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.

本研究通过测定地衣的元素组成，以评估构成北欧亚大陆生态框架的西伯利亚泰加林景观的近地面大气质量。
样本采集于中央西伯利亚国家生物圈保护区（Central Siberian State Biosphere Reserve, CSSBR）东南部的多个点位，主要沿河谷布设。该保护区因受严格保护，其环境代表了自然背景状态，研究区域位于克拉斯诺亚尔斯克边疆区埃文基自治区的石泉通古斯河（Podkamennaya Tunguska River）流域下游区段。
样本采集自针叶树的细枝，采样高度距地面1.5~2米：在每个10~20平方米的样区内，从至少10株相邻树木上采集样品并混合，制成该样区的复合样本。为避免污染，采样时需佩戴塑料手套，将样品装入洁净的塑料袋中。
采样点位通过GPS接收机进行坐标定位，以支持后续重复研究。样品在40℃下烘干，并用塑料镊子剔除其中的外来杂质，例如其他植物碎屑。随后将样品置于玛瑙研钵中研磨，分取部分试样采用硝酸、氢氟酸与过氧化氢的混合体系进行消解。
采用电感耦合等离子体原子发射光谱法（inductively coupled plasma atomic emission spectroscopy）与电感耦合等离子体质谱法（inductively coupled plasma mass spectrometry）两种方法，对消解液的元素组成进行测定。
本次分析共包含10份树附生枝状地衣样本，涵盖树花属（*Bryoria*，含*Bryoria fuscescens*）、扁枝衣属（*Evernia*，含*E. mesomorpha*）、松萝属（*Usnea*，含*U. glabrescens*）及枝衣属（*Ramalina*，含*R. thrausta*）；另有5份树附生地衣样本，来自石蕊属（*Cladonia*，含*C. arbuscular*、*C. rangiferina*、*C. amaurocraea*）。
最终，本研究获取了西伯利亚泰加林背景条件下埃文基自治区西南部区域60种元素的含量数据，涵盖锂（Li）、铍（Be）、硼（B）、钠（Na）、镁（Mg）、铝（Al）、磷（P）、硫（S）、钾（K）、钙（Ca）、钪（Sc）、钛（Ti）、铀（U）、铬（Cr）、锰（Mn）、铁（Fe）、钴（Co）、镍（Ni）、铜（Cu）、锌（Zn）、镓（Ga）、砷（As）、硒（Se）、铷（Rb）、锶（Sr）、钇（Y）、钼（Mo）、铑（Rh）、钯（Pd）、银（Ag）、镉（Cd）、锡（Sn）、锑（Sb）、碲（Te）、钪（Sc）、钡（Ba）、镧（La）、铈（Ce）、镨（Pr）、钕（Nd）、钐（Sm）、铕（Eu）、钆（Gd）、铽（Tb）、镝（Dy）、钬（Ho）、铒（Er）、铥（Tm）、镱（Yb）、镥（Lu）、铼（Re）、铱（Ir）、铂（Pt）、金（Au）、汞（Hg）、铊（Tl）、铅（Pb）、铋（Bi）、钍（Th）、铀（U），其中包含多种重金属元素，且该数据具有统计学显著性意义。