The Use of Lichens and Mosses to Monitor Trace Element Pollution in Slovenia

Abstract

One way to determine the levels of trace elements in the atmosphere is the use of suitable biomonitors such as lichens and mosses. These organisms, although neither evolutionarily nor taxonomically related, have some common characteristics, which enable them to be used as monitors for atmospheric pollution. Both have a high accumulation ability for dissolved substances based mainly on their ion-exchange properties and the fact that they have no protective organs such as a cuticle or waxy surface. They also lack roots and are thus strongly dependent for their mineral nutrients on material deposited through wet and dry deposition on tiie plant surface. However, the influence of the substrate on which these organisms grow, as a source of elements, could not be neglected [1]. Furthermore, since lichens and mosses have a high surface to mass ratio they are highly effective as filters for airborne particulates with their attached atmospheric pollutants such as trace elements and radionuclides, as well as for soil or rock dust particles carried by the wind [2, 3]. Numerous national and international studies have been performed using one of these organisms to monitor trace element deposition [4–6]. Two national surveys using biomonitors to monitor atmospheric trace element and radionuclide deposition have been performed in Slovenia. Namely in 1992, the epiphytic lichen Hypogymnia physodes was collected at 86 sampling points of the regular bioindication grid and in 1995 moss samples (Pleurozium schreberi and Hypnum cupressiforme) were sampled at 33 selected locations of the same bioindication grid as a part of the international project known as Atmopheric Heavy Metal Deposition in Europe [7,8].