Lichens as Air Pollution Biomonitors in a Semiarid Environment in Idaho

Rope, Susan; Pearson, Lorentz

Two measurement techniques were employed to evaluate the feasibility of using lichens as in situ biomonitors of atmospheric pollution in a semiarid climate—trace element analysis and electrolyte leakage from cells. Trace element concentrations were generally higher in Lecanora melanophthalma Ram. tissues than previously measured in sagebrush and perennial grasses from the same locations, but lower than in soil. Lichens from an urban area (Idaho Falls) had statistically higher concentrations of ten elements, particularly lead and zinc, than those from the INEL and CRMO. Electrolyte leakage was greatest from thalli collected in the nighttime downwind direction from the ICPP, even though daytime winds, which blow in the opposite direction, are more frequent, suggesting that in a semiarid climate, injury from atmospheric SO2 and NOX pollution in lichen tissues is greatest when the thalli are moist frommorning dew or other sources. These results demonstrate that some lichen species, especially Lecanora melanophthalma, have potential for biomonitoring of atmospheric pollutants in the semiarid regions of the Intermountain West.