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Elemental composition of Usnea sp lichen from Potter Peninsula, 25 de Mayo (King George) Island, Antarctica
2016
Bubach, Débora | Catán, Soledad Perez | Di Fonzo, Carla | Dopchiz, Laura | Arribére, Maria | Ansaldo, Martin
Several pollutants, which include metals, are present in the Antarctic atmosphere, snow, marine and terrestrial organisms. This work reports the elements incorporated by Usnea sp thalli in Potter Peninsula, 25 de Mayo (King George) Island, South Shetlands, Antarctica. Geological origin was analyzed as possible sources of elements. For this purpose, correlations were done using a geochemical tracer, principal component analysis and enrichment factors were computed. Lithophile elements from particulate matter were present in most of the sampling sites. Bromine, Se and Hg showed the highest enrichment factors suggesting other sources than the particulate matter. Mercury values found in Usnea sp were in the same range as those reported for Deception Island (South Shetlands) and remote areas from the Patagonia Andes.
Show more [+] Less [-]Effects of the urban environmental conditions on the physiology of lichen and moss
2016
Sujetovienė, Gintarė | Galinytė, Vilma
The lichen Evernia prunastri (L.) Ach. and the moss Ptilium crista-castrensis (Hedw.) DeNot were exposed in three different urban sites along with the different pollution loads in order to evaluate the environmental quality. Physiological changes after the exposition were assessed by evaluating the content of photosynthetic pigments, chlorophyll fluorescence, membrane lipid peroxidation and integrity of cell membranes. The differences in response of fluorescence, chlorophylls contents and injuries of cell membranes were observed between the two species and between the sites. E. prunastri showed a great capacity to sustain the photosynthesis processes in the urban environment, while this capacity was very low in the transplanted moss P. crista-castrensis. The levels of malondialdehyde (MDA) indicated a significantly higher oxidative stress in the transplants at urban and residential sites. The integrity of cell membranes in moss samples was also more damaged than in lichen.
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