Structural and functional adaptations of epilithic lichens of Umbilicaria genus in the White Sea coastal conditions

Abstract

Anatomical and physiological characteristics (width of anatomical layers and the amount of photosynthetic pigments) of two epilithic lichen species Umbilicaria torrefacta (Lightf.) Schrader and U. deusta (L.) have been studied. The study took place on the supralittoral zone on the coast of the White Sea in two points: Kolezhma village and Keret village in 2014 and 2015. Ecological plasticity of mycobiont which contacts the environment and gives a niche to the photobiont have been revealed, based on the analysis of variance in the study of anatomical structures of two different types of habitats and between different samples of the same species. Coastal conditions provide favorable levels of humidity and light for the U. torrefacta and U. deusta species. This allows symbiotic organism to maintain a symbiotrophic balance due to the plasticity of the fungal symbiont which contacts the abiotic environment. At the same time these adaptation mechanisms do not include functional changes, such as photosynthetic apparatus of the autotrophic symbiont, conditions for which are set by the fungal organism. U. deusta and U. torrefacta species only show structural adaptations-the adaptations that follow the path of anatomical structure changes and the relative stability of the physiological parameters. The study shows that anatomical structure of thalli varies more significantly between the two species than within samples of the same species.

Coastal Lichens

“…Species of the genus Wahlenbergiella occur in the littoral zone of the Northern Hemisphere (Gueidan et al 2009), and the species Verrucaria serpuloides in the Southern Hemisphere grows constantly submerged in seawater (Lamb 1973), while species of Hydropunctaria mainly occur in the supralittoral zone above the periodic flooding zone (Gueidan et al 2009;Orange 2012). Some lichen species are not typical coastal species and widely distributed both on the terrestrial area and on the coasts, such as Xanthoria parietina (Hawksworth 2000), and species of the genus Umbilicaria, which successfully colonize also stones and rocks in forest communities, on the shores of lakes and rivers (Markovskaya et al 2010;Sonina 2014;Sonina and Tsunskaya 2016;Sonina et al 2017). It remains unclear what features determine the distribution in such different habitats.…”

“…Structural and functional adaptations. Structural and functional studies of coastal lichen species were carried out on the White Sea coast (Sonina and Tsunskaya 2016;Sonina et al 2017). The objects of these studies were species of the genus Umbilicaria and species Physcia caesia and P. dubia which belong to the non-halophytic group and occurred in zones 3 and 4 ( Figs.…”

Comparative study of structural and ecophysiological features of lichens of different ecological groups in rocky forest communities of northernmost boreal zone (Karelia, Russia)

“…To study anatomical characteristics of thallus, standard methods of optical microscopy were used (see Sonina et Tsunskaya 2016). Anatomical features of thalli were studied using a light microscope (Axio Scope A1, Carl Zeiss, Germany).…”