Submersion tolerance in a habitat of Stereocaulon paschale (Stereocaulaceae) and Cladonia stellaris (Cladoniaceae) from the high mountain region Rondane, Norway
Sadowsky, Andres; Hussner, Andreas; Ott, Sieglinde
The Holarctic fruticose lichen Stereocaulon paschale is known to be capable of tolerating at least six weeks of constant submersion under natural conditions in a meltwater pool at about 1000 m above sea level in Rondane in eastern Norway. Its adaptations to temporary submergence involve both physiology and anatomy, differing fundamentally from Cladonia stellaris, the dominant lichen species in the adjacent terrestrial habitat. Comparison of two populations of Stereocaulon paschalefrom the melt water pool and from a dry forest habitat revealed significant physiological differences between them in oxygen uptake and the photosynthetic process. We discuss the role of cephalodia and thallus structure, focusing on gas exchange and water relations.