Photosynthesis of widespread lichen species in pine forests of Central Siberia

Abstract

Lichens and other terrestrial photosynthetic unicellular organisms of the planet consume nearly 14.3 billion tons of atmospheric CO2. Due to climate change, such important components of the forest ground cover as lichens are very vulnerable. This study evaluates the photosynthetic activity in widespread lichens by measuring the indices of net photosynthesis, dark respiration, and prompt fluorescence. Hence, cryptogams of pine forests in Central Siberia near the Zotino tall tower observatory (ZOTTO) are characterized as highly active. Cladonia stellaris (Opiz.) Brodo and Cladonia rangiferina (L.) are the main representatives of ground cover species. The purpose of this study was to determine the photosynthetic activity in dominant species of ground cover lichens during a growing season. We found the seasonal dynamics of photosynthesis with the lowest values being observed in June, and the highest ones in August. Dark respiration peaks in June and is the lowest in September. Fluorescence values are within the range of 6.7 ± 0.3. The species under study that grow on podzol soils in pine forests show fast kinetic activation.