Long‐term impacts of simulated climatic change on secondary metabolism, thallus structure and nitrogen fixation activity in two cyanolichens from the Arctic

Abstract

Summary• Although the most pronounced effects of stratospheric ozone depletion and climate warming probably will occur in polar regions, arctic lichens have not been much studied in relation to climate change.• Samples of two arctic cyanolichens of the genus Peltigera , exposed in situ to ambient and enhanced UV-B radiation and ambient and increased temperatures, were collected in 2001, 5 yr after the establishment of the experimental set-up. Thallus dimensions and size, coverage of soralia, nitrogen fixation activity and levels of UV-C-absorbing substances were measured.• Warming had pronounced positive effects on the tridepsides methyl gyrophorate and gyrophoric acid, and unidentified trace substances. However, the combination of enhanced UV-B and increased temperatures did not lead to higher than control levels. Warming reduced coverage of soralia. There were no significant treatment effects on thallus size, dimensions and nitrogen fixation activity.• UV-B radiation did not to have any adverse effects. The accumulation of tridepsides with warming may be related to increased activity of pathogenic microorganisms or insect herbivores.

Lichen bioindication of biodiversity, air quality, and climate: baseline results from monitoring in Washington, Oregon, and California.

“…48), and Pseudocyphellaria anomala are all associated with the montane climate regime (Geiser and Neitlich 2007). Owing to their unique physiology, lichens in this group are renowned for their susceptibility to both thermal and moisture stress (Bjerke et al 2003, Geiser and Neitlich 2007, Nash and Olafsen 1995, Richardson and Cameron 2004. Cyanolichens are intimately linked to forest health in the Pacific Northwest because of their contribution to nitrogen budgets and nutrient cycling.…”

Influence of sun irradiance and water availability on lichen photosynthetic pigments during a Mediterranean summer

“…Temperature may directly or indirectly affect lichens: for example, exposures to increasing temperatures induced a reduction of the chlorophyll content in L. pulmonaria and Evernia prunastri (Gauslaa & Solhaug 1999;Pisani et al 2007) and high temperature affects the biosynthesis of lichen substances (Bjerke et al 2003).…”

Effect of Environmental Change on Secondary Metabolite Production in Lichen-Forming Fungi

“…Since many lichen compounds absorb UV-B (Solhaug et al, 2003) an increase in production of those compounds is expected with continued climate change. Bjerke et al (2003) showed an increase in the levels of two tridepsides (methyl gyrophorate and gyrophoric acid) and unidentified trace metabolites after a five-year study of two arctic lichen species of Peltigera.…”