DOI: 10.15468/yfemwn
title: Saproxylic fungi of fine woody debris studied by metabarcoding-based MycoPins method in Oulanka, Finland, 2022-2023

description: This work elucidates succession patterns of saproxylic fungi in undisturbed boreal forests, exploring how environment and forest management practices influence fungal diversity in decaying wood. Leveraging the MycoPins method (Shumskaya, 2023), sterilized wooden pins were placed in the topsoil layer and allowed to decay with subsequent periodic extraction; fungal colonization was monitored across four different forest ecosystems in Finland during 2022-2023. MycoPins were placed in twenty groups of six (sextets: two pins made of pine, two of birch, and two of spruce) along four independent transects: conifer forest with access of reindeer (transect A), conifer forest without access of reindeer (transect B), a broadleaf forest and accessed to tourists (transect C).Reindeer is a keystone species in boreal forests which defines biodiversity of major ecosystems. Cladonia sp. is a lichen that is heavily consumed by reindeer and is in abundance in a protected forest, while almost absent in unprotected forests. Hence, reindeer grazing might have a significant impact on forest microbiome. The research is designed to test several hypotheses: 1). Succession of species is present in fungal communities in deadwood as communities change with progression of decay. 2). Biodiversity of saproxylic fungal guilds is different across different biotopes. 3). Fungal communities differ in hardwood (Angiosperms, broadleaf) vs softwood (Gymnosperms, conifers).

One sextet was collected from each transect biweekly, with breaks if the transect was not accessible due to weather or other circumstances. The fungal communities in each pin were analyzed using DNA metabarcoding, fungal species were identified in each pin and the data uploaded to GBIF.org.The occurrence dataset is represented by events and occurrences, with DNA-derived data provided for each occurrence. Events contain information about different substrates observed in a particular environment (transect) over a period of time. Occurrences are associated with an event and refer to the presence or absence of fungal species on a specific substrate along a transect observed over a given period. The set of fungal species in these occurrences represents those observed throughout the entire observation period. The DNA-derived data of events provide additional details on the identification of fungal species on the substrate samples.Events are identified by an event ID which is composed of the transect identifier (either A, B, or C) and a sample number (six numbers and a letter). Each event ID is associated with a parent event ID which is composed of a transect identifier (either A, B, or C) and the date when the event occurred (collection date in a format YYYY_Month_DD). Occurrences, associated with an event, are identified by an occurrence ID which is composed of an event ID and a GBIF taxon key of a fungal species.

For example, the event &lt;code&gt;A_018561C&lt;/code&gt; pertains to a MycoPin identified by &lt;code&gt;018561C&lt;/code&gt; in transect &lt;code&gt;A&lt;/code&gt;. The parent event id &lt;code&gt;A_2022_Jul_01&lt;/code&gt; refers to collection of all six pins from transect &lt;code&gt;A&lt;/code&gt; that occurred on &lt;code&gt;July 1, 2022&lt;/code&gt;. The occurrence id &lt;code&gt;A_018561C:2613081&lt;/code&gt; represents the &lt;i&gt;Hormonema macrosporum Voronin&lt;/i&gt; (GBIF taxon key: &lt;code&gt;2613081&lt;/code&gt;) in relation to the event &lt;code&gt;A_018561C&lt;/code&gt;.Sampling scheme for each transect are as illustrated as follows:transect Atransect Btransect C