{'fraction_non_alphanumeric': 0.034346103038309116, 'fraction_numerical': 0.024108322324966975, 'mean_word_length': 5.336820083682008, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Seasonality and abundance of truffles from oak woodlands to red fir forests

are an important food source for many small mammals in forest ecosystems; however, we know little about the seasonality, abundance, or diversity of the truffle community in the Sierra Nevada. This study examined how truffle abundance and diversity varied between oak woodland, ponderosa pine (Pinus ponderosa), mixed-conifer, and red fir (Abies magnifica) forests. Species richness (number of species) and abundance of truffles were highest in ponderosa pine stands, but species evenness was greatest in mixed-conifer stands. Truffle biomass peaked in late spring and fall, tracking precipitation patterns with a 1-2 month lag. At least 65 species of truffles were identified in a 1-ha sample of the forest. This number is still only a fraction of the fungal species present, as many mycorrhizae rarely produce fruiting bodies. Truffle production depends on the condition of the truffle's mycorrhizal host trees. Natural or human disturbances, which affect the age and composition of the forest, will affect truffle abundance and the animals that depend on them for a substantial portion of their diet. Scientists and managers are becoming increasingly aware of the importance of the fungal community in forest ecosystems. Mycorrhizal fungi are essential for plant growth and survival; they provide food for many soil biota (Warnock and others 1982); they reduce soil pathogens and bacteria (Marx 1972); and they improve soil structure (Tisdall and Oades 1979). Fungi also produce fleshy fruiting bodies that are an important part of a forest's food chain. Mycorrhizal fungi form above- and below-ground fruiting bodies known, respectively, as epigeous and hypogeous sporocarps, commonly called "mushrooms" and "truffles." Although many forest animals are opportunistic consumers of sporocarps (mycophagy) (Fogel and Trappe 1978), several species of small mammals rely on truffles for a substantial portion of their diet (Maser and others 1978). Animal mycophagists include many species of Geomyidae (pocket gophers), most Microtidae (voles), and almost all Sciuridae (squirrels and chipmunks) in North America (Fogel and Trappe 1978, Maser and others 1978), as well as many forest-dwelling marsupials in Australia (Johnson 1994, Seebeck and others 1989). Many truffle consumers comprise the base of the forest food chain for higher predators (Grenfell and Fasenfest 1979). A well-know example is the connection between truffles, the dominant food source of the northern flying squirrel (Glaucomys sabrinus) (Hall 1991; Maser and others 1985, 1986; McKeever 1960), and the squirrel's importance as the principal prey of the spotted owl (Strix occidentalis) in mesic forests (Forsman and others 1984, 1991; Verner and others 1992). It is essential that we understand how truffle abundance changes with forest conditions because of their substantial influence on small mammal populations and, consequently, the higher predators in the forest's food web.