Data on the elemental composition of lichens in the landscapes of the Central Siberian taiga
The elemental composition of lichens was identified to assess ground-level air in the landscapes of the Siberian taiga which form the ecological framework of Northern Eurasia. The samples were collected in multiple locations in the southeastern part of the Central Siberian State Biosphere Reserve (CSSBR), mainly along the river valleys. This territory represents the background conditions due to its protected status. The territory is confined to the lower part of the catchment area of the Podkamennaya Tunguska River in the Evenki Municipal District of the Krasnoyarsk Territory. The samples were collected from thin branches of coniferous trees at a height of 1.5–2 m above the day-surface level from at least 10 adjacent trees within the individual areas of 10 to 20 m2 and then mixed to form composite samples for each area. To avoid contamination, the samples were placed in clean plastic bags using plastic gloves. The sampling points were linked to the coordinate system using a GPS receiver which allowed conducting repeated studies. The samples were dried at 40°C and foreign material (e.g., fragments of other plants) was removed using plastic tweezers. Then, the samples were ground in an agate mortar, and their aliquots were digested with a mixture of nitric and fluorhydric acids and hydrogen peroxide. The elemental composition of solutions was identified by two methods, namely, inductively coupled plasma atomic emission spectroscopy and inductively coupled plasma mass spectrometry. Ten samples of epiphytic fruticose lichens of the genera Bryoria (Bryoria fuscescens), Evernia (E. mesomorpha), Usnea (U. glabrescens), Ramalina (R. thrausta) and five samples of epiphytic lichens of the genera Cladonia (C. arbuscular, C. rangiferina, C. amaurocraea) were analyzed. Thus, it was possible to obtain statistically significant data on the content of 60 elements, including heavy metals (Li, Be, B, Na, Mg, Al, P, S, K, Ca, Sc, Ti, U, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb , Sr, Y, Mo, Rh, Pd, Ag, Cd, Sn, Sb, Te, Sc, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb , Lu, Re, Ir, Pt, Au, Hg, Tl, Pb, Bi, Th, U), under background conditions of the Central Siberian taiga for southwestern Evenkia.