Development and calibration of epiphytic lichens as saltfall biomonitors—dry-deposition modelling

• Published in: Environmental pollution (1987) 2002-01, Vol.120 (1), p.69-78
• Main Authors: Figueira, Rui, Pacheco, Adriano M.G., Sousa, António J., Catarino, Fernando
• Format: Article
• Language: English
• Subjects: Analysis methods; Animal, plant and microbial ecology; Applied ecology; Applied sciences; Atmospheric deposition; Atmospheric pollution; Biological and medical sciences; Biomonitoring; Calibration; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; Environmental Monitoring - methods; Environmental Monitoring - statistics & numerical data; Exact sciences and technology; Forecasting; Fundamental and applied biological sciences. Psychology; Lichen transplants; Lichens - chemistry; Models, Theoretical; Pollution; Precipitation; Rain; Sodium Chloride - analysis; Sodium Chloride - pharmacokinetics; Tropospheric salinity
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/S0269-7491(02)00129-X

The concentration of saline elements measured in lichens was calibrated against dry deposition. Lichen transplants ( Ramalina calicaris and Usnea spp.) were investigated as biomonitors of the atmospheric deposition of marine salt, and a calibration model was set up to predict the dry deposition of saline elements from the concentration of salt tracers in lichens. The study was performed in the Portuguese Atlantic coast, where a monthly transplantation program was run in two stations that show clear differences in terms of precipitation regimes. At both stations, dry deposition and precipitation records were kept for the whole duration of the program. General trends in results have indicated that rainwater may wash saline elements out of lichens, though such an effect does not appear to be linear. A multiple-regression approach was taken to look for a calibration between dry-deposition fluxes and lichen concentrations through a stepwise technique. The calibration model for data obtained in both stations features two break points that define precipitation ranges for low, moderate and heavy rain conditions. The results show that lichens can really be used to indicate the dry deposition of sea salt.