Lichens Parmelia sulcata/ time response model to environmental elemental availability

Parmelia sulcata transplants, collected in a non-polluted area, were exposed to new atmospheric conditions at six stations, of which five were located near power plants and one at an unpolluted area. Data were collected for a 1-year period, on rainfall, airborne particulates, elemental deposition and on lichen elemental composition. The study was carried out to quantify the relationships between elemental availability and elemental accumulation in lichens. A mathematical model was developed, involving a simple representation of the lichen, and a memory loss function which describes the time relations for the lichen’s progressive representation of its new ambient conditions. The collected data set was used to test the model. The results indicate that the environmental data on Na, Al and Pb could be reproduced and predicted by the model, including the variability patterns. Half-memory times were calculated for Na, Al and Pb as 200, 500 and 600 days, respectively, based on using all station data. However, further improvements are still needed, including the clarification of differences in model outcomes between stations