Dynamics of Lobaria pulmonaria (L.) Hoffm. cenopopulations near its northern distribution boundary in Paanajärvi National Park old-growth forests, Russia

Abstract The population dynamics of the epiphytic lichen Lobaria pulmonaria were studied in spruce forests within Paanajärvi National Park (Karelia), which has seen no major disturbances during the last 190 to 270 years. Studies for the period 2015–2021 showed a rise in thallus number and area, with a larger proportion in the ontogenetic spectrum being young, non-reproductive thalli (virginal 1). Sexual reproduction was low, with fertile thalli comprising less than 1% of the total. Salix caprea and Populus tremula trunks served as the main growth surfaces for Lobaria pulmonaria in the northern taiga forests. Furthermore, Salix caprea offered the optimal environment for thalli to grow and develop. In a few instances, the colonization of new substrata was observed. Climate change is expected to have a positive impact, allowing the species’ range expansion at its northern border.