Application of Optical Spectroscopy for the Analysis of Physiological Characteristics and Elemental Composition of Lichens of the Genus Hypogymnia with Different Degrees of Anthropotolerance

Abstract

The main physiological and biochemical characteristics and elemental composition of three lichen species of the genus Hypogymnia (Nyl.) Nyl. in one habitat were studied using spectroscopic methods. The model species were placed in the following order of decreasing degree of anthropotolerance: H. physodes (L.) Nyl. → H. tubulosa (Schaer.) Hav. → H. vittata (Ach.) Parrique. The contents of chlorophylls a and b, phenolic compounds, pheophytinization quotient, and antiradical activity were determined by a spectrophotometric method. The antioxidant activity was determined by an amperometric method. The physiological and biochemical parameters for each of the three species corresponded to those for background ecotopes. These parameters and the integrity of the system of correlations between the parameters were lower in species with a low degree of anthropotolerance. Twenty-three elements were found in thalli of the model species using atomic emission spectroscopy with inductively coupled plasma. They included macro- and microelements, heavy metals, and metalloids. The maximum concentrations of most elements were found in H. vittata; the minimum concentrations, in H. physodes. An analysis of the interaction between the physiological and biochemical characteristics and the contents of the elements indicated the presence of a complex system of correlations in each species. Differences in this system of correlations may have been due to the specific composition of secondary metabolites, which determine the features of adaptive reactions. The use of various optical spectroscopy methods enabled an evaluation of not only the functional specificity of the studied species but also its connection to their anthropotolerance level. Low resistance to anthropogenic influences was combined with lower coordination of physiological and biochemical characteristics and low integrity of the system of correlations. The most vulnerable species H. vittata had the minimal values of the main functional parameters, a poorer correlation of them with the elemental composition, and higher concentrations of some toxic elements. The use of a complex analysis of the physiological and biochemical characteristics and elemental compositions using various spectral methods was crucial for the bioindication and ecological physiology of lichens.