Biological and environmental characteristics of three cosmopolitan mosses dominant in continental Antarctica
Article first published online: 24 FEB 2009
1999 IAVS - the International Association of Vegetation Science
Journal of Vegetation Science
Volume 10, Issue 2, pages 231–242, April 1999
How to Cite
Lewis Smith, R.I. (1999), Biological and environmental characteristics of three cosmopolitan mosses dominant in continental Antarctica. Journal of Vegetation Science, 10: 231–242. doi: 10.2307/3237144
- Issue published online: 24 FEB 2009
- Article first published online: 24 FEB 2009
- Received 22 August 1997; Revision received 27 March 1998; Final revision received 30 June 1998; Accepted 30 June 1998.
- Bryum argenteum;
- Bryum pseudotriquetrum;
- Ceratodon purpureus;
- Hydrological gradient;
Abstract. Bryum argenteum, B. pseudotriquetrum and Ceratodon purpureus are the predominant mosses in Victoria Land, continental Antarctica. All have cosmopolitan distributions and are widespread throughout Antarctica with wide ecological amplitudes resulting in considerable morphological variation. They are well adapted to tolerate the physiological stresses imposed by the severe environment. This study investigates aspects of their growth, physiology and survival in response to habitat constraints, especially hydrology. Their distribution is controlled almost exclusively by moisture availability. Each species tends to predominate in a specific zone along hydrological gradients, with B. pseudotriquetrum on moist soil, C. purpureus on drier soil, and B. argenteum on unstable stream margins, fluvial deposits and the marginal capillary zone. Where conditions are optimal, each species can form a turf 6–10 cm thick. Nutrient status of the soil does not appear to be an important determinant in the distribution pattern within communities. The thermal regime of the moss turf varies according to its moisture content; for a period of ca. six weeks during the summer, with the frequent long spells of 24-h sunshine, temperatures remain above 0 °C for much of the time even though air temperatures are frequently below the freezing point. This allows growth and metabolic activity to proceed continuously at a relatively rapid rate for quite long periods. Annual shoot incremental growth can exceed 3.5 mm in each species. Growth of B. argenteum may be inhibited by UV- B radiation. The optimal temperature for photosynthesis in each species is around 15 °C, but significant carbon fixation occurs at 5 °C. Photosynthetic rates at 5, 10 and 20 °C were B. argenteum > B. pseudotriquetrum > C. purpureus.