Evaluation of dispersal volcanic products of recent events in lichens in environmental gradient, Nahuel Huapi National Park, Argentina.

The atmospheric transport of volcanic products are subject to several variables, mainly the height of the eruption column and wind direction, thus elements associated with the ashes are deposited in major or lesser degree depending on variables as latitude, wind and humidity. The lichens are able to reflect the atmospheric fallout. The present work evaluated the correlation between meteorological parameters, geographic locations, sulphur and other element concentrations in lichens genus Usnea affected by Puyehue-Cordón Caulle complex (North Patagonia Andean Range) eruption of June 4, 2011. Semiquantitative analyses of biological elements by scanning electron microscope methods, sulphur (S) by LECO and other elements by instrumental neutron activation were evaluated by principal component analysis. Elements as antimony, arsenic, barium, bromine, calcium, caesium, potassium, rubidium, selenium, and uranium correlated with distance to volcano, also calcium and potassium with longitude while bromine, rubidium, and potassium with humidity. Those results indicate that Usnea sp. is a good bioindicator of the atmospheric volcanic emissions in relation to environmental gradient.