Lichens and Mosses Used as Biomonitors in Environmental Magnetic Studies
Abstract
Plants are widely used in classical biomonitoring studies, due to the ability of different vegetation species to accumulate dust and toxic elements in their tissues or to bound them to surface structures. The aim of the present investigation is to study magnetic signature of foliose and fruticose lichens and mosses, gathered from several polluted and clean sites in Bulgaria and to evaluate their suitability as enviromagnetic indicators. Plant material was sampled from rocks and tree branches. Various species demonstrate different preferences in grain size distribution of accumulated dust particles. Measurements of magnetic susceptibility, acquisition of isothermal remanence, anhysteretic remanence and hysteresis loops reveal that lichens preferentially accumulate coarser anthropogenic grains as compared to the magnetic fraction in clean localities. This suggests that conclusions related to grain size distribution of industrial emissions should be carefully considered in respect to bioindicator used in each particular study. The main ferromagnetic phase in accumulated dust from various vegetation species is magnetite-like with possible Al-, Si- and Mn-substitutions, related to the specific chemistry of source emissions. This phase has varying grain size distribution, deduced by dP parameter from fitted Gausian functions to IRM-acquisition curves and shows inverse relationship to the remanent coercivity of the soft IRM component. It is probably related to sorting effect with distance and the presence of single/multiple pollution sources.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2009
- Bibcode:
- 2009AGUSMGP11H..01J
- Keywords:
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- 1512 Environmental magnetism;
- 1519 Magnetic mineralogy and petrology;
- 1540 Rock and mineral magnetism