Long-term impacts of simulated climatic change on secondary metabolism, thallus structure and nitrogen fixation activity in two cyanolichens from the Arctic
Article first published online: 18 JUN 2003
Volume 159, Issue 2, pages 361–367, August 2003
How to Cite
Bjerke, J. W., Zielke, M. and Solheim, B. (2003), Long-term impacts of simulated climatic change on secondary metabolism, thallus structure and nitrogen fixation activity in two cyanolichens from the Arctic. New Phytologist, 159: 361–367. doi: 10.1046/j.1469-8137.2003.00812.x
- Issue published online: 18 JUN 2003
- Article first published online: 18 JUN 2003
- Received: 9 April 2003 Accepted: 24 April 2003; doi: 10.1046/j.1469-8137.2003.00812.x
- nitrogen fixation;
- the Arctic
- •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.