Many California Indian tribes utilized mushrooms for food, medicine, and/or technological purposes. This paper summarizes which mushrooms were important to different California Indian tribes in historic and modern times and how they were harvested, prepared, and stored. Oral interviews were conducted and the ethnographic literature reviewed to detail the extent and complexity of indigenous knowledge about fungi harvesting and associated burning to enhance mushroom populations and their habitats. Through two case studies, we review indigenous burning practices of several tribes in the lower montane mixed conifer forests of the central and southern Sierra Nevada, and the mixed evergreen forests of northern California. We explore the potential ecological effects of burning on these forests at different levels of biological organization and conclude by offering suggestions for research, management, and restoration practices needed to perpetuate usable mushrooms.
In parts of California at European contact, different kinds of fungi provided important contributions to native people's existence, serving as food, medicine, tinder, and dyes. Native Americans harvested these useful fungi from a variety of habitats: coastal prairies, chaparral, mixed conifer and hardwood forests, and montane meadows. Tribal harvesters primarily collected the spore-containing fruiting body or sporocarp of some fungi, those commonly referred to as mushrooms. Varieties included chanterelles, morels, boletes, common field, and other soil-growing mushrooms. Other types, such as willow or oyster mushrooms and giant sawtooths, were cut or torn from the trunks or branches of live and dead trees.
California Indians were intimately familiar with the color, shape, texture, and smell of a diversity of fungal species and knew in which habitats they grew, on what substrates to find them, and which mushrooms have special relationships with different kinds of shrubs and trees. Tribal mushroom harvesters understood how maturation times varied according to elevation, substrate, weather patterns, and microclimatic differences. Today some California Indians still harvest mushrooms, often gathering them in ways that —they assert— ensure plentiful harvests over the long term: acting as dispersal agents, using appropriate gathering tools, being careful to leave some for spore production, and burning areas to encourage mushroom numbers and densities and maintain fungal habitat.
This article begins by reviewing the different kinds of mushrooms, where they are found and their uses in California Indian cultures, and how they were dried, stored, and prepared in historic and modern times. It explores fungi's ecological roles in different ecosystems and how Native Americans may have influenced their abundance, densities, diversity, and habitat quality with harvesting techniques and burning within two forest types— the lower montane forests of the Sierra Nevada and the mixed evergreen forests of northern California. Our findings are analyzed within a broader context of discussions with western mycologists and fire ecologists and the relevant scientific literature to explore the potential effects of indigenous management practices on forest ecosystems. Lastly, we discuss needed research in California and the ways researchers and managers might integrate indigenous harvest and management of useful mushrooms into ecological restoration projects and adaptive management plans. Reintroduction of these techniques may be key for not only the conservation of mushrooms, but also enhancing the health of certain ecosystems today, via the ecological services fungi provide.
Importance of Fungi to Ecosystem Health
Fungi form an important component of different ecosystems, serving as food for a great variety of organisms, enhancing soil structure through mycelia, and having an important role in the breakdown of dead plant and animal remains. Certain fungi maintain natural ecosystems through mutualistic mycorrhizal relationships with plants (Kaul 2002). The vegetative part of the fungus, the part that gets its nourishment and endures from year to year, is hidden underground as a vast network of interwoven threads known as mycelia. This network emanates from the fruiting body in all directions and surrounds and penetrates the roots of individual host trees or shrubs. The fungus's mycelia take up and transport mineral nutrients and water to the plant from the soil in exchange for carbon and simple sugars that move from the plant roots to the fungus (Allen 1991). The nutrient exchange structure, where the fungus grows around and within fine root tips, is called a mycorrhiza. Not only are mycorrhizal mutualisms widespread, but because the mycorrhizal fungal hyphae connect individual plants, the symbiosis acts as an integrator of plant communities (Allen 1991:39–40). Read (1990) would go so far as to conclude that the nutrient dynamics of terrestrial ecosystems can be understood only in terms of the activities of their mycorrhizal fungi.
Many kinds of fungi native people gather have symbiotic relationships with shrubs and trees as mycorrhizal associations. There are two major types of mycorrhizae distinguished by morphological and physiological features: arbuscular mycorrhizae (AM) and ectomycorrhizae (ECM). Arbuscular mycorrhizae are associated with herbaceous species including most agricultural crops. In forested ecosystems AM have relationships with certain herbs, grasses, shrubs, hardwoods, and conifers (see Trappe 1962; Trappe, Molina et al. 2009). Most abundant and commonly collected edible forest fungi fruiting from soil/humus are ectomycorrhizal (David Pilz, Lake unpublished field notes 2010). Forest fungi that form macroscopic fruiting bodies can grow in soil or grow on wood. Only the soil-forming types can have mycorrhizae. Those that fruit above-ground are called epigeous, and those that fruit below-ground are called hypogeous. Examples of epigeous mushrooms include American matsutakes, chanterelles, and boletes (Molina et al. 1993; Molina et al. 2001; Trappe, Molina et al. 2009). Truffles are classified as hypogeous mushrooms (Trappe, Molina et al. 2009). Other fungi that do not form mycorrhizae are called saprotrophic fungi that derive food from decomposing logs, stumps, or other dead organic materials on the forest floor (Arora 1986). They perform vital functions by decomposing organic matter and enriching soils in the process. Without their role as decomposers, dead plant biomass would accumulate.
Methods employed in this ethnomycological study include a careful review of major published ethnographic descriptions, ethnobotanies, and unpublished university theses on each California Indian tribe, perused for four types of mushroom information: species harvested, harvest strategies, uses, and habitat management. United States Department of Agriculture-Forest Service (USDA-FS), Six Rivers National Forest Heritage Program and Karuk tribal reports were reviewed, and internet search engines were utilized to find tribal newsletters or related publications. These sources enabled us to do a key word search, focusing on the words “mushroom” and “fungus.” Additionally, the field notes that provide the basis for these published works often contain important information that was never published, and some of these notes, such as those of Frank J. Essene, John W. Hudson, and Frederick S. Hulse, were reviewed for relevant information. Many museums around the country funded expeditions or sponsored individuals to purchase artifacts to enrich their collections including mushrooms and plant parts used for food. Particularly valuable are the associated accession notes (Anderson 2005a). We summarized the mushroom information found in the California Indian collections of two museums, the Phoebe Apperson Hearst Museum of Anthropology at the University of California, Berkeley and the Oakland Museum of California.
Qualitative interviews were conducted with knowledgeable Native Americans from the Amah Mutsun (Ohlone), Big Pine Paiute, Central Sierra Me-Wuk (Miwok), Chukchansi/ Choinumni, Coast Miwok, Hupa, Karuk, Luiseño/Cupeño, Mono, Salinan, Southern Sierra Miwuk (Miwok), Tuolumne Band of Me-Wuk (Miwok), Washoe, and Yurok tribes between 1986 and 20121. In addition to interviews, some native consultants were taken to mixed conifer and mixed evergreen forests to directly identify mushrooms. Specimens for some mushroom species were gathered and sent to Michael Davis, a mushroom expert in the Department of Plant Pathology at University of California, Davis. In his laboratory, a small amount of tissue was taken from the specimen, frozen in liquid nitrogen, and treated with chemical agents to extract DNA. The laboratory then ran a PCR (polymerase chain reaction) using some DNA building blocks that are specific to mushrooms. Davis (personal communication 2011) explains, “The PCR simply amplifies a very tiny amount of DNA in the specimen to levels large enough to analyze in a DNA sequencer. Since every organism has a unique DNA fingerprint, we can identify the specimen by matching its sequences with those in a large DNA database.”
Fungus scientific names were updated using the database http://www.indexfungorum.org. Plant scientific names were updated using the PLANTS database http://plants.usda.gov and the new Jepson Manual (Baldwin et al. 2012). Mono name spellings for mushrooms are taken from Bethel et al. 1984.
Mushrooms Harvested: Their Uses, Preparation, and Storage Methods
Mushrooms played an important role in the traditional livelihoods of some California Indian tribes. In the Indian household, mushrooms provided food as well as a range of products (Table 1). In modern Indian households, mushrooms are still consumed, mainly as food.
Uses of fungi by California tribal groups. Descriptions come from the associated reference.
Documents record California Indian tribes' historic (and in some cases current) use of 26 species of mushrooms. Another 10 species are possible taxa, requiring the acquisition of specimens for verification. Together these 36 species span at least 19 fungal families: Agaricaceae, Amanitaceae, Auriculariaceae, Boletaceae, Cantharellaceae, Fomitopsidaceae, Gomphaceae, Helvellaceae, Hericiaceae, Hydnaceae, Hymenochaetaceae, Lyophyllaceae, Morchellaceae, Pezizaceae, Physalacriaceae, Pleurotaceae, Polyporaceae, Sparassidaceae, and Tricholomataceae. These include mushrooms that are contained in variously shaped fungi fruiting bodies (e.g., Amanita pantherina sensu Gonnermann & Rabenhorst, Aleuria aurantia (Pers.) Fuckel, and Hericium coralloides (Scop.) Pers.) and those that have spores borne inside a spore case or numerous lentil-like capsules —the puffballs (e.g., Calvatia sculpta (Harkn.) Lloyd and Calvatia gigantea (Batsch) Lloyd) (Burk 1983; McMillin 1956). Additionally, truffles were gathered by at least two tribes, but the species identifications are lacking (Table 1). Tribes in an area greater than two-thirds of the state gathered mushrooms, suggesting that this life form had widespread use (Figure 1).
Figure 1 likely underrepresents the number of California tribes that used mushrooms because when anthropologists asked about the plants Indians ate or used, few questions were directed towards the mushrooms they harvested. Mushrooms are poorly represented or absent from the majority of ethnographic descriptions of early California Indians, and when mentioned, mushrooms are infrequently identified to genus or species (see Table 1). For example, anthropologist Samuel Barrett (1952:93) jotted in his field notebook that the Pomo ate mushrooms, noting that there were “many” and that they were “excellent foods.” But he failed to record any species, saying, “no opportunity to identify these ‘right kinds’ presented itself.” There are probably a number of reasons for these slights or omissions. First, the science of mycology at the University of California, Berkeley (UCB), where most of the major anthropological studies of California Indian tribes were conducted, was not well developed during the most productive period of these investigations, between 1903 and 1975 (Heizer 1978). In 1939, Lee Bonar, a pioneer in California mycology, compared our knowledge of the state's mycota with that of its flora, emphasizing the overwhelming need for the systematic collection and study of fungi, and according to mycologist Peter Werner (2007), this is just as true today. An accessible (not technical) mushroom identification text for California was lacking until 1985 (Tom Bruns personal communication 2011). Second, mushrooms are highly seasonal and variable, dependent on certain kinds of ecological conditions, and unlike plants in a plant press, they spoil quickly when harvested. In historic times, it would have taken extra effort to collect specimens and identify them taxonomically before spoiling, given no rapid transportation or mailing services across many areas of the state. Third, there is a negative mystique around mushroom use, as the fear of being poisoned has kept many westerners from learning about their virtues. Fourth, there is also the popular, but mistaken notion, that mushrooms are empty calories offering little or no nutrition. Finally, mushrooms may not have been an important component in the diet, medicine chest, or technologies of some California Indian tribes.
Today native people of different tribes remember their families gathering mushrooms, but the specific scientific identifications are lacking. Given the sparse ethnographic research on the topic of mushrooms and lack of mushroom identifications in the literature, it is conceivable that many more species were gathered and utilized in various ways than what we describe and tally here. Hints of the significance of mushrooms in the traditional diet, for instance, are found embedded in cultural values and societal organization of certain tribes. For example, Sierra Miwok rituals were performed before the eating of the first crop of particular mushrooms (Barrett and Gifford 1933:164). The mention of edible mushrooms in tribal myths, such as among the Chilula, may also refer to their importance and possibly the antiquity of their use (Kroeber 1976:269).
Certain mushrooms that California Indians used and continue to use are an important source of biological active compounds of medicinal value, having antioxidant, antimicrobial, antitumor, and antimutagenic benefits (Barros et al. 2008; Grüter et al. 1990; Ko et al. 2005). They can boost the immune system, lower high blood pressure, and increase defenses against viral infections and cancer (Cheung 2008; Yang 2011), and particular mushrooms may have topical, in addition to internal, benefits. It is no wonder then, that some California Indians valued mushrooms for their healing properties. For example, cooked mushrooms and their broth were fed to the sick and elderly among the Mono as recalled by Norma Turner Behill, Mono/Dumna:
Up at Tamarack Flats there is a mushroom [possibly wood ear Auricularia auricula-judae (Bull.) Quél.] that grows on dead pines and firs. This mushroom is used for healing —boil it and drink the broth. One time I had blood poisoning. I soaked my leg in it and drank the broth. Naqa' is ‘ear’ in Mono. It can be used as a poultice on burns (Anderson unpublished field notes 2006).
The Yuki applied the spores of puffballs (Lycoperdon sp.) to dry up running sores (Chesnut 1974). In the 1940s, Lucy Young, Lassik, described how her tribe used puffballs medicinally when a woman was shot in the mouth with an arrow: “An uncle of the woman pulled out the arrow…. Sakatne'lŭc (puffballs, a fungus) were gathered, ground up into a powder, and rubbed into the wound. This stopped the bleeding” (Essene 1942:92). The Sierra Miwok made a decoction of the red-edged yellow tree mushroom, called elmayu (possibly Laetiporus sulphureus (Bull.) Murrill) and drank it as a cathartic and a cure for rheumatism. The mushroom was also used as a poultice (Barrett and Gifford 1933:164).
Mushrooms supplied the raw material for some native technologies. They played a role as tinder, especially the polypores which when ground up and added to a friction-fire generated coal, can extend its life (Storm 2004). For example, Sparkman (1908:233) recorded the Luiseño starting a fire with a fungus growing on the decayed wood of Engelmann oak (Quercus engelmanni Greene). Mushrooms also served as a medium for carrying fire. When moving, the Central Sierra Me-Wuk carried fire in a kind of punk, a mushroom procured from the dead stumps or exposed roots of oak trees. According to Mrs. L. Haslam (1911:11), “A small coal of fire inserted in this punk would keep for days if kept dry.”
The Karuk found the red-belted conk (Fomes hemitephrus (Berk.) Cooke) on conifer logs. The white underside of this fungus was peeled off and rubbed on buckskin to polish or smooth the skin. Fomitopsis cajanderi (P. Karst.) Kotl. & Pouzar was used in the same way (Schenck and Gifford 1952:377). A fungus on the California black oak (Quercus kelloggii Newberry) caused a gnarl which the Pomo cut off, hollowed with fire, and used for cups, bowls, and other housewares (Grace Hudson Museum Archives n.d. a). Many tribes used a mushroom (species unidentified) to make a brilliant red pigment mixed with water or grease for painting the face and body for dances and other events (Dixon 1905:167; Driver 1939:333; Heizer 1967a:214, 216). An Indian shaman encountered by V.K. Chesnut in 1902 in Mendocino County, used the leathery outer covering of a puffball (Lycoperdon sp.) to encase small pieces of stone, securely fastening them to a stick to make a rattling sound.
Mushrooms were likely an important part of the traditional cuisine of certain California tribes, yet they are probably the least known of all the terrestrial foods recorded by anthropologists (Table 1). Mushrooms were a dietary supplement in some tribes, but in others, such as among the Mono, they were much more substantial, having all the attributes of a staple food: they have important nutritional value; they can be gathered in large quantities; they dry and store well; and in many cases they occur in the same areas repeatedly, providing a predictable harvest. N. Turner Behill remembered as a child that her family gathered a lot of seexayu' (Lyophyllum decastes (Fr.) Singer): “After drying them we usually had two 25 pound flour sacks that would be filled.” Her family harvested the same amount of willow mushrooms each year (Anderson unpublished field notes 2006). Ron Goode, North Fork Mono, said: “Dad and Mom would gather three or four grocery bags half full of one kind of mushroom. They'd check the same crop several times and they might get several harvests in the same season. A season might last a month and a half. They gathered nine or ten different kinds of mushrooms” (Anderson unpublished field notes 2012). Mushrooms were often gathered while collecting other seasonally available foods. Mildred Nixon, Hupa, recalled: “…we were taught how to go out in the mountains to find food, different kinds of food and picked up acorns. … And then we always found mushrooms. And whatever we found out in the woods we brought it home and ate” (Lake 2007:570). Among the Karuk: “People used to gather huckleberries, mushrooms, and especially tanoak acorns [during the same outing]…” (USDA-FS 1983 Interview-353).
Harvesting, preparation and consumption of mushrooms by various California tribes ranged from yearly to seasonal to daily practices. For example, the daily diet of the Central Sierra Me-Wuk during the early historic period included manzanita berries, black mushrooms, quail, salmon, bulbs, and leafy greens (Maniery 1983:194). In southern California among the Luiseño, mushrooms provided an important food supplement (Bean and Shipek 1978:552).
Having such a hearty flavor, mushrooms are likened to meat. Born in 1871, Jennie Newlan, Owens Valley Paiute, told anthropologist Frank Essene (1936), “This edible plant [taw-po, a mushroom] grows anywhere, on tree trunks, and also [on the] ground, the older people gather these on pine tree trunks or under sage brush. It is gathered cleaned and boiled and salted and eaten. They say it has the flavor of the meat.” Today Central Sierra Me-Wuk elder Phyllis Montgomery says, “the willow [oyster] mushrooms [possibly Pleurotus cornucopiae (Paulet) Rolland formerly P. ostreatus] are like a steak —they're chewy” (Anderson unpublished field notes 2010). Generally, protein concentrations in mushrooms range from 1 to 4% of fresh weight, or about 10–45% of dry weight, a significant amount (Hobbs 1995:54–55). For the amount of crude protein they provide, mushrooms rank below animal meats but well above most other foods, including milk (Chang 2008). Additionally, mushroom protein contains all of the nine essential amino acids required by the body (Cheung 2008). They are high in fats, phosphorus, copper, iron, various trace elements, and such vitamins as B, D, K, thiamine, riboflavin, ascorbic acid, ergosterol, and niacin (Arora 1986; Barros et al. 2008; Cheung 2008).
Throughout the year, mushrooms provided an important accompaniment to acorn, venison, elk, fish, nuts, and other foods. For example, the Valley Maidu cooked mushrooms with fish (Voegelin 1942:180). The Central Sierra Me-Wuk “used a bowl mortar and pestle to pulverize deer meat to combine with the mushrooms. This meal was quite popular…” (Maniery 1983:192). The Central Sierra Me-Wuk and North Fork Mono mixed hazelnuts or pine nuts with mushrooms of various kinds (Aginsky 1943:455). The Nisenan Maidu dried ground mushrooms and tree fungi to flavor acorn soup in the winter (Beals 1933:351).
Traditionally, mushrooms were kept whole, sliced, or shredded and were cooked in various ways: baked on hot stones, roasted or broiled on live coals, or made into a mush by boiling (Barrett 1952; Castetter and Bell 1951; Foster 1944; Goodrich et al. 1980). Some mushrooms were also eaten raw. For example, the Pomo harvested the yellow morel called pi-ko'tci (Morchella crassipes Schwein. & Cooke) and ate it fresh as a confection, and it was reputed to be sweet (Grace Hudson Museum Archives n.d. b) —although, due to toxic compounds, the consumption of fresh, uncooked morels is not recommended as it may cause intestinal discomfort (Pilz et al. 2007:62). Certain mushrooms were poisonous if eaten uncooked, and special methods were employed to remove their toxicity. According to the Sierra Miwok, the red-edged yellow tree fungus (possibly Laetiporus sulphureus (Bull.) Murrill) was eaten only after boiling, squeezing, and salting because if eaten raw, could cause vomiting (Barrett and Gifford 1933:164).
Many tribes dried mushrooms for future use, placing them on rooftops in baskets in the sun, or by a campfire, strung on a string, or skewered on sticks (Anderson 2009; Beals 1933:351; Lake 2007; Maniery 1983:192). When dry, mushrooms were stored indoors in porous baskets or outdoors in structures similar to granaries (Duncan III 1964:21). Dried mushrooms were then pounded in bedrock mortars and added to soups or boiled in baskets with hot rocks (Duncan III 1964:21). For example, when the Southern Miwuk wanted to eat their dried shredded mushrooms they boiled and ate them with mineral salt or ground and cooked them as a soup (Godfrey 1941). In 1983, a Wailaki elder shared how she gathered American matsutake, also known as tanoak mushrooms (Tricholoma magnivelare (Peck) Redhead), each fall and either dried or canned them (USDA-FS 1983 Interview-359). These preservation techniques are still used by other northern California Indian tribes (Lake 2007; Richards 1997).
The staying power of mushrooms in Native American diets is remarkable. Mono families still gather, for example, fluted black elfin saddles (Helvella lacunosa Afzelius) and seexayu', also known as fried chicken mushrooms (Figure 2) (Anderson unpublished field notes 2008). The Karuk continue to gather golden chanterelles (Cantharellus cibarius Fr.), black trumpets (Craterellus cornucopioides Persoon), lion's mane (Hericium erinaceus (Bull.) Pers.), hedgehogs (Hydnum repandum L: Fr.), and oyster mushrooms (Lake 2007, unpublished field notes 2010, 2012), and the Yurok still gather golden chanterelles, hedgehogs, king boletes (Boletus edulis Bull.), and meadow mushrooms (Agaricus bisporus (J. E. Lange) Imbach) (Lake unpublished field notes 2010; Yurok Tribe Newsletter 2010). The Tuolumne Band of Me-Wuk still gather the coral mushroom (Ramaria violaceibrunnea (Marr & D. E. Stuntz) R. H. Petersen) under ponderosa pines (Pinus ponderosa Lawson & C. Lawson) and white firs (Abies concolor (Gordan & Glend.) Hildebr.) in the central Sierra Nevada mountains (Figure 3) (Phyllis Montgomery, Anderson unpublished field notes 2010).
Particularly important among the northwestern California tribes are the American matsutake, harvested predominately under tanoaks (Notholithocarpus densiflorus (Hook. & Arn.) Manos et al.); the coccora (Amanita calyptroderma G.F. Atk. & V.G. Ballen) among the Mono and Southern Sierra Miwuk found in association with ponderosa pines, sugar pines (Pinus lambertiana Douglas), and California black oaks; and the willow or oyster mushroom, growing from dead hardwoods, which is still gathered by many tribes.
Today, mushrooms are boiled or fried with garlic and onions and eaten with tortillas or they flavor soups, meats, and pastas. They are sautéed with butter and flour to make gravy over rice, or stir-fried with vegetables. They are still eaten with acorns. Melba Beecher, Mono, describes another modern way to eat them as a healthy snack food: “In the wintertime when you run out of nuts or raisins, you pull out the dried mushrooms and boil them and put salt on them or dip them in salsa and eat them while you watch T.V.” (Anderson unpublished field notes 2006).
Some contemporary mushroom harvesters have adopted uses of taxa not recorded as historically used by their tribal groups. Similar to non-tribal novice mycologists/collectors, tribal people today use field guides, attend mushroom fairs and workshops, and then try new types of mushrooms and culinary preparations (Lillian Rentz and Janet Morehead (sisters), Karuk, Lake unpublished field notes 2012). In these ways, the (neo-) traditional mycological knowledge of tribal communities is adaptive and responsive to the available mycological science, forest management, and recreational, subsistence, or commercial experiences of the general public.
Strategies of Mushroom Harvest
Many kinds of mushrooms, such as sorog (Neolentinus ponderosus (O.K. Mill.) Redhead & Ginns), appear in the same places year after year, arising from the surfaces of rotting wood, dead stumps, snags, or downed logs during the long process of decomposition. Other mushrooms arise from the ground and have long-term associations with trees, shrubs, and grasses (Douhan et al. 2005; Hynes et al. 2010; Plamboeck et al. 2007). Thus, many California Indians have special areas that they repeatedly visit (Anderson 2009; Richards and Creasy 1996). “These sites are hundreds of years old,” said N. Turner Behill, regarding mushroom gathering areas (Anderson unpublished field notes 2006). Tom Carsoner, Central Sierra Me-Wuk, described his mushroom gathering sites as “a garden” because “you always know where to go” (Anderson unpublished field notes 2010). Because some edible mushrooms resemble and can be confused with toxic varieties, the Pit River tribe (Ajumawi band) of northeastern California had family plots to which they regularly returned to harvest certain types (Buckskin and Benson 2005:91).
There are several indigenous harvesting strategies that were and still are practiced in California. These include: 1) use of specific harvest technologies; 2) moderating intensity of harvest by leaving some mushrooms (e.g., young buttons and old, rotten ones) and leaving the stems behind and covering them with soil, litter or duff, while being careful to leave “threads” (mycelium) under the ground undisturbed; and 3) dispersing some of the mushroom spores around the site and new locations.
Appropriate Harvest Technologies
Several tools were traditionally used for mushroom harvesting. The human hand was used for breaking off or twisting the mushroom out, while employing a stick to poke and uncover those mushrooms lightly draped with litter, was a precaution to ensure they were mushrooms and not snakes (Anderson 1993). Stone knives were used for cutting the stem of the mushroom. Scrapers were used for retrieving mushrooms growing on trees or downed wood, as Pauline Conner, North Fork Mono, described: “On the black oak tree there was this unusual yellow mushroom. You take a scraper and knock it off. Lily [Conner's mother] gathered it in the spring. It looked puffy and it was stuck on the tree. They could get long, one and one-half feet, and it was slick to the touch” (Anderson unpublished field notes 1991).
Contemporary tribal mushroom harvesters use knives, scissors, trowels, sticks, or hands to gather mushrooms. They recognize that shovels and rakes can be destructive and purposefully do not use them on particular mushrooms (Anderson 2009; Richards 1997). For example, the deep raking of humus, moss, and soil in search for buried mushroom buttons and immature fruit bodies (e.g., American matsutake) was and is generally discouraged. These unopened buttons have not yet formed spores and raking can damage the mycelium in the upper layers of the soil, affecting future harvests.
Intensity of Harvest
Certain practices based on tribal beliefs are adhered to when picking mushrooms. Individuals interviewed take primarily only the bigger mushrooms, allowing younger mushrooms to grow larger. N. Turner Behill instructed the gatherer in harvesting naqa': “Cut off the stem and only take the bigger ones” (Anderson unpublished field notes 2006). Marie Coho, Mono, said: “The willow mushrooms down here below North Fork are harvested now. You only pick the biggest one —usually the lowest layer and leave the other ones to grow bigger” (Anderson unpublished field notes 2006).
Indigenous gatherers also are instructed to spare some mushrooms for tomorrow and leave some for the other animals. Tillie Lewis Mono/Chukchansi said: “Don't take all the mushrooms —if you do you're not going to have any more” (Anderson unpublished field notes 2006). This strategy preserves the genetic diversity of the mushrooms by leaving some for spore activity. Each fruiting body produces millions of tiny spores that are spread by the wind, water, and animals. Spore dispersal is the major way for mushrooms to outcross, leading to high levels of genotypic diversity. Furthermore, this native practice is considerate of wildlife that also feed on the mushrooms. Over-mature mushrooms growing from the ground that are too woody, decaying, or full of insects or mollusks are left alone. They still provide spores that will germinate and thrive when the environmental conditions are suitable.
For mushrooms that are ready to pick, the cap and part of the stalk is removed and the remaining stem is re-covered with soil and duff or leaf litter so that “no one can see that you have been there” (Richards and Creasy 1996:368). Southern Sierra Miwuk mushroom gatherers are aware of the mycelium under the ground that their grandmothers said were important not to disturb (Anderson 1988). California Indians knew to protect the underground portion of the mushrooms, which in turn produces the aboveground edible fruiting body. All of these rules are remembered by indigenous mushroom harvesters and are still practiced by the Karuk, Mono, Southern Sierra Miwuk, Tuolumne Band of Me-Wuk, Washoe, Yokuts, and Yurok. LaVerne Glaze, Karuk/Yurok, said, “We were taught by my folks to cut them [American matsutake] off with a knife at the ground level and cover them up with the duff. They said to leave the ones that had flowered out —they were better left alone. Once they have really opened up they get buggy” (see Figure 4) (Anderson unpublished field notes 2005). M. Beecher, said that in harvesting cuyu' (Morchella elata Fr.), “[if] you leave the stem, next year it will probably be in the same place” (Anderson unpublished field notes 1992). T. Carsoner learned how to gather mushrooms from his Aunt Etta Fuller (Northern Sierra Me-Wuk) who was born in 1900: “If you don't take care of the mushrooms, they won't take care of you” (Anderson unpublished field notes 2010). Darrel Cruz, Hungalelei Washoe, was instructed by his elders to “snip them [mushrooms] at the base in order to leave the roots there” (Anderson unpublished field notes 2012). Mushrooms, such as the willow or oyster mushrooms, that grow on dead downed wood or snags must also be gathered with care. Lawrence Bill, Mono/Yokuts, learned how to judiciously gather willow or oyster mushrooms from his mother: “I watched my mother leave the stump of the mushroom behind” (Anderson unpublished field notes 2006).
According to N. Turner Behill: “The places where the mushrooms are thickest, are the places where we gather them. Gathering doesn't hurt them and I leave a little offering and say a little prayer” (Anderson unpublished field notes 2006). Studies confirm that the harvest of fungal fruiting bodies, without raking, does not negatively affect future harvests in the short-term and may even have a slight stimulating effect (Arora 1995; Egli et al. 2006; Norvell 1992). However, technique and tool used are extremely important. A study that compared different harvesting techniques of American matsutakes demonstrated that careful picking, with gentle rocking and pulling and minimal disturbance to the litter layer, was not detrimental to mushroom production during the initial ten years of mushroom harvest activity. On the other hand, one-time treatments in which the forest-floor litter layers were removed by heavy, deep raking and not replaced, appeared to be strongly detrimental, with the effects persisting for nine years (Luoma et al. 2006). However, no statistically-based monitoring information exists about the cumulative impacts of intensive and widespread commercial harvesting over longer periods (Pilz and Molina 2002).
Humans as Dispersal Agents
Many kinds of mammals are vectors of mushroom spores (Grove 2002; Maser et al. 1978; Schigel 2009). Humans incidentally disperse spores by carrying mushrooms to different harvesting areas or returning home with their harvest. The Concow Maidu, for example, dried mushrooms on milkweed fiber strings which they passed through the mushrooms and hung between bushes. The Nisenan Maidu skewered mushrooms on twigs on shrubs (Beals 1933). Anthropologist John Whitfield Duncan III (1964:21) described a typical camp as “surrounded by bushes heavily weighted down with drying fungi.” At least one tribe, the Karuk, deliberately spread the spores of various mushrooms as well. They scattered the rotten caps of American matsutake mushrooms downhill to lengthen the fruiting line (Richards 1997).
Complexity of Indigenous Knowledge about Mushroom Harvesting
Indigenous knowledge of mushroom gathering was an intricate system that took into account weather patterns, elevation, environmental site criteria, habitats, substrates, soil types, plant associations, wildlife, and ecological relationships. Tribal peoples likely learned which mushrooms were edible by observing wildlife consuming mushrooms. For instance, the Karuk tell of how they learned to eat particular mushrooms by watching deer forage (Richards 1997).
The ability to distinguish between edible and poisonous mushrooms by shape, color, smell, texture, and size was keen, as demonstrated by the indigenous use of Amanita calyptroderma and Agaricus silvicolae-similis Bohus & Locsmándi, both of which could be confused with the more deadly Amanitas that are similar in appearance. Mushroom color was sometimes an indicator of age as Ruby Pomona, North Fork Mono, points out: “No'ē is a mushroom that is yellow when it's young and orange when it's too old. You find it on black oak stumps or dead trees. The mushroom is in layers” (Anderson unpublished field notes 2006).
Tribal people describe different criteria and various methods for evaluating the suitability of habitats for where, when, and under what conditions different mushrooms are likely to be found. For example, physical clues are used, such as time since last precipitation, temperature, humidity, soil, slope, or aspect of terrain. They also utilize biological clues such as forest stand density, canopy cover, tree age or size, abundance and distribution of woody material, and duff/litter quality of the forest floor. Additionally, clues regarding ecological relationships were employed, such as the presence of particular wildlife, associations with certain plants, or severity or type of disturbance history at the site, such as time since last fire. One pattern that emerges regarding tribal peoples is that intergenerational knowledge about mushroom harvesting and use comes from collective site-specific geographic experiences.
Edible mushrooms were gathered year round, demonstrating native people's sophisticated knowledge of how meteorological and seasonal patterns (e.g., weather patterns and day length) are connected with different ripening times. The optimal season for many varieties was following fall and winter rains. Following fall precipitation, ground fruiting American matsutakes, white and golden chanterelles, coccoras, and boletes were harvested. Wood-fruiting sawtooths were harvested generally in the fall to early winter. The potential time of harvesting for most mushrooms may have extended throughout mild winters into the spring. For example, black trumpets and hedgehogs fruit from late winter to spring. Other mushrooms, such as black morels, fruit in the spring or early summer. However, the extent and relative abundance of morel patches are correlated with disturbances such as fires or soil pH (L. Glaze, Lake unpublished field notes 2010). Oyster mushrooms fruiting from decomposing wood are likely dependent on humidity and temperature regimes (Richards 1997), and could be harvested in the fall, spring, or summer. T. Lewis explains, “They [oyster or willow mushrooms] are harvested when the fog sets in —in October or November” (Anderson unpublished field notes 2006).
Similar to gathering plant foods, mushroom harvesting spurred Indians to pay attention to environmental cues, often gaining hints to mushroom ripening. According to Lorraine Cramer, Southern Sierra Miwuk/Mono Lake Paiute, a sure sign that the mushrooms are out is when the ferns start coming up (Anderson unpublished field notes 1986). Mary Spears, Southern Sierra Miwuk/Yokuts, learned from her grandmother that the mushrooms under the pines are ready when the black oaks are leafing out (Anderson unpublished field notes 1989). M. Beecher would agree: “It is time to go looking for toopO [Amanita calyptroderma] because the black oaks are leafing out” (Anderson unpublished field notes 2006). According to the Pit River tribe (Ajumawi band): “When the red bells, Johnny-jump-ups, and dogwood start to bloom, the mushroom hunts can begin” (Buckskin and Benson 2005:89). Among the Karuk, coral mushrooms (Ramaria sp.), called “grandmas,” generally precede the fruiting of American matsutake and are used as an indicator to gauge optimal time for harvesting (Richards 1997). According to T. Carsoner, “Mothers [inedible mushrooms identified as Collybia butyrea] are harbingers of the mushrooms to come —the most important of which are the helli [Amanita calyptroderma]” (Anderson unpublished field notes 2010).
Habitats and Substrates
California Indians gathered mushrooms from sea level to mountaintops, across diverse vegetation types: valley grasslands, montane meadows, chaparral, forests, and along streams. Within these habitats, useful mushrooms were found on a variety of soil types and live or dead plant tissues. Sometimes the same kinds of mushrooms were and continue to be harvested from different soil or wood substrates (Richards 1997). For example, American matsutake mushrooms are harvested both on shale soils and decomposed metamorphic-red clay soils in a similar geographic area, although those on shale soil are generally harvested earlier in the fall. A Karuk elder said: “You look for places where they [American matsutakes] are buried in red dirt [clay] or shale. Someplace where it is not real damp but where it doesn't dry out. They come in after it rains where the soil holds the moisture” (Richards 1997:7). Other factors correlated with mushroom abundance and harvest were stand composition and surface litter/duff (fuel load) which potentially affect soil pH. For example, according to T. Carsoner, his relatives “would gather helli in the spring. In the fall they would rake the acorns into a pile with a branch, then scratch for the acorns in the duff, pulling them out and leaving the duff behind. Where the rows of duff were —the mushrooms would be thick” (Anderson unpublished field notes 2010).
Other mushrooms are found only on dead trees, on the ground, or only in burned areas. According to N. Turner Behill: “Cuyu' is scattered —not together. Twenty-five or thirty are scattered in one area. They grow in meadows and under the sugar pines and cedars from 3000 to 7000 ft. by Huntington Lake. They come up good after a burn. After a burn we knew there were going to be a lot” (Anderson unpublished field notes 2006).
Because some kinds of mushrooms (saprotrophic) appeared on the same dead wood year after year, snags, downed logs, and rotting wood of oaks and conifers were left in place to provide a continuous food supply. For example, willow or oyster mushrooms will repeatedly fruit from rotting alder (Alnus sp.), tanoak or willow snags and logs until the decay is too advanced. According to T. Lewis: “The willow mushrooms are on old trees and logs. You leave the downed willows because that's where they grow” (Anderson unpublished field notes 2006). Lion's mane can be found growing from injured tissues (bark/wood interface) year after year at the same wound spot on the same hardwood tree (such as a tanoak), provided the local habitat conditions of the individual tree are maintained (Lake personal observation/harvesting with L. Glaze). Recent research on American matsutakes indicates that different factors affect mushroom abundance at spatial and temporal scales, ranging from the site to the forest stand and across the landscape, even regionally (Amaranthus et al. 2000). Tree and shrub composition, diameter, and height, as well as forest structure and canopy cover, are important indicators of where particular mushrooms will be located, and when (Lake 2007).
Indigenous people observed and monitored particular environmental or meteorological conditions such as precipitation and temperature (Lake 2007; Richards 1997). California Indians correlate the fall rains, coupled with dry/cold and warm/moist weather patterns with stimulation of mushroom fruiting (Paulides 2008; Richards 1997). Scientific studies substantiate these broad-level weather phenomena that directly affect soil or wood moisture and temperature properties, thus stimulating or suppressing fungal fruiting potential (Pilz and Molina 2002; Pinna et al. 2010). Tribal harvesters have accumulated intergenerational knowledge about particular locations, disturbances or growth conditions that foster or provide suitable habitat for various mushrooms (Buckskin and Benson 2005).
Indigenous people recognize that certain mushrooms are found only in association with specific kinds of trees, shrubs, or herbaceous plants (Table 2). For example, the Mono, recognizing that certain species of mushrooms occur in a relationship with specific species of trees, use the trees as an aid in the search for mushroom types. According to N. Turner Behill, “Cayaakē' [possibly Ramaria rasilispora Marr & D. E. Stuntz] grows under the pines. They are found under the pine needles; they make mounds. They are gathered in June and July between 4,000 and 7,000 ft.” while seexayu' “grows under buckeyes, white oaks, black oaks, and live oaks –not water oaks. It has a different little odor. They are gray on top and tannish underneath. Sometimes you find one or two and sometimes you find up to twelve under one oak” (Anderson unpublished field notes 2006).
Tribally used fungi, their host plants, and association.
Other mushrooms have fidelity to plant community seral stages or micro-site conditions. Tribal peoples sought particular seral stages or age classes of forest stands and shrub patches. A 74 year-old Karuk elder recalled that in the western Klamath Mountains: “Where the tanoak [trees] grow about 15 inches in diameter and it's damp and moist with decayed leaves, is where the tanoak mushrooms grow” (USDA-FS 1981, Interview-281). Additionally, other features of certain habitats are used to aid the search for mushrooms or fungi. For example, some mushroom species are used as indicators of the relative likelihood of finding target species.
Decline of Useful Mushroom Abundance and Habitat
Many California tribal mushroom harvesters report that edible and medicinal mushrooms are dwindling, in part because of the change in conditions of gathering sites with new land uses. M. Beecher recalls many areas in the central Sierra Nevada where she and her family used to gather toopO: “We used to look for mushrooms all through Meadow Lakes, Pine Ridge, and Bretz Mill Road. Now you bump into homes.” Other reasons for the decline of useful mushrooms can include: environmental pollution, fire suppression/exclusion, climate change, application of dung and artificial fertilizers, industrial timber management, native and exotic diseases and pests, road building, and compacted soils from trampling (Arnolds 1991; Egli et al. 2006; Pilz and Molina 2002). N. Turner Behill says that cayaakē' are less plentiful now because “people walk all over and stomp on the mushrooms” (Anderson unpublished field notes 1991). Several Southern Sierra Miwuk consultants mentioned that the pine mushroom (Amanita calyptroderma) is not as plentiful on the Yosemite Valley floor as it used to be years ago (Anderson 1988).
Perceived declines in abundance might also be due, in part, to increased competition in harvesting. Today, commercial and non-tribal harvesters cover the same areas as California Indian subsistence harvesters in search of morels, American matsutakes, chanterelles, and other highly prized edibles. They market the mushrooms locally, nationally, and internationally, or consume them for personal use. The mushrooms command a high price in grocery stores and are forming an important part of the new California fusion cuisine being used more and more frequently in gourmet restaurant recipes (Young and Viverito 1998). Tribal people consider some harvesting methods of these commercial harvesters inappropriate when raking, shoveling or other extensive disturbance to the duff/soil interface is employed (Richards 1997). L. Glaze discusses the recent fate of the American matsutakes:
All I know is that they were plentiful while [I was] growing up. There were sackfuls that we could can or dry. In recent times, there were so many commercial mushroom pickers from other places and you could see the decline after that. They were overharvesting. I've been to areas where some commercial pickers have been and they never put the duff back and they rake the area. The buttons are what they are looking for. They are found under tanoak leaves and rotted sticks (Anderson unpublished field notes 2005).
While mushroom decline can be linked with certain human practices such as raking, it is possible that other kinds of activities, such as indigenous burning or purposeful scattering of rotten caps, can enhance or foster edible mushrooms.
Indigenous Burning of Mushroom Habitat and Its Potential Ecological Effects
Fire affects the abundance and spatial and temporal availability of mushrooms. Those that fruit abundantly in burn sites are called pyrophilous, meaning “fire-loving” (Cooke 1958:363; Pilz et al. 2007), and include the morels (Morchella spp.), cup fungi (Peziza spp.), fried chicken mushrooms (Lyophyllum spp.), and elfin saddles (Helvella spp.) (Arora 1986; Greene et al. 2010). Amanita spp. and Boletus spp. have been found on charred soil (Baar et al. 1999; Trappe, Molina et al. 2009; Watling 1988). Many explanations have been offered for this affiliation, such as elimination of competition from higher plants, fire stimulation of pre-established mycelium in the forest floor, ash deposition, increased soil temperatures, and abiotic and biotic factors associated with the surface and subsurface soil layers, including nutrient and soil chemistry changes (Duchesne and Weber 1993; Pilz et al. 2007; Wicklow 1975:852; Zak and Wicklow 1980:1915). Fire may alter the habitat by reducing thick litter and duff (i.e., humus) layers, thus affecting mushroom fruiting emergence (Pilz et al. 2004). Additionally, moderate severity fires can result in opening up canopies and thinning forests which may reduce stress to host trees with mycorrhizal associations (Egli et al. 2010).
The abundance and spatial and seasonal availability of particular mushrooms are increased indirectly when fire kills or injures trees or shrubs, creating new sources of woody material (Olsson and Jonsson 2010). Fire-scorched bark, in which the cambium tissue was killed, provides pathways for saprotrophic mushroom spore colonization, potentially via insect inoculators. For example, hardwoods killed by fires become new substrate for oyster mushrooms under suitable microclimates and meteorological conditions. Additionally, microbes or insects which feed on colonized dead, woody material can facilitate the establishment of some mushrooms (Grove 2002; Schigel 2009).
Some California Indians observed the relationship between fire and mushroom abundance and visited areas that had been recently struck by lightning to harvest mushrooms that grew in the recently burned areas. Katie Apling, Southern Sierra Miwuk/Paiute, recalled: “Cry-baby mushrooms [taxonomic identification lacking] that are brown and shaped like teardrops come up after fires under bushes in the chaparral and manzanita” (Anderson unpublished field notes 1989). M. Spears remembered, “They picked mushrooms in burned areas. They were called ‘burnt ground mushrooms’ [taxonomic identification lacking]. They were very black when picked. They were the size of a pink bottom [taxonomic identification lacking] and gathered in the spring. Mom would fry them. They kind of tasted like charcoal” (Anderson unpublished field notes 1989). “You find white morels [Morchella deliciosa Fr.] in roads and after burns” said P. Montgomery (Anderson unpublished field notes 2010). Rosalie Bethel, North Fork Mono, said: “When there was lightning, we let it burn. After the burn there were all kinds of mushrooms that grow better in forest areas under ponderosa pines, sugar pines, firs, and sequoias. I used to gather them after a fire” (Anderson unpublished field notes 1989).
While some species of fungi likely evolved with lightning fires before human habitation, some California Indian tribes set fires in areas to foster the growth of certain types of mushrooms. Some Indians assert that burning of areas may heighten numbers, densities, size, and diversity of useful mushrooms. Individuals of the Foothill Maidu and Foothill Nisenan, for example, told anthropologist Erminie Voegelin (1942:176) that the “ground [was] burned for [a] better crop” of mushrooms.
Indigenous Management of Mushrooms and Their Habitats
Two case studies are presented here which provide ethnographic evidence that tribes managed specific mushrooms and habitats within two forest types: the lower montane mixed conifer forests of the Sierra Nevada and the mixed evergreen forests of northern California. These are followed by a discussion of the potential ecological effects in these ecosystems from a western scientific perspective.
Case Study 1: Lower Montane Mixed Conifer Forests of the Central and Southern Sierra Nevada
The lower montane mixed conifer forests of the central and southern Sierra Nevada form a distinct belt spanning an elevation of 1200–2400 m. Ponderosa pine dominates the more xeric sites, while white fir is found on more mesic sites (Rundel et al. 1988). Within these forests, stands of chaparral, streamside forests, meadows, and seeps occur (van Wagtendonk and Fites-Kaufman 2006). Early reports comment on the openness of these forests in many areas, featuring large-diameter trees, 12–18 m apart, and an absence of underbrush (Reynolds 1959). Other tree species include giant sequoia (Sequoiadendron giganteum (Lindl.) J. Buchholz), sugar pine, incense cedar (Calocedrus decurrens (Torr.) Florin), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) and a major hardwood, California black oak. Both ponderosa pine and black oak are well adapted to light, regular surface fires and are intolerant of deep shade. Black oak needs bare mineral soil to germinate. While it is currently difficult to distinguish tree fire scars caused by lightning fires from those started by indigenous people in this region, some fire ecologists still assume that ignitions by native people were important but varied over the range of inhabited landscapes (Stephens et al. 2007; Swetnam et al. 2009; van Wagtendonk and Cayan 2008). However, indigenous burning in these forests is well documented in the historical literature and through oral interviews with California Indians (Anderson 1993; Baxley 1865; Clark 1894; Gordon-Cummings 1883).
For example, the Central Sierra Me-Wuk and other tribes in the Sierra Nevada mountains would “burn off large sections of the land. This kept the brush down, and consequently helped the Indian hunter working in a communal hunt” (Chisum 1967:203). Through oral interviews with Native Americans and non-Indians with long-term ties to the land, Anderson (1993) documented burning for at least ten reasons. These include reducing plant diseases, opening up the underbrush, and creating better habitats for useful plants and animals, but most important for this paper, they also deliberately burned areas to increase different kinds of mushrooms.
With regard to burning for mushrooms, the Mono and Tuolumne Band of Me-Wuk burned to stimulate the growth and abundance of at least four kinds in the forests including Amanita calyptroderma, Morchella elata, Peziza sylvestris and Ramaria sp. Eleven elders substantiate burning for mushrooms. All of these fungi have mycorrhizal relationships with hardwoods and/or conifers (Table 2). Common reasons for burning for fungi include enhancing size of the mushroom at the organism level, increasing numbers at the population level, and reducing the build-up of duff while leaving the mycelium intact, and keeping areas open to foster habitat for mushrooms at the community level. M. Beecher recalled: “They'd burn under the black oaks for better mushrooms in October, November, and December. The mushrooms that come up better are cayaakē' [Ramaria sp.], naqa' [possibly Peziza sylvestris], and toopO” (Anderson unpublished field notes 1991). “Cuyu comes up better after a fire too,” said Lydia Beecher, Mono (Anderson unpublished field notes 1991).
Dave and Ed Bowman, Wobonuch Mono, remembered burning to foster a diversity of mushrooms in what is now Sequoia National Forest in the Sierra Nevada:
Our dad said the Indians used to burn in the mountains every year. When they go up to the mountains to pick those black oak acorns, they'd camp up there and before the winter set in they'd burn the grass and they'd do this year after year, about October, November. They burned the areas where they hunted for acorns. It's not like it is now. Now it's so brushy, if it caught fire everything would go up in smoke. They'd burn it every year to keep it open. When they'd go back the following season they'd have all kinds of mushrooms up there, like the cones which are all wrinkly [Morchella elata] —others look like elephants' ears [scientific identification lacking]. That's how come they burnt every year. The mushrooms grow under the pine trees and under the black oaks. They've got two, three, four different kinds. They burned in the same spots where they camped every year. They followed this acorn route, picking acorns here and there. They went all over for the black oaks (Anderson unpublished field notes 1991).
Fire may also affect the size of the mushrooms. A North Fork Mono elder, Nellie Williams, recalled that: “When they'd burn, they'd really get big mushrooms” (Anderson unpublished field notes 1991). Ruby Cordero, Chukchansi/Me-Wuk, said: “Areas that had been burned they would go to. It fertilized the areas. The mushrooms would come back bigger and more of them. We used to dry mushrooms, and in the winter we'd cook them and then they'd be like fresh” (Anderson unpublished field notes 1991). Dan McSwain, North Fork Mono, explained the effects of the fires this way: “A lot of things grow a lot better when they burn in the fall. It's like fertilizer. The mushrooms up in the higher mountains grow better, like cuyu'” (Anderson unpublished field notes 1991). Burning may affect mushrooms positively by reducing dense litter that would block mushroom emergence. According to Francys Sherman, North Fork Mono: “I went to Yosemite in May, and those mushrooms that grow under the ponderosa pines around 4,000 ft. weren't there. There weren't any. It's because the duff is too thick and it needs to have a fire come through” (Anderson unpublished field notes 1991). T. Carsoner said: “Everything is overgrown today. Brush, incense cedar seedlings, and pine needles are inundating our mushroom gathering areas. My Aunt Etta said that they used to burn under the ponderosa pines, sugar pines, and black oaks for helli —the pine mushroom” (Anderson unpublished field notes 2010).
Case Study 2: Mixed Evergreen Forests of Northern California
The mixed evergreen forests occur in the outer Coast Ranges and western Klamath-Siskiyou Mountains of northern California, spanning from sea level to over 2100 m elevation. They are composed of Douglas-fir, tanoak, and Pacific madrone (Arbutus menziesii Pursh), with differing proportions of giant chinquapin (Chrysolepis chrysophylla (Hook.) Hjelmq.), sugar pine, ponderosa pine, canyon live oak (Quercus chrysolepis Liebm.), California black oak, big-leaf maple (Acer macrophyllum Pursh), and redwood (Sequoia sempervirens (D. Don) Endl.). American matsutakes and other mushroom species are closely associated with this forest type and were gathered along with an array of many other products. A Karuk woman interviewed in 1981 illustrated this point:
Bear-grass [Xerophyllum tenax (Pursh) Nutt.], hazel [Corylus cornuta Marsh. subsp. californica (A. DC.) E. Murray], chinquapin, and mushrooms are collected. Entire families would go gathering and hunting in the mountains in the fall. They would set up camps and dry part of their meat at the camps. The families would usually gather nuts at this time. [They would g]ather white acorns usually in special family-owned plots (USDA-FS 1981 Interview 299).
Redwoods, sugar pines, ponderosa pines, and California black oaks are well adapted to fire. The pines, oaks, and redwoods have thick insulated bark to protect them from fire damage, and the oaks and redwoods send up new shoots from various portions of the plant following fire injury (Spurr and Barnes 1980). Indigenous burning in the mixed evergreen forests is well-documented in the historical literature (Gifford 1939–1940; Kroeber 1939) and implied through dendrochronological studies that show short-enough fire return intervals to argue two sources of ignition: lightning and Indians (Lorimer et al. 2009; Skinner et al. 2006; Stuart and Stephens 2006; Taylor and Skinner 1998).
Through oral interviews, Native Americans in the Karuk, Yurok, Hupa and other tribes remember multiple reasons for burning in this forest type among which is to increase different kinds of mushrooms that grow on the forest floor and on dead wood of trees killed by fire (Lake 2007). According to a Karuk elder (Karuk Tribe and Cultural Solutions 1999:Appendix 1:30): “Fire was one of the Karuk's main management tools. Fire was used to encourage vegetation growth in plants that were used for food and medicine. Fire was used to create animal habitat. Fire was used for healthier tanoak groves.” L. Glaze remembered her dad telling her that the Karuk burned after the acorns had dropped, “to clear the brush and open things up” (Anderson unpublished field notes 2005). Her grandmother, Catherine Ferris, talked about burning specifically under the tanoaks where the American matsutakes grow in late October or November, and “from everything I've ever heard,” said Glaze, “fire helped the oaks.”
Edible mushrooms gathered by Northwestern tribes that may have benefited from Indian-set fires include American matsutakes, golden chanterelles, corals, black trumpets, and hedgehogs. All of these mushrooms are mycorrhizal with hardwoods and/or conifers (Table 2). Hupa elder Wilfred Colegrove remembered that after the Megram wildfire in 1999 all different types of mushrooms did well “the third and fourth year after the burn” (Lake 2007:433). Burning may have helped certain mushrooms by eliminating insect pests that attack host trees and reducing duff layers, as a Yurok woman relayed to Lake (2007:649):
Oh I think a lot of the underbrush should be taken out everywhere, you know. Those light burns, controlled burns. They don't need a lot of these bugs and beetles they're [e.g., federal agencies] always trying to save. I think a lot of those eat up the trees and there's a lot of bad ones that need to be burned. And take the surface layer off, and let the mushrooms grow and whatever.
Grant Hillman, Karuk, also remembered a much more open forest in an earlier time: “…that was our gathering grounds for the acorns and the mushrooms, and at that time [prior to fire suppression and vegetation densification] you could walk any place in there. And the deer, everything was in there” (Lake 2007:488). When asked if mushrooms liked fire, Hillman replied: “Yeah, you bet they liked it” (Lake 2007:491). Burning also created greater access to mushroom gathering grounds, which today is an issue because the forest is so overgrown. According to Glaze:
Where I go, you know you go to the tanoaks, to get tanoak [American matsutake] mushrooms, I know down below on the ridge you can't get through it now because all the older oaks have fallen over, you know. We used to pick [mushrooms] clear down to the creek and walk the creek clear up, pickin' mushrooms but you can't get through anymore. So if any place needs to be burned, that needs to be burned too (Lake 2007:463).
Charlie Thom, Karuk, agrees that mushrooms do better after a fire, and with fire suppression, he lamented: “Nowadays you can't find the mushrooms” (Lake 2007:631).
According to the scientific literature, fire can be either beneficial or detrimental to populations of fungi, both their above ground fruiting bodies and their below-ground networks of mycorrhizae in different habitats (Duchesne and Weber 1993; Hosford et al. 1997; Molina et al. 2001; Pilz et al. 2004; Southworth and Gibson 2010; Stendell et al. 1999; Trappe, Cromack et al. 2009; Waters et al. 1994). Fire ecologists and mycologists stress that the ecological effects of fire on fungal community dynamics are complex and dependent upon factors such as the season of burn, intensity and resulting severity of a burn, and fire frequency (Molina et al. 2001). Although we have a fairly good idea of why indigenous people in California burned habitats in which valued mushrooms occur, we have not compiled the extensive data here about how they did so. These California Indian fire regime properties include: ignition strategies used, fire intensity, how frequently they burned, the time of year they chose for burning, and how they realized the different cultural goals of burning. We do not know if the habitat for some kinds of mushrooms were burned one way, and the habitat for others burned a different way, depending upon what else Indians were burning for —such as opening habitat, increasing forage for game animals, or stimulating young shrub, forb, or grass growth for basketry. Hundreds of species of mushrooms occur within the two forest types discussed in the case studies, and thus, the useful mushrooms sought by California Indians are a small subset of that diversity. Potential detrimental ecological effects of Indian-set fires are that they probably did not equally benefit all groups of fungi; the fires were harmful to some while benefiting others.
Potential positive ecological effects of Indian-set fires are that they may reduce plants that compete with useful mushrooms (Hebel et al. 2009). The introduction of exotic grasses, for example, may hinder mushroom emergence as Dr. Michael Allen (personal communication 2005) pointed out:
My observation has been that if there is a dense stand of invasive grasses under the oaks, then the mushrooms don't tend to fruit, particularly the mycorrhizal mushrooms. So it makes a lot of sense to do these burnings. The fungi are there in the microscopic threads in the soil and they are associated with the trees, but they won't actually produce a fruiting structure if the grass is dense.
Additionally, explained Allen (personal communication 2005): “Enhancing numbers and size of mushrooms may not only increase mushroom numbers, but heighten genetic diversity in these mushrooms as well.” Beyond benefiting the useful mushroom —a single life-form— at the genetic, organism, and population level, Indian-set fires could also have positive effects at higher levels of biological organization at the plant community and watershed scales. Many of the mushroom species consumed by Indians are also delectable to wildlife as M. Beecher pointed out: “Bears, coyotes, foxes, raccoons —the four-legged animals all like toopO” (Anderson unpublished field notes 2006). N. Turner Behill said: “Cayaakē' grows under the pines. We take the bigger ones. They were dried. It grows like a cauliflower. The deer and bears eat all of these mushrooms” (Anderson unpublished field notes 2006).
Enhanced numbers of sporocarps of certain species resulting from burning might have provided an important source of nutrition by enriching the food web for wildlife such as squirrels, chipmunks, bears, elk, black-tailed and mule deer, and foxes. More open areas provided greater animal access to these mushrooms, and in turn, these animals may play a role in mushroom spore dispersal (Hosford et al. 1997). Furthermore as outlined in the two case studies, there is a significant body of evidence indicating that Indians set fires in the montane mixed conifer forests and mixed evergreen forests for different broader purposes, and achieving some of these other goals could also enhance useful mushroom habitat at the community scale. There are reasons to believe that the regime of Indian burning in these forests contributed to the benefit of certain edible mushrooms through the enhancement of the forest trees.
Many native elders talk today about Indian burning to keep the forests open and the trees healthy and disease-free. In both earlier anthropological accounts and in more recent interviews, native consultants sometimes mention control of disease as one of the many positive effects of burning under trees. After researching the management by fire practices of the Lassik and Pitch Wailaki in the Eel River basin and Yurok in the areas to the north of the North Fork of the Eel, Keter (1985; 1987) concluded that the people in these tribes viewed burning as a way of keeping down diseases of forest vegetation. When Sara Schenck and Edward Gifford (1952) visited the Karuk, Mamie Offield told them that the tanoak trees were “better if they are scorched by fire each year” because the fire, among other things, killed “disease and pests.”
In our interviews with Miwok and Mono elders, they talk about the paradoxical effects of setting fires to prevent catastrophic fires that would kill big trees. “They burned so they would not have big fires,” said Virginia Jeff, Central Sierra Me-Wuk (Anderson unpublished field notes 1989). F. Sherman recalled: “They set fires every year so it didn't harm the trees. That way it would burn the grass. A lot of bushes would burn” (Anderson unpublished field notes 1991). Many of the pines and oaks undoubtedly would not have grown so large had it not been for indigenous burning practices, which kept the brush down and minimized the possibility of catastrophic crown fires (Anderson 2005b).
Western scientists recognize that mycorrhizal fungi are at least partially reliant on the number, growth, and health of their host tree species (Pilz 2011), and that prescribed burning can be an effective tool in opening up the structure of mixed conifer forests at the stand to landscape scale (van Mantgem et al. 2011). We hypothesize that frequent Indian-set surface fires in certain areas, along with lightning ignitions, opened up the structure of the forests and “thinned” the trees, leading to reduced stocking of trees. With reduced drought stress, less competition for water, nutrients or sunlight, and reduced defoliation by insects and pathogens, host trees were healthier and more vigorous. Additionally, we hypothesize that Indian-set fires that led to fewer trees per acre provided suitable environmental conditions for these trees to grow larger and older. These trees were of larger diameter and more widely spaced, and had canopies with greater leaf surface area, leading to enhanced tree photosynthesis. Trees with less plant competition and heightened photosynthesis would bring much more simple sugars and carbon to certain mycorrhizal fungi utilized for human purposes (Egli et al. 2010) than thickets of stressed, spindly firs, pines, or oaks, which are more common now in mixed conifer forests as the result of fire suppression and exclusion (Parsons and DeBenedetti 1979).
Pilz (2011) stated that young forest stands often do not produce large quantities of edible ectomycorrhizal fungi, whereas older trees with sufficient amounts of surplus carbohydrates foster edible species such as chanterelles, American matsutakes, and others. Pilz et al. 2006 (cited in Pilz 2011:146) speculated that “thinning these forests to reduce competition might extend this period of abundant fruiting by prolonging the period of vigorous tree growth among the residual trees.” Greater carbon available to the mycorrhizae, in turn, would lead to a potential extension of hyphae horizontally and vertically in the soil over wider areas beyond the depletion zones created by the tree roots themselves to bring more nutrients back to the trees, positively affecting host tree productivity (Southworth and Gibson 2010). Additionally, frequent surface fires that reduced duff/litter may have resulted in hyphae that were deeper in the humus layers and thus more protected from the penetrating heat of fire down in the soil matrix.
We do not have detailed explanations for exactly how mushrooms and ecosystems were enhanced by Indian-set fires. But if we look to countries in Europe, they have reported the integral role that humans have played in enhancing useful mushroom populations through the ancient techniques of burning and thinning to foster edible and medicinal mushrooms (Arnolds 1991). Additionally, Japanese researchers are improving mushroom populations through modern management that may simulate ancient techniques. Ideal conditions for fostering the Japanese matsutake (Tricholoma matsutake) are an open pine canopy that allows light to penetrate to a sparsely vegetated forest floor and warm, well-drained soils with thin litter and organic layers (Hosford et al. 1997). And Japanese foresters try to simulate these conditions through mild controlled burns to clear understory growth and reduce litter depth, and by thinning trees. These techniques increase Japanese matsutake production and may benefit American matsutake fruiting conditions as well (Hosford et al. 1997:46).
Fungi play an integral role in nutrient cycling and retention, mycorrhizal mutualisms, and are important in terrestrial food chains. Given that fungi are of great ecological significance to our forests —contributing to their health, resiliency, and sustainability— fungi should be considered in the management of our forest resources (Trappe, Molina et al. 2009). Today, our public lands are managed for multiple purposes to meet an array of public values including timber production, recreation, conservation of rare species, and wilderness (Molina et al. 2001). A relatively new value that has emerged is managing for non-timber products including floral greens from herbs, shrubs, and trees, wild fruits, weaving and dyeing materials, specialty wood products, and edible fungi (Davidson-Hunt et al. 2001; Vance and Thomas 1997).
As it is recognized that diverse fungi in wildland ecosystems require different host plant species, disturbance regimes, and environmental conditions, managers and conservationists stress stewarding at the ecosystem scale and put forth the principle of risk-spreading or not managing in the same manner everywhere (Cunningham 2011; Molina et al. 2001). In addition to disturbances created by abiotic factors, which tend to occur randomly across a landscape, there are disturbances attributable to indigenous peoples, which tend to occur non-randomly across the landscape and through time (Anderson and Barbour 2003). Examining tribal harvesting and burning practices that encourage useful mushrooms and other products which have evolved locally and regionally over long periods of time may offer us an important source of knowledge and experience for improving forest ecosystem management (Berkes et al. 2000).
Indigenous mushroom harvesters today still show concern for different fungi's inherent capacity for renewal. The quantity and quality of harvest are adjusted to the biology of the species —both its above-ground aspects (fruiting bodies) and its below-ground aspects (the mycelium). Attention to size and yields of mushrooms gathered and tools that preserve that abundance may well add up to sustained yields. Some of these same harvesting practices are already recommended in modern management contexts (e.g., do not disturb the mycelium, leave small mushrooms to grow larger and old mushrooms to spread their spores), pointing to common ground between traditional and modern management (Lepofsky 2009; Lertzman 2009; Pilz 2011). Burning practices of California Indians likely enhanced or maintained the abundance, density, size, and genetic diversity of different useful mushrooms. Thus, the maintenance of some species of fungi might be served by the continuation of these long-standing practices.
If ecological field experiments that simulate indigenous harvesting and burning demonstrate enhanced mushroom numbers and size, then integrating their management and sustainable harvest as part of multi-use forests would be an appropriate part of conservation and restoration plans (Anderson and Barbour 2003; Molina et al. 2001; Pilz and Molina 1996). Monitoring based upon the principles of adaptive management offers opportunities to evaluate the implications of the tribal management practices (Berkes et al. 2000; Shindler and Cheek 1999; Stankey et al. 2005).
Suggested Avenues of Research
Reintroducing fungi harvesting and management practices that simulate indigenous techniques in our forests needs to be guided by sound science. We propose multi-disciplinary research that combines ecological field experiments, ecological modeling, and indigenous, place-based forms of knowledge in order to simulate indigenous harvesting patterns and land management practices. New research findings could then be used to write management prescriptions for specific areas. These prescriptions would be modified as climate or other variables change. The management techniques are not static but rather are based on adaptive management. Potential research collaborations between scientists and tribal communities include the following topics:
Conduct museum studies that identify edible and medicinal fungi useful to particular indigenous cultures. Mushrooms acquired from California Indian consultants in the early 20th century are housed in various museum collections around the country (Anderson 2005a). With new DNA analysis technology, these could be scientifically identified and would assist tribal cultures in reviving their ethnomycological knowledge. Through our taxonomic identifications of mushrooms currently used by tribes, we hope to assist tribes in the reconstruction of all species used in the past and heighten Western understanding and respect for native knowledge. Scientific identifications of mushroom species can lead to even greater knowledge exchanges as the tribes are given Western scientific articles and reports on the life history, habitat requirements, and interactions of the mushrooms of interest.
Conduct nutritional and medicinal analyses of mushrooms harvested by California Indians that have no current data available. Results may reveal potential treatments for diabetes or other health ailments, or for first-aid/healing applications.
Reconstruct indigenous burning regimes of specific areas of California through interviews, exhaustive literature reviews, and fire behavior modeling as closely as possible, specifying season, frequency, extent, severity, and purpose of Indian burning. Much indigenous mycological knowledge is already lost, as each year there are fewer living elders remembering these traditions.
Measure ecological effects of indigenous gathering and tending practices through non-replicated adaptive management trials and if funding permits, replicated ecological field experiments. Studies could be designed to measure changes in mushroom numbers, mushroom genetic diversity and changes in mycorrhizal populations with simulated Indian gathering and burning regimes. Best management practices for harvest could be developed from field-based manipulative experimentation. Such data could demonstrate the effects of harvesting and burning for specific taxa and associated habitats. Note that it may be problematic to reintroduce low-intensity and localized burning simulating the historical practices of native people, which may produce different ecological effects today due to climate change, the presence of alien plant species, and the need to reduce fuels due to many years of fire suppression and exclusion in different parts of California. All of these factors may likely increase the severity and extent of wildfires, not at all similar to former Indian-set fires (Sugihara and Barbour 2006).
Conduct socio-economic feasibility research of the value of integrated utilization of non-timber forest products, including mushrooms, versus short-term rotation silvicultural timber harvesting (Alexander et al. 2002).
Research and monitor the abundance and productivity of edible mushroom taxa as indicators of climate change and forest health. Sampling fungi seasonally, along an environmental gradient, could provide details of how fungi may link soil productivity to forests within variable climate zones (Buntgen et al. 2011).
Research and monitor how edible fungi and associated ectomycorrhizae are affected by exotic pathogen impacts on host trees and shrubs. For example, in California, Sudden Oak Death (Phytophthora ramorum) affects many tree and shrub host species of culturally significant mushrooms (Ortiz 2008).
In California and elsewhere, restoring species to viable population numbers and preserving or restoring ecosystems on wildlands revolves around the captive breeding and reintroduction of animals; the propagation, cultivation and out-planting of plants; establishing reserves; and restoring functioning habitats (Falk et al. 2006; McNeely et al. 1990; Morrison 2009). But ultimately with these kinds of restoration schemes, humans leave after implementation, as they are perceived as no longer being needed. In addition to these typical restoration schemes, we can re-create specific human-ecosystem associations within designated areas (Anderson 2005b). We propose a new kind of restoration that complements other forms of ecological restoration, called “ethnoecological restoration.” This kind of restoration holds as a premise that parts of the landscapes that we inherited from our forebears still bear the marks of former California Indian stewardship (Anderson and Wohlgemuth 2012). It recognizes that the direct witness and relationship with biological and physical phenomena in nature that Native Americans experienced day after day, year after year, generation after generation is a valid and important way of learning that complements our modern technologies and scientific methods to study and manage the environment.
David Egan, former editor of Ecological Restoration, defines this kind of restoration as “the practice of re-establishing the historic plant and animal communities of a given area or region and renewing the ecosystem and cultural functions necessary to maintain these communities now and into the future” (Anderson 2005b). Restoring the cultural functions would include vegetation management and cultivation practices such as seed-beating, burning, pruning, sowing, tilling, and weeding. In addition to tribal parks and community forests (California Forest Stewardship Program 2011; Trees Foundation 2008), there could be a new land use category on public lands devoted specifically to ethnoecological reserves that encourage sustainable harvesting, adaptive management, research, and restoration of indigenous stewardship practices or the simulation of such interactions with the natural world.
 The map in this article is linguistic, identifying groups of people that spoke the same language or dialect. Today, tribes do not necessarily go by these names. “Sierra Miwok” on the map, for example, are made up of several sociopolitical groups that go by different names today, thus, the variation in spelling: Miwok, Me-Wuk, and Miwuk.
We would like to thank all of the native people who have generously shared their knowledge and practices with us over the years and given their consent to quote them (Anderson and Lake fieldwork). We are grateful to Melba Beecher, LaVerne Glaze, and Phyllis Montgomery for permission to take their photographs and publish them. We appreciate support for our work provided by the University of California Integrated Hardwood Range Management Program, the Yosemite Association, and Yosemite National Park. James Agee, Michael Allen, Max Creasy, Dan Luoma, Dave Perry, David Pilz, Carl Skinner, and Jane Smith reviewed the manuscript and offered valuable editorial improvements. Hope Woodward translated and edited the abstract. Barbara Balen and Candra Neff facilitated interviews with the Central Sierra Me-Wuk. Sherrie Smith-Ferri selected John Hudson field notes with mushroom information from the Grace Hudson Museum Archives for review. Bill Helmer searched the scanned field notes of Frank J. Essene, and Frederick S. Hulse for mushroom information on the Paiute. Thomas Bruns provided a history of mycology at the University of California, Berkeley. Christopher Thayer and Michael Wood visually identified fungus specimens from the Oakland Museum, and Michael Wood assisted with updating the scientific nomenclature. Mike Davis identified mushrooms sent from the field through ocular methods and DNA analysis. Michelle T. Seidl and Isabel Tavares offered possible identifications for some of the mushroom descriptions. Steve Oerding designed the map.