We investigated the differences of element profiles of particular edible mushrooom species mushrooms between plots. Mushrooms were collected in 1 and 3 tree species plots in FORBIO-Zedelgem and BIOTREE-Kaltenborn and in 1,2,3,4- tree species mixtures in Bialowieza. Elements profile is part of the information about nutritional values of mushrooms (heavy metals content, microelements). We compared them to investigate the impact of tree species richness and other environmental factors on mushroom nutritional values.

Sampling took place in every 1- or 3-species plot (VIP plots) - in Bialowieza also in 2 and 4 species mixtures. Mushrooms were collected at the entire plots (30x30m), extended with a 2,5m-wide stripe of land around (35mx35m). Mushrooms from each plot were collected to separate baskets. Then, we: 1) determined mushrooms species to the lowest possible level 2) weighed fresh mass of each species from every plot separately with 0,1 g accuracy 3) dried the samples in 50℃ for 18h (longer if needed) 4) weighed samples with 0.1 g accuracy 5) took samples of edible mushrooms present in more than 7 plots to a laboratory.

Mushrooms were collected in 1 and 3 tree species plots in FORBIO-Zedelgem and BIOTREE-Kaltenborn and in 1,2,3,4- tree species mixtures in Bialowieza. In Bialowieza we conducted two season long monitoring (June-half of November 2020-2021), collecting mushrooms every ten days (all sporocarps of particular edible species from one plot were pulled together). In Zedelgem and Kaltenborn monitoring was organised twice in 2021 thanks to local support.

sporocarps of all soil-dwelling and epixylic macrofungi (excluding bracket fungi and those with size of the sporocarp <0.5 cm)

sunny or cloudy, around 5-15℃

All mushrooms were identified, categorised into edible and non-edible species and dried in food dehydrator at 50°C for about 24 hours. Mushrooms from particular species, collected in more than 7 plots (in case of Kaltenborn in 5 plots) were taken to the Laboratory of Department of Bromatology of the Jagiellonian University in Cracow for estimation of the concentration of trace elements. Powdered dried mushrooms (300 mg of each sample) were accurately weighed and placed into a Teflon bomb. Subsequently, 5 ml of 65% nitric acid (Merk SupraPure, catalog number 1.00441.1000) were added. After a one-hour period, the probes were hermetically sealed and subjected to digestion in a microwave oven (CEM 2000). The digested solution was then allowed to cool and was further diluted with ultrapure water (Millipore) for total volume 25 ml. The quantification of zinc (Zn), copper (Cu), magnesium (Mg), and manganese (Mn) was conducted via F-AAS using a Perkin-Elmer 5100 ZL instrument, operating with an air-acetylene flame at flow rates ranging from 1.8 to 9.6 liters per minute. For the determination of 17 elements (Ag, As, Ba, Cd, Co, Cr, Ga, Li, Mo, Ni, Pb, Rb, Sb, Se, Sr, Ti, Tl), the ICP-MS technique was employed, utilizing an Elan DRC-e spectrometer (PerkinElmer, Waltham, MA, USA). Two multi-element stock solutions, namely 1.10580.0100 (Merck) and CHECL 01.13632.0100, were employed as internal standards. To ensure accuracy and precision, a certified reference material, BCR-482 (lichens), was utilized. This file contain the results of these analyses - the concentrations of trace elements in edible mushrooms collected in diffrent plots. During statistical analyses we investigated how environmental factors affect the concentration of these elements