Plot-based observations of macrofungi in major ecosystem types of taiga zone, Western Siberia

Nina Filippova, Elena Lapshina

The area of study is located in the middle taiga zone of Western Siberia. For the purpose of permanent monitoring of fungal communities of local ecosystems, two sites were chosen at about 20 km SW and E from the Khanty-Mansiysk town nearby two field stations of Yugra State University.

The recommended protocols for sampling macrofungi were followed during the project (O'Dell et al. 2004, Mueller et al. 2019). A series of subplots was established in a raised bog (totally 263) (corresponding to two "virtual plots" with two different vegetation types). Another ten plots were established in different forest types following after-logging and paludification successions (in total, 300 subplots). These plot-based observations were also supplemented by opportunistic routs to record rare species and habitats. Due to variations in fruiting in relation to weather conditions and internal fruiting dynamics, the plot-based monitoring should be continued for at least 10 years and this project will try to follow these goals; the datasets will be updated after new data have been collected.

The project is partially funded by the Yugra State University grant #13-01-20/39. Permanent monitoring at the Mukhrino Field Station is also supported by INTERACT – International Network for Terrestrial Research and Monitoring in the Arctic (https://eu-interact.org).

The long-term monitoring plots were located along a walking board of the research polygon of Mukhrino Field Station (Fig. 1), thereby eliminating any future impacts to the bog as a result of ongoing research programmes. A total of 263 circular x 5 m² (for a total area of 1,315 m²) long-term monitoring subplots were established in May 2014. This total area is nearly evenly divided between the two major plant communities (two "virtual plots"): Pine-dwarfshrubs-Sphagnum dominated bogs (dominated by Pinus sylvestris, Chamaedaphne calyculata, Ledum palustre, Rubus chamaemorus, Sphagnum fuscum) and Graminoid-Sphagnum lawns (dominated by Scheuchzeria palustris, Carex limosa, Eriophorum russeolum, Oxycoccus palustris, Sphagnum balticum) and incorporates plant community variation. An area of about 700 m² is sufficiently large to reveal the fungal community diversity in raised bogs, based on species accumulation curves constructed from these data.

Figure 1.  

General view of the Mukhrino Fields Station infrastructure and position of subplots for observation of macromycetes located along the walking board (in the insert).

The recommended protocols for sampling macrofungi were followed in general terms (O'Dell et al. 2004). Four steps of the protocol: selection of observation site, transects and subplots installation, carpophore counting and collecting specimens are described in detail in a published protocol by Mueller et al. (2019).

About 1,000 dry specimens were collected in line with the project. The collection database is available at: (https://fungariumysu.org/fungarium-ysu-database; https://www.gbif.org/dataset/d922b606-6c94-4d51-9277-36c9b03872a7). All identifications were made by the first author and some collections were sent to experts in a particular taxonomic group for proper naming. Future thorough taxonomic work is also necessary for some taxonomically difficult genera like Cortinarius, Russula and Galerina.

In order to preserve the peatland surface, the long-term monitoring subplots were located 5 m apart in a straight line along the walking boards throughout their length. The plots were chosen by ensuring that they fell only into a single plant community. Centres of each subplot were marked with a metal label on the walking board side and a bent bow was used to draw the outlines of a subplot during its examination (Fig. 2).

Figure 2.  

The example of examination of a subplot located in Graminoid-Sphagnum lawn community using a bent bow to draw the outlines (total area of a circular subplot = 5 m²)

A total of 263 circular 5 m² (for a total area of 1,315 m²) long-term monitoring subplots were established in May 2014. The subplots were inspected weekly from May to September in 2014-2018 (except for August 2017 when observations were interrupted and some occasional gaps in observations which were interpolated during the following quantitative analyses). All carpophores of each species were counted and collected for subsequent examination. Enumerated carpophores were carefully removed from the subplots, with the exception of Red Listed taxa (Ascocoryne turficola, Entoloma fuscomarginatum, Geoglossum sphagnophilum, Hygrocybe cinerella, Mycena concolor, Omphaliaster borealis, Psilocybe turficola), whose carpophores remained untouched.

Climatic data (precipitation, air temperature, soil profile temperature) were collected from a micro-climate monitoring station established nearby the plots (https://mukhrinostation.com/research/weather-station/). The description of vegetation was made in each subplot using the general relevé approach.

The common and easily recognisable species were identified in the field. The detailed identification of doubtful species was done in the laboratory. Most of the specimens were identified using Funga Nordica keys (Knudsen and Vesterholt 2008) and some additional monographs on particular taxa were used when necessary. The old fruiting bodies which were difficult to assign to a particular species were left with the genus level identification (about 100 of this kind of records in the database).

The collections were processed as described in Lodge et al. (2004). Fresh fruiting bodies were wrapped in aluminium foil and carried to the laboratory to be processed on the day of collection. The processing of specimens included:

1. photographing on a photo-studio table;
2. description of vital characters;
3. preliminary microscopy and identification;
4. filling the data in the database;
5. labelling;
6. drying at 50°C to store in the Fungarium of Yugra State University;

The detailed identification was done during the winter following the collection season. Dry specimens were rehydrated in tap water or KOH (10%); dyes and other chemicals (Congo Red, Melzer's reagent, ammonia) were applied when necessary. A Zeiss Axiostar microscope with Achromat 5/0.12, 10/0.25, 40/0.65 (dry) and 100/1.25 (oil immersion) objectives was used for microscopical examination.

The studied area is located in the middle taiga zone of Western Siberia. Mukhrino Field Station of Yugra State University was established 30 km SW from Khanty-Mansiysk, nearby the Mukhrina River (left inflow of the Irtysh River). The research polygon of the station, located in a bog, has the infrastructure of walking boards along which the monitoring programme was established. The subplots for long-term monitoring of macrofungi were located along the boardwalk line within the radius of about 500 m from the central coordinate of the infrastructure (60.89188N, 68.68233E).

60.889 and 60.896 Latitude; 68.670 and 68.692 Longitude.

Terrestrial macrofungi (larger fungi) were studied during the survey. The group was defined as the macrofungi which are confined to terrestrial habitat as opposed to wood-inhabiting species representing another prominent community in boreal forests. However, these groups partially overlap and we recorded species growing on mossy old trunks or buried wood within the plots. Our study included the following groups in the analysis: Discomycetes, Agaricoid, Boletoid, Aphyllophoroid fungi (we omitted brackets, crusts and jellies but included clubs and coral fungi) and some other groups in minority. The taxonomic coverage includes representatives of two divisions (Ascomycota - 4 species, Basidiomycota - 65), three classes (Agaricomycetes - 65, Leotiomycetes - 2, Pezizomycetes - 2) and 22 families (Amanitaceae - 1, Auriscalpiaceae - 1, Boletaceae - 1, Clavariaceae - 1, Cortinariaceae - 16, Entolomataceae - 2, Helotiaceae - 1, Hydnangiaceae - 1, Hygrophoraceae - 4, Hymenogastraceae - 12, Inc. sed. - 1, Inocybaceae - 1, lyophyllaceae - 1, Mycenaceae - 5, Omphalotaceae - 3, Physalacriaceae - 1, Russulaceae - 5, Sarcosomataceae - 2, Sclerotiniaceae - 1, Strophariaceae - 3, Suillaceae - 2, Tricholomataceae - 4 species).