Study area

It was located at the San Jose educational park, which is bordered on the north by the foothills of the natural protected area Huitepec (Instituto de Historia Natural y Ecología^{[IHN], 2004}) and is located at 9 km southwest of the city of San Cristobal de las Casas, Chiapas (Figure 1). Its predominant vegetation is the pine-oak forest and oak-pine, overhanging the following tree species: Pinus ayacahuite, P. strobus, P. teocote, P. montezumae, P. oocarpa, Quercus oleoides, Q. lancifolia and Q. chartacea (^{Álvarez-Espinoza, 2006}). There is no permanent surface water on the site, and it is only temporarily crossed by the runoff of rainwater from the higher surrounding areas (IHN, 2004).

Source: Author’s own elaboration.

Figure 1 Localization of the San José educational park. Panamerican Road Km. 77.7, Tuxtla- San Cristobal s/n, 29200 Zinacantán, Chiapas. 

Sample collection and determination

The sample collection was performed on 12 mycological paths over the five years of the study, in order to explore and determine the macrofungal diversity of the studied area. Sampling was conducted through random walks crossing points throughout the area. This work consisted of listing the species collected in the SJ macromycetes park between the months of May and November, during the years 2009 to 2013. The collected specimens were identified according to their morphological characters with dichotomous keys and herborization. The macroscopic characteristics for determination were color, size, type of hymenium, presence/absence of volva, ring and other ornaments. The microscopic characteristics for determination were spore form and size. Data collection and data field recording were carried out according to ^{Guzmán (1977)} and screened for macromycetes growing on different substrates. Following the determination, the studied specimens were deposited in the Herbarium at the Institute of Natural History of the State of Chiapas. The identification was made using a macro and microscopic analysis based on the concept of morphospecies. In cuts for microscopic analysis of the fruiting body with spores, color changes were observed when adding 5% potassium hidroxide (KOH), methylene blue, and Congo red. Such determination was made using dichotomous keys and consulting specialized literature (^{Díaz-Barriga, 1992}; ^{Gilbertson, 1979}; ^{Gilbertson & Ryvarden, 1986}; ¹⁹⁸⁷; ^{Guzman, 1977}; ¹⁹⁷⁹; ^{Moser, 1978}).

Substrates

Macromycetes on humus (110 species) and on wood (32 species) were the most common. This is probably correlated with the type of vegetation, that is, pine-oak and oak-pine which constantly shed fascicles (pine needles) and broad leaves of Quercus, thereby, creating acid soil and high humidity which, along with the variety of microhabitat, produce the development of fungi on humus (^{Lodge & Cantrell, 1995}). This is consistent with those reported by ^{Guzmán-Dávalos & Guzmán (1979)}, who claim there are more lignicolous fungi in the tropics than in coniferous forests due to weather factors that promote the formation of humus.

Saprobes and ectomycorrhizal species

In addition, the results indicate that the group of saprobe fungi were the most common (68 species, 46.25%), followed by the ectomycorrhizal species (59 species, 40.13%). This is probably due to the fact that mycorrhizae develop in greater proportion in coniferous forests, compared to forests or rainforests, probably because weather conditions are generally not the most adequate; therefore, trees need to partner with other living organisms and other agents in order to properly absorb nutrients (^{Guzmán-Dávalos & Guzmán, 1979}). Based on the results obtained, the families Amanitaceae (16 species, 10.88%), Tricholomataceae (15 species, 10.20%), and Boletaceae (12 species, 8.16%) were the most abundant within the group of mycorrhizae, which play a role in developing ecological forest populations and ecological succession, as well as in the promotion and alteration of the functions of niches (Kadowaki et al., 2018). According to the findings by ^{Garza, García & Castillo (1985)}, the genus Amanita is closely linked to productivity and the maintenance of a healthy forest. Some ectomycorrhizae, like Amanita and Russula, can use vegetable cellulose and polymers for degradation by joining broadleaf trees such as oaks, hence the importance of the study area where some species of Quercus sp. are dominant (^{Deacon, 1993}).

The most common genera of ectomycorrhizal fungi observed were Amanita, Boletus, Cantharellus, Clavariadelphus, Clitocybe, Gyromytra, Helvella, Inocybe, Laccaria, Lactarius, Ramaria, Russula, Scleroderma and Suillus; therefore, it can be concluded that these taxonomic groups are abundant in Quercus forests (^{López-Eustaquio, Portugal, Bautista & Venegas, 2010}; ^{Pérez-Silva, Esqueda, Herrera & Coronado, 2006}). ^{Guzmán-Dávalos & Guzmán (1979)} and ^{Landeros, Castillo, Guzmán & Cifuentes (2006)} also found abundant ectomicorrizogen species in these type of forests.

Edible fungi

A total of 43 (31.29%) edible species were found: Agaricus silvaticus, Aleuria aurantia, Amanita vaginata, Amanita caesarea, Amanita fulva, Amanita rubescens, Amanita vittadini, Armillariella mellea, Auricularia auricula, Boletellus betula, Cantharellus cibarius, Cantharellus tubaeformis, Clavariadelphus pistillaris, Clitocybe clavipes, Clitocybe gibba, Collybia dryophilus, Coltricia perennis, Coprinus atramentarius, Cortinarius violaceus, Craterellus cornucopioides, Craterellus lutescens, Gyromitra infula, Helvella crispa, Helvella lacunose, Hydnum repandum, Hygrophoropsis aurantiaca, Laccaria amethystina, Laccaria laccata, Lactarius deliciosus, Leotia lubrica, Lyophyllum decastes, Macrolepiota procera, Macropodia macropus, Oudemansiella canarii, Paxina acetabulum, Phallus impudicus, Pleurotus djamor, Ramaria stricta, Rozites caperatus, Russula brevipes, Russula cyanoxantha, Schizophyllum commune and Sparassis crispa. These species might be a sustainable food alternative for residents near the SJ park, as they could be used sustainably with biotechnological processes through cultivation; therefore, they can be considered as non-timber forest resources to contribute to the forest conservation and form a fundamental part of the structure and operation thereof, aiding in the capture of water, the conservation of diversity and as a source of income through alternative tourism or ecotourism (^{Pilz, Norvell, Danell & Molina, 2003}).

Toxic fungi

Twenty-two (14.96%) taxa of toxic and hallucinogen fungi were found: Amanita citrina, A. codinae, A. flavoconia, A. gemmata, A. hemibapha, A. muscaria, A. pantherina, A. virosa, Chlorophyllum molybdites, Hypholoma fasciculare, Inocybe sp. 1, Inocybe sp. 2, Omphalotus olearius, Panaeolus semiovatus, Phellodon niger, Pholiota squarrosa, Psilocybe sp., Russula mexicana, Russula subfoetens, Sarcosphaera eximia, Scleroderma areolatum and Tricholoma equestre. The most abundant genera were Amanita; some of them may cause mycetism due to their toxicity (^{Díaz-Barriga, Guevara, Ferer & Valenzuela, 1988}; ^{Garza et al., 1985}). Chlorophyllum molybdites and Scleroderma areolatum produce gastrointestinal mycetism, characterized by headache, fatigue, nausea, vomiting and diarrhea (^{Ott, Guzmán, Romano & Díaz, 1975}). Gyromitra esculenta, although it is considered edible in some regions of Mexico, can have a neurotoxic effect (^{Carod-Artal, 2005}). Coprinus atramentarius causes Coprinic syndrome, or disulfiram reaction (^{Pérez-Silva et al., 2006}), while some species of Amanita, Clitocybe y Omphalotus contain muscarin and, therefore, may cause muscarinic syndrome. Amanita muscaria is one of the most toxic species known in Mexico, and it is considered toxic, hallucinogenic, medicinal and is even used as an insecticide. Some species of Helvella and Gyromitra can be eaten boiled, and the boiling water should be discarded, because they are toxic when consumed raw. According to ^{Madrid (2005)}, Schizophyllum commune causes sinusitis, bronchopulmonary fungal infections, meningitis and lesions of the palate, although in Chiapas it is considered an edible mushroom. Only two fungi species (hallucinogens) growing on dung were found (1.36%), indicating that despite the fact of the area having moderate or latent disturbances, the incidence of free wild animals and/or livestock within the park is low. The zoo cages were not sampled due to security reasons. These results agree with ^{Heredia (1989)} at the Reserva El Cielo; both are protected areas. The ratio toxic: edible fungi was 1:2.3, which means that edible mushrooms are more abundant than toxic fungi.

Fungi with biotechnological and medical applications

Inside the SJ park, some fungi were found to have biotechnological and medical applications. Cortinarius violaceus, according to local knowledge, is a fungus used for the extraction of dyes which produce a stained purple-violet color. The dye can be extracted with a 70% ethanol solution. In Mexico, and specifically in Chiapas, some species are considered to have medicinal properties, such as: Amanita muscaria, Clitocybe gibba, Coprinus atramentarius, Ganoderma lucidum, Geastrum triplex, Hydnum repandum, Lactarius deliciosus, Leotia lubrica, Schizophyllum commune, Scleroderma areolatum, Sparassis crispa and Trametes versicolor. According to ^{Ceballos et al. (2009)}, in México, Amanita muscaria and Lactarius indigo are used as purgatives; Amanita caesarea is used as an anti-inflammatory, and Lactarius deliciosus is used for asthma and intestinal pains. According to the results of this study, the mycological value of SJ park is higher than that of the Parque Educativo Laguna Bélgica, another park in Chiapas (^{Chanona-Gómez et al., 2007}).