CONICET | Buscador de Institutos y Recursos Humanos

Lichenized fungi are widely used as biomonitors. Some species, like Ramalina celastri, may be useful as bioindicators of air pollution. To evaluate the response of this species to the impact of agriculture, in situ samples thallus growing on fences rods (about ten years of installation) they were taken. Two crops conditions were analyzed: soybean with agrochemicals and organic soybean (without agrochemical). A third condition, away from 500 m of the crops and separate from them by a native forest as a control. The election of the species is because is the only one growing on fences while in the control site there are more species in addition to R. celastri. The fence is ten years old. The samples were collected along a hundred meters for each condition, in the face of the fence who is looking to the crop and in the same orientation. For each sample chlorophyll concentrations (Chlor. a, Chlor. b, Chlor. Total), phaeophytin (Phaeoph. a, Phaeoph. b, Phaeoph. Total.), HPCD (hydroperoxy conjugated dienes) and soluble proteins were determined. Moreover, the indexes Chlor. b/Chlor. a y Phaeoph. a/Chlor. a were calculated. Data were analyzed with Infostat. The results showed that under both conditions of crops there were more contents of pigments (chlorophyll and phaeophytyn) regarding the control condition, may be due to light and temperature conditions. Also, there were found highest values of Chlor. b/ Chlor. a, Phaeoph. a/Chlor. a indexes, HPCD content, and protein in crop condition. These parameters are markers of stress in lichens and its growth indicates environmental perturbations effects on the ecosystem. Therefore, in agricultural areas, R. celastri manifests as a tolerant species, despite of stress evidences it is the only one that grows in fences. Since biomarkers showed no differential response between the two crops conditions, it follows that R celastri is not measurably affected by the fumigation of them.