Growth and age assessment of epilithic lichen Protoparmeliopsis muralis (Schreb.) M. Choisy in Southern Karelia

The paper presents the results of studying the growth characteristics and age estimation of the thallii of the epilithic lichen Protoparmeliopsis muralis (Schreb.) M. Choisy on the coastal diabases of the Suna River ("Kivach" reserve) in the taiga zone of the Republic of Karelia. The size (area of tallii ) and growth of 17 talluses of this type over an 11-year period (2007-2018) were analyzed . The dimensions of the thallii were within the range of 1.17...26.39 cm2. Only linear growth was observed in the studied size range. There was a significant variation in the growth rate of the studied thallii under these conditions-0.20...1.50 cm2 per year, due to individual characteristics of thallii, intraspecific and interspecific competition, as well as environmental conditions. The growth duration of thallii in the studied size range was estimated: 6...23 years.