Accumulation of lead by the lichen

Summary The lichen Stereocaulon dactylophyllum,occurring on a metalliferous spoil tip, was found to accumulate various elements within parts of the apothecium, such as the subhymenium and the fertile hymenium. The hymenium was particularly contaminated by lead, and this may subsequently affect ascospore viability. Certain elements were present on the external surface of the thalli and apothecia; the percentage composition of the elements within the apothecium differed from that on the outside of the apothecium. Fourteen elements were recorded from samples of the metalliferous spoil, the subhymenium and the hymenium; the ranking of elements varied in the samples as also did the percentage contributions of the various elements. The lichen is an important accumulator of elements derived from various sources, including the atmospheric transport of particulates emanating from the spoil tip. It may be speculated that the elements, including the toxic ones, will subsequently be accumulated within organisms belonging to various trophic levels; rotifers which are present on both the apothecia and thalli are likely to be affected. Dr F. Brian Pyatt is Head of the Ecology Section in the Department of Life Sciences at Nottingham Polytechnic, where Mr D. Lacy is a member of the Department of Chemistry and Physics. Mr E.H. Beaumont was until recently in the Department of Zoology at the University of Oxford, and Mr D.M. Storey is a member of the Department of Biological Sciences at the University of Salford, UK.