to canyon live oak, white fir, poison oak, and vine maple.
Herbaceous ground cover is generally light and contains dwarf Oregon grape,
salal, twinflower, candy stick, and sword-fern. Matsutake fruits in a duff layer of
hardwood leaves 2 to 12 centimeters deep. Soils are derived from
metasediments, metavolcanic, igneous intrusive, and granitic parent materials. Elevation ranges
from 550 to 900 meters, slope and aspect are variable, but ridges and north to
northeast exposures have the most consistent production. In Oregon, matsutake
fruits in this habitat in the Illinois Valley west from the Elk Creek drainage and
east to the Deer Creek drainage. Isolated fruiting occurs in the Applegate River
watershed in similar habitats. In California, fruiting occurs in portions of the
Ukonom and Happy Camp Ranger Districts of the Klamath National Forest, along the Klamath River from the mouth of the Salmon River north to Indian
Creek, and along the Salmon River from the mouth upstream to the Forks of the Salmon
• Douglas-fir, canyon live oak/poison oak, red bud/hairy honeysuckle—Canopy
layers range from predominately canyon live oak to a mix of live oak and
Douglas fir. Madrone and California black oak are typical hardwood associates. Common
shrubs are poison oak, California red bud, and hairy honeysuckle. Soils are shallow
to deep, well drained, and derived mostly from shists and metasediments with
some igneous intrusives. Elevation ranges from 300 to 1050 meters. Although this
plant community is commonly associated with south and west aspects, matsutake
predominantly fruits where it occurs on east and north aspects that have steep
slopes and soils with high rock content. This habitat is common along the Klamath
River from the mouth of the Trinity River to Happy Camp and along the Salmon
River from the mouth upstream to the Forks of the Salmon.
|The distribution and harvest of the American matsutake in Mexico is limited to
temperate mountain forests at relatively high elevations (greater than 1500-2000
meters). These forests are biologically diverse; Mexico has more pine species than any
other country. The American matsutake likely grows in association with various tree
species, especially pine, fir, and evergreen oaks. The taxonomic identity of
mushrooms collected as matsutake in Mexico is unclear; some specialists feel there
are distinct species or ecotypes in Mexico and, given the diversity of habitats and
arboreal associates in Mexico, this is possible (Plate
14). Affinities of Mexican
ecotypes or species with Eurasian and other North American species still need
study; genetic analyses will be revealing. The range of locations (Fig. 5) where
matsutake is harvested coincides fairly closely with the distribution of the teocote
pine, a matsutake host (Plate
15). Commercial harvesting has occurred since 1985,
principally in the States of Hidalgo, Mexico, Michoacan, Pueblo, and Veracruz
(Villarreal and Perez-Moreno 1989). Although matsutake frequently fruits in remote
areas with rugged topography, harvesters and mushroom companies are developing
the means to quickly transport the mushrooms to their markets in Japan, thereby
expanding their activities in Mexico. The fruiting season in Mexico is early; it ranges
from late July through October, depending on the specific locale and elevation. The
southernmost extent of the range of the American matsutake is still unclear. Some
harvesters are currently bio prospecting for new populations in Chiapas, Mexico,
and in Guatemala.
A Case Study of Shiro Ecology in Central
|In autumn 1985, Hosford and Ohara (1986, 1990, 1995) began the first
matsutake shiro studies in North America in central Washington. Using the basic approach
of Japanese investigators, they mapped shiros and characterized the topography,
climate, soil type and vegetation. Each year, from late August through mid-November,
each site was monitored one to three times per week for appearance of matsutake
and other mushrooms. Matsutake were counted and their position in the shiro marked
by flags color coded by year. From these markings, the relative position of mycelia
and host roots (mycorrhizae) were determined and annual growth mapped. Soil
temperature and moisture, fungal species, bacteria populations, and other biotic
factors also have been examined.
| No. of shiros
|1 = Lake Kachess
|| 0 (2)
2 = Salmon La Sac
3 = Fish Lake
|| 3 (4)
4 = Howson Creek )
|| 3 (3
Total shiros 9(19)
|Nineteen shiros were identified and mapped at four sites
(Fig. 6). Subsequent
logging on private forests reduced the study to nine shiros on three sites. The sites
occur in warm, moderately dry forest, on the east slope of the Cascade Range on
both private and public land. The shiros were found on gentle, southwest-facing
slopes and benches between 700 and 900 meters elevation. Summers are hot and dry, and most precipitation occurs between November and April as snow. The
fruiting period for matsutake is relatively short, usually 2 to 3 weeks, and coincides
with increasing rainfall from October through early November.
The study sites occur in several forest types—lodgepole pine (site 3), grand
fir (site 2), and western hemlock (sites 1 and 4) that range from relatively dry to wet,
respectively. All sites, except for site 4 (a climax stand), are mid- to
from 80 to 200 years old. Grand fir is a minor overstory species at all four sites but
common in the understory. Douglas-fir is present at all sites, dominant at sites 1-3,
and co-dominant with western hemlock at site 4.
Shrub and surface vegetation is generally sparse in
shiros. In the most productive shiros, vine maple and several ericaceous plants often are present. These plants
and several other species, especially those in the Caprifoliaceae, were used as
indicators for locating new shiros. In addition, the ectomycorrhizal fungi
Tricholoma zeileri, Gomphidius, Suillus, Cantharellus subalbidus
(the white chanterelle), and
Rhizopogon parksii were found in or near shiros at the time of matsutake fruiting.
Table 1 lists plant and fungus species documented at these research sites.
|Table 1—Plant and fungal species typically found in an
Abies grandis/Acer circinatumf
Chimaphila umbellata/Tricholoma magnivelare forest association in central Washington
|Tree overstory layer:
|Abies grandis*+ latifolia
|Pinus contorta v.
|Tree understory layer:
||(= Tricholoma focale?)
|Shrubs and subshrubs:
||Russula (emetica complex)
|Rosa woodsia v. ultramontan
|" * = indicator species; + = suspected mycorrhizal
host.Source: Hosford and Ohara 1990.
|Soils are typically
spodosols, originate from glacially deposited parent material,
have less than 25 percent organic matter,
and are thin, sandy and well drained. In profile they have a shallow, but distinct, ashy E-horizon and a reddish B-horizon enriched
with iron and organic matter. A relatively thin duff layer, 0.5 to 4 centimeters thick,
overlies the E-horizon (Fig.
Mushroom primordia developed in the ashy E-horizon, whereas the
ectomycorrhizae developed below, in the transitional grayish-brown EB-horizon. Development from
primordia initiation to fully opened specimens took about 10 to 20 days depending on
soil temperature and moisture. As the primordia absorbed moisture they expanded
upward through the ashy E-layer. Fully expanded mature specimens often just barely
reached or broke through the duff layer, so lateral spore dissemination was restricted
|American matsutake fruited more abundantly in mixed stands of Douglas-fir and
western hemlock (for example, site 4) than in other forest types. Although density
of fruiting was relatively high, distribution of the mushrooms was unevenly scattered.
This is similar to the Japanese matsutake in mixed stands of northern Japanese
hemlock (Ohara 1981). Perfect mycelial rings were uncommon and the shape of the
ring often appeared fragmented or as separated arcs (Fig.
8). When the fragments or arcs were connected by lines, the shiro typically took the shape of a semicircle.
Figure 9 shows the profile of a shiro that had a diameter of about 6 meters and
expanded about 4 centimeters per year on average. The physiologically active
mycorrhizal zone (AMZ) (11-111) was relatively wide and deep with abundant blackish,
branched mycorrhizae. The ectomycorrhizae examined were structurally similar to
those formed by the Japanese matsutake in that they lacked well-defined Hartig nets.
The epidermis was sloughed when infected by the fungus and the hyphae invaded
the intercellular spaces of the root cortex. Preliminary studies also indicated that the
AMZ had a simplified bacterial flora similar to that of the Japanese matsutake
shiro. The boundary between the decaying mycorrhizae and decayed
mycorrhizae, zones IV and V, could not be visibly distinguished.
|Each study site and all shiros were monitored one to three times per week from
September to November 15. Mushrooms were marked and recorded, but for uniformity, only counts from the two most productive shiros per site are presented for
comparison. Ambient temperature and precipitation data, recorded as monthly
averages and accumulative values, respectively, were obtained from a nearby
weather station at Lake Cle Elum.
| Considerable disagreement exists about the trophic
character of the matsutake fungus. Various
researchers have reported characteristics of saprobic, parasitic, and mycorrhizal
fungi. Aggressively invasive hyphae and a weakly developed mantle are cited as evidence that species of matsutake fungi
may be somewhat parasitic. Other researchers have been unable to substantiate these claims; rather they find typical
mycorrhiza morphologies. Likely these discrepancies are the result of examining mycorrhizae in various stages of infection
and senescence. That matsutake fungi may vary on a spectrum of mutualism to parasitism (Johnson and others, in
press) is certainly possible. Likewise, many mycorrhizal fungi have some saprobic
(decompositional) abilities, and often
these abilities are enhanced by surplus carbohydrates the fungus obtains from its photosynthetic plant host
and others 1994, Miller 1995). The dense mycelial mat of the matsutake shiro suggests that it may be capable
of aggressively weathering mineral soil through organic acid exudates that alter soil chemistry and shift microbial
populations (Griffiths and Caldwell 1992).
|Figures 10 through 13 compare the
sites over four seasons. Cumulatively, Site 1(Lake Kachess, western
hemlock site) was the most productive, producing 48 mushrooms. Site 2 (Salmon La Sac, grand fir site) and site 3 (Fish Lake, lodge pole pine
site) each produced 32. Site 4 (Howson Creek, western hemlock/Douglas-fir site)
produced 37. Higher production at Lake Kachess and Howson Creek (sites 1 and 4)
may have been related to slightly wetter and warmer conditions, as indicated by the
relative abundance of western hemlock. Both sites also have an understory of vine
maple and a variety of ericaceous plants, which seem to be associated with shiros in
this area. The Salmon La Sac and Fish Lake sites (sites 2 and 3), on the other hand,
are higher in elevation and drier. Both contain lodgepole pine, western larch, and a
sparse ground cover of species such as Oregon grape.
On a combined yearly basis (sites 1 through 3 only), 1988 production was the
highest with 51 mushrooms over 18 days; 19B5 was second with 39 over 18 days:
1986 was third with 22 (zero at site 3) over 11 days; and 1&87 had none (note: these
figures represent counts from only two of the most productive shiros at each site).
Differences in seasonal length and production are related directly to' rainfall and
temperature. In 1985, 1986. and 1988, fruiting occurred when accumulative
rainfall reached 14 centimeters and continued until accumulation reached 35 centimeters or
more. At the same time, average temperatures were mild and above 5 "C. In 1&87,
a year of no mushroom production, temperatures were mild and above 5 °C through
mid-November, but only 16 centimeters of rain fell during the same period. A pattern
similar to 1987 has occurred several times since; these were some of the driest and
warmest years recorded in the area.
|In spring 1995, we began daily monitoring of soil temperature at site 4
(Howson Creek). In future years, soil moisture will be monitored weekly from mid-August
through November. Measurement of mycelial and mushroom growth and productivity will continue at Howson Creek only. Meanwhile, we will follow fungal and
plant succession at Lake Kachess (site 1), which was logged in 1992. Dr. Ohara
will analyze soil microbes in the AMZ and examine mycorrhizae. Spore germination
and cultural studies of American matsutake will be conducted in cooperation with
colleagues. From additional ecological data we hope to refine our geographic
information system (GIS) map of potential matsutake habitats in the Wenatchee