Reconstructing Air Pollution Trends in Remote Forests of Central Europe Using Lichen Herbarium Specimens

Lichen collections may contribute to a better understanding of past environmental conditions. By analysing herbarium specimens and recently collected material of the lichen Lobaria pulmonaria, this study reconstructs six decades (1960-2022) of air quality changes in remote forests of Central Europe (the Western Carpathians). Twenty specimens were selected for retrospective analysis of major and trace elements (Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, S, Sb, and Zn), focusing on both historical and current background concentrations. The results revealed peaks of potentially toxic elements (As, Fe, Hg, Mn, Ni, S, and Sb) up to 1989, with a progressive decline observed thereafter, particularly for Pb following the introduction of unleaded gasoline. Background element concentrations from 1960 to 1989 were at least four times higher than actual levels. The study highlights the value of herbarium collections for reconstructing air pollution history and tracking changes in background element concentrations in remote areas, particularly when alternative data sources are unavailable. It also addresses both the opportunities and limitations of this approach.