Any Way the Wind Blows Does Really Matter in Lichen Response to Air Pollution from an Oil Refinery

Lichens serve as effective bioindicators for air pollution studies, yet most biomonitoring research focuses primarily on the distance from pollution sources, often neglecting wind data that could elucidate the spread of airborne pollutants. In our previous study in Slavonski Brod, Croatia, we utilized data from a monitoring station, emphasizing the impact of meteorological conditions, particularly wind, on the dispersal of pollutants from a neighbouring oil refinery. To gain a deeper understanding of air pollution dynamics, here, we studied lichen vitality-measured through photochemical efficiency and photosynthetic pigments-alongside the metal (Ni, Zn, Cd, Pb) and non-metal (sulphur and nitrogen) content in native lichen species Flavoparmelia caperata across 17 plots within a 20 km radius of the refinery. Our analysis employed generalized linear models (GLMs) to incorporate various environmental predictors, including distance from the refinery, direction-specific wind speed and frequency, vegetation density, and the orientation of lichen samples with respect to north and the refinery. Findings show that pollution levels are significantly influenced, not only by distance but also by direction-specific wind patterns, underscoring the necessity of including these variables in future biomonitoring studies and highlighting a critical need for air quality management interventions.