Variation in traditional knowledge of culturally important macromycete species among three indigenous communities of Oaxaca, Mexico.

BACKGROUND: For centuries, wild mushrooms have been a forest resource of significant cultural value in several ethnic groups worldwide. In Mexico, extensive traditional knowledge on the use of fungal resources has been developed and deeply rooted. Mexico is the second country in the world in which the most species of wild mushroom are consumed, and it is considered a pioneer in ethnomycology. Nonetheless, there are still many indigenous groups in this country that have not been studied from an ethnomycological approach. The present study aimed to record the traditional knowledge on wild mushrooms in three indigenous groups of the state of Oaxaca, Mexico, and assess the variation in this knowledge within and across the studied groups. METHODS: The data were recorded from April to October 2022 within three communities belonging to the indigenous groups Chatino, Chontal, and Chinanteco. Through 84 interviews, information related to their knowledge of wild mushrooms was obtained. The cultural significance index of wild edible mushrooms was calculated for each community. Regression analyses, analysis of variance and covariance, t test, and non-metric multidimensional scaling analysis were performed to assess the distribution of traditional knowledge in the communities. RESULTS: A total of 32 culturally important mushroom species were recorded for the three indigenous groups (30 edible, 2 medicinal); 23 used by Chatinos, 16 by Chontales, and 6 by Chinantecos. Only Chatinos and Chinantecos use wild mushrooms in medicine. The cultural significance of wild edible mushrooms differed among groups. Traditional knowledge about wild mushrooms declines when the level of schooling increases and age decreases, especially in the Chatino group. This knowledge distributes more homogeneously in the Chontal and Chinanteco groups. Their age determines the difference in knowledge between men and women. CONCLUSION: Documenting how traditional knowledge differs among ethnic groups is relevant for preserving cultural and biological diversity. Factors such as level of schooling and age can affect traditional knowledge of wild mushrooms, but the effects of these factors vary within and across communities. Conducting studies encompassing a broader range of variables is of interest for a better understanding of the human-mushroom relationship.

No evidence of attentional prioritization for threatening targets in visual search.

Throughout human evolutionary history, snakes have been associated with danger and threat. Research has shown that snakes are prioritized by our attentional system, despite many of us rarely encountering them in our daily lives. We conducted two high-powered, pre-registered experiments (total N = 224) manipulating target prevalence to understand this heightened prioritization of threatening targets. Target prevalence refers to the proportion of trials wherein a target is presented; reductions in prevalence consistently reduce the likelihood that targets will be found. We reasoned that snake targets in visual search should experience weaker effects of low target prevalence compared to non-threatening targets (rabbits) because they should be prioritized by searchers despite appearing rarely. In both experiments, we found evidence of classic prevalence effects but (contrasting prior work) we also found that search for threatening targets was slower and less accurate than for nonthreatening targets. This surprising result is possibly due to methodological issues common in prior studies, including comparatively smaller sample sizes, fewer trials, and a tendency to exclusively examine conditions of relatively high prevalence. Our findings call into question accounts of threat prioritization and suggest that prior attention findings may be constrained to a narrow range of circumstances.

Impact of urbanization on functional diversity in macromycete communities along an urban ecosystem in Southwest Mexico.

Macromycetes are a group of fungi characterized by the production of fruit bodies and are highly relevant in most terrestrial ecosystems as pathogens, mutualists, and organic matter decomposers. Habitat transformation can drastically alter macromycete communities and diminish the contribution of these organisms to ecosystem functioning; however, knowledge on the effect of urbanization on macrofungal communities is scarce. Diversity metrics based on functional traits of macromycete species have shown to be valuable tools to predict how species contribute to ecosystem functionality since traits determine the performance of species in ecosystems. The aim of this study was to assess patterns of species richness, functional diversity, and composition of macrofungi in an urban ecosystem in Southwest Mexico, and to identify microclimatic, environmental, and urban factors related to these patterns in order to infer the effect of urbanization on macromycete communities. We selected four oak forests along an urbanization gradient and established a permanent sampling area of 0.1 ha at each site. Macromycete sampling was carried out every week from June to October 2017. The indices used to measure functional diversity were functional richness (FRic), functional divergence (FDig), and functional evenness (FEve). The metric used to assess variation of macrofungal ecological function along the study area was the functional value. We recorded a total of 134 macromycete species and 223 individuals. Our results indicated a decline of species richness with increased urbanization level related mainly to microclimatic variables, and a high turnover of species composition among study sites, which appears to be related to microclimatic and urbanization variables. FRic decreased with urbanization level, indicating that some of the available resources in the niche space within the most urbanized sites are not being utilized. FDig increased with urbanization, which suggests a high degree of niche differentiation among macromycete species within communities in urbanized areas. FEve did not show notable differences along the urbanization gradient, indicating few variations in the distribution of abundances within the occupied sections of the niche space. Similarly, the functional value was markedly higher in the less urbanized site, suggesting greater performance of functional guilds in that area. Our findings suggest that urbanization has led to a loss of macromycete species and a decrease in functional diversity, causing some sections of the niche space to be hardly occupied and available resources to be under-utilized, which could, to a certain extent, affect ecosystem functioning and stability.

Comparison of diversity and composition of macrofungal species between intensive mushroom harvesting and non-harvesting areas in Oaxaca, Mexico.

Wild edible mushrooms have been collected and consumed by human groups for centuries, and today they represent a relevant source of food and income for many rural families worldwide. Preserving these non-timber forest products is of great interest, and there is concern about the damage caused by intensive mushroom harvesting on macromycete communities. The aim of this study was to evaluate variation in diversity and composition of macromycete species between areas regularly used for mushroom harvesting and non-harvested areas in the Mixteca region of Oaxaca, Mexico, as well as to assess the influence of microclimatic and environmental factors on this variation. We selected two harvested and two non-harvested sites within the study area. In each one, we established 10 permanent plots of 10 m × 10 m where we sampled all the observed fruit bodies weekly from June to October 2017. We recorded a total of 856 individuals corresponding to 138 species, and 23 of these were identified as edible. Overall macromycete diversity, edible species diversity and composition were similar in Sites 1 (non-harvested) and 3 (harvested), and in Sites 2 (non-harvested) and 4 (harvested). Variation of diversity and species composition along the studied area was mainly related to microclimatic variables, while most environmental variables and variables related to vegetation structure similarly affected macromycete species in the four sites. Our results indicate that intensive harvesting of wild edible mushrooms is not affecting the diversity and distribution of macromycete species in our study area. Knowledge on the sustainability of mushroom harvesting practices can help improve current regulations regarding the management of these valuable non-timber forest products.