HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY OF PHENOLICS IN RECENT AND SUBFOSSIL LICHENS

Subfossils of the lichens Umbilicaria krascheninnikovii (Sav.) Zahlbr. and Umbilicaria hyperborea (Ach.) Hoffm. were discovered after they w ere exposed by ice melt in Greenland. Extracellular phenolic substance s of emerging lichens were analyzed by high performance liquid chromat ography and compared with those found in lichens of the same species t hat escaped glaciation. All major and minor phenolics of living lichen s were present in subfossils. although significantly lower amounts of the major constituent, gyrophoric acid, were documented. After being s ubjected to experimental pressure treatments in a hydraulic press, Umb ilicaria nammulata (Ach) Tuck. thalli showed highly significant reduct ions in the levels of both gyrophoric acid and lecanoric acid, and the decrease was more pronounced under the more severe of two pressure tr eatments. The decrease in mean phenolic content following immersion in water for 5 days was not statistically significant. There was a consi derable range of phenolic concentrations among thalli of modern arctic specimens of Umbilicaria as well as among thalli recently released fr om ice, and the variance in subfossils was not significantly different from that in living populations.