Mercury in traditionally foraged species of fungi (macromycetes) from the karst area across Yunnan province in China

The objective of this study is to better quantify the occurrence, intake, and potential risk from Hg in fungi traditionally foraged in SW China. The concentrations and intakes of Hg were measured from 42 species including a “hard” flesh type polypore fungi and a” soft” flesh type edible species that are used in traditional herbal medicine, collected during the period 2011–2017. Three profiles of forest topsoil from the Zhenyuan site in 2015 and Changning and Dulong sites in 2016 were also investigated. The concentrations of Hg in composite samples of polypore fungi were usually below 0.1 mg kg−1 dry weight (dw) but higher levels, 0.11 ± 0.01 and 0.24 ± 0.00 mg kg−1 dw, were noted in Ganoderma applanatum and Amauroderma niger respectively, both from the Nujiang site near the town of Lanping in NW Yunnan. Hg concentrations in Boletaceae species were usually well above 1.0 mg kg−1 dw and as high as 10 mg kg−1 dw. The quality of the mushrooms in this study in view of contamination with Hg showed a complex picture. The “worst case” estimations showed probable intake of Hg from 0.006 μg kg−1 body mass (bm) (“hard” type flesh) to 0.25 μg kg−1 bm (“soft” flesh) on a daily basis for capsulated products, from 17 to 83 μg kg−1 bm (“soft” flesh) in a meal (“hard” type flesh mushrooms are not cooked while used in traditional herbal medicine after processing), and from 0.042 to 1.7 and 120 to 580 μg kg−1 bm on a weekly basis, respectively. Graphical abstract Key points • Polypore species were slightly contaminated with Hg. • Hg maximal content in the polypore was < 0.25 mg kg−1dry weight. • Many species from Boletaceae family in Yunnan showed elevated Hg. • Locals who often eat Boletus may take Hg at a dose above the daily reference dose.

Using Red List species in designating protection status to forest areas: a case study on the problem of spatio-temporal dynamics

Red-listed species are often used as target species in selection of sites for conservation. However, limitations to their use have been pointed out, and here we address the problem of expected high spatio-temporal dynamics of red-listed species. We used species data (vascular plants, bryophytes, macrolichens and polypore fungi) from two inventories 17 years apart to estimate temporal turnover of red-listed and non-red-listed species in two forest areas (147 and 195 ha) and of plots (0.25 ha) within each area. Furthermore, we investigated how turnover of species affected the rank order of plots regarding richness of red-listed species, using two different national Red List issues (1998 and 2015). In both study areas, temporal turnover was substantial, despite minor changes in the overall number of species. At plot level, temporal turnover in red-listed species was higher than in non-red-listed species, but similar to non-red-listed species of the same frequency of occurrence. Adding the effect of changing identities of species red-listed according to the two Red List issues, further increased the estimated spatio-temporal dynamics. Recorded spatio-temporal turnover also resulted in substantial changes in the rank order of plots regarding richness of red-listed species. Using rare red-listed species for site selection may therefore be accompanied by a higher loss of conservation effectiveness over time than for more common species, and particularly at finer scales.

Characteristics of boreal and hemiboreal herb-rich forests as habitats for polypore fungi

Herb-rich forests are often considered biodiversity hotspots in the boreal zone but their fungal assemblages, particularly those of wood-decaying fungi, remain poorly known. We studied herb-rich forests as habitats for polypores, a distinct group of wood-decaying fungi, and assessed the importance of tree- and stand-scale variables for polypore species richness, abundance, and diversity, including red-listed species. The data include 71 herb-rich forest stands in Finland and 4797 dead wood items, on which we made 2832 observations of 101 polypore species. Dead-wood diversity was the most important variable explaining polypore species richness and diversity, whereas increasing latitude had a negative effect. Red-listed species showed a positive response to the abundance of large-diameter dead wood, which, especially birch, supported also high general abundance of polypores. The composition of polypore assemblages reflected their host-tree species. The red-listed species did not show explicit patterns in the ordination space. Compared to old-growth spruce forests, herb-rich forests seem to host lower polypore species richness and less red-listed species. However, because of high proportion of deciduous trees in the dead wood profile, herb-rich forests have a clear complementary effect on polypore assemblages in boreal forest landscapes.

Bactericidal activites of selected macrofungi extracts against Staphylococcus aureus

The increasing of the antibiotic resistance exhibited by pathogenic microorganisms has resulted in research directed toward evaluation of novel sources of antimicrobial compounds. Previous studies have indicated that macrofungi, as a specific response to the natural hostile environment, produce secondary metabolites with antimicrobial properties. In this study, antimicrobial activities of the extracts from six wild mushrooms: Amanita echinocephala, Russula medulata, Cerena unicolor, Hericium erinaceus, Ishnoderma benzoinum and Laetiporus sulphureus were evaluated against Grampositive bacterium Staphylococcus aureus. The antimicrobial potential of the methanolic mushroom extracts was investigated by the microdilution method. Antimicrobial activity was observed in all species included in the study. All the extracts that demonstrated inhibitory activities were further tested for bactericidal activity and minimum bactericidal concentration (MBC) values were determined. The tested microorganism was most sensitive to the examined extracts from the polypore fungi C. unicolor and H. erinaceus. The highest bactericidal activity was obtained in the extracts from the species C. unicolor (MBC=1.563 mg/mL). The experimental results revealed that the methanolic extract of C. unicolor possessed significant bactericidal activity. The findings suggest the potential use of this wild mushroom as antimicrobial agent.

Diversity and seasonality of polypore fungi in the moist deciduous forests of Peechi-Vazhani Wildlife Sanctuary, Kerala, India

The objective of present study was to understand the diversity, distribution and seasonality of polypore fungi in the moist deciduous forests of Peechi-Vazhani Wildlife Sanctuary in three different seasons. Results obtained showed that density and frequency of occurrence have been varied significantly during different seasons and the community structure and species composition during monsoon and post monsoon seasons were distinct from pre-monsoon season. Fomitopsis feei with higher abundance values dominated the moist deciduous forests during monsoon season (17.72) and post-monsoon season (13.79). During pre-monsoon season, Daedalea flavida was the dominant species with abundance value of 10.93. The above fungi were predominant during all the seasons due to their high ecological amplitude. Fungal diversity analysis showed that species richness was higher during monsoon season and revealed the influence of seasonal variation on fungal diversity. The high species similarity was observed between monsoon and post monsoon season compared to pre-monsoon and monsoon.