Variations in metal levels accumulated in Poison Pax (Paxillus involutus) mushroom collected at one site over four years.

K, Ca, Mg, Na, Zn, Al, Fe, Mn, Rb, Cu, Sr, Ag, Ba, Pb, Ni, Cd, Co, Cr and Hg content have been examined in caps and stipes of mature fruiting bodies of Poison Pax (Paxillus involutus) collected from the same site over 4 years in 1999-2002. Cluster analysis (CA) did indicate on a different composition of these mineral constituents in fruiting bodies that emerged in 1999 and 2000, when compared to 2001 and 2002. In light of principal component analysis (PCA), the metals differentiating these two biannual sets of fruiting bodies were Mn (greatest load to PC1) together with Ca, Fe, Al, Cu, Cd and Hg; Ni (greatest load to PC2) together with Zn, Sr, Ba, Pb and Co, and Ag (greatest load to PC3) together with Na. The elements such as Mg, Sr and Cr showed similar contents both in caps and stipes over four years (p > 0.05; U Mann-Whitney test). Depending on a year or years of collection, contents fluctuated (p < 0.05) for K, Ca, Zn, Al, Fe, Mn, Na, Rb, Cu, Ag, Ba, Pb, Ni, Cd, Co and Hg. The values of quotients for K, Ca, Mg, Na, Al, Ba, Rb, Cu, Sr, Mn, Co, Cr and Ni content between caps and stipes (Q(C/S)) remained constant (p > 0.05) over four years, and for Fe, Ag, Cd, Cr, Hg and Pb fluctuated (p < 0.05). The results of this study imply that a potential of mycelium to up-take metallic elements from substratum and their further transportation within fruiting body and sequestration in Poison Pax, even at a stabile geochemical condition (the same stand and probably the same mycelia), can fluctuate over the years or the life-span of mycelium.