Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- I Introductory Chapters
- II Ecophysiology
- III Aquatic Bryophytes
- 6 Ecological and Physiological Effects of Changing Climate on Aquatic Bryophytes
- 7 Aquatic Bryophytes under Ultraviolet Radiation
- IV Desert and Tropical Ecosystems
- V Alpine, Arctic, and Antarctic Ecosystems
- VI Sphagnum and Peatlands
- VII Changes in Bryophyte Distribution with Climate Change: Data and Models
- VIII Conclusions
- Index
- References
7 - Aquatic Bryophytes under Ultraviolet Radiation
Published online by Cambridge University Press: 05 October 2012
- Frontmatter
- Contents
- List of contributors
- Preface
- I Introductory Chapters
- II Ecophysiology
- III Aquatic Bryophytes
- 6 Ecological and Physiological Effects of Changing Climate on Aquatic Bryophytes
- 7 Aquatic Bryophytes under Ultraviolet Radiation
- IV Desert and Tropical Ecosystems
- V Alpine, Arctic, and Antarctic Ecosystems
- VI Sphagnum and Peatlands
- VII Changes in Bryophyte Distribution with Climate Change: Data and Models
- VIII Conclusions
- Index
- References
Summary
Introduction
Ultraviolet radiation (UVR) has many effects on photosynthetic organisms. It is a minority component (about 6%) of solar radiation in comparison with the dominant visible/photosynthetic and infrared bands. However, UVR is a natural environmental factor that has been involved in the appearance of diverse adaptive changes in organisms through the development of life on Earth (Cockell & Knowland 1999). UVR induces a number of biological processes in all living organisms, including humans, and many of them are harmful. In this respect, among the three wavelength categories into which UVR is divided by the CIE (Commission Internationale d'Eclairage), the most damaging UV-C (< 280 nm) is not relevant at the present time because of its complete absorption by stratospheric oxygen and ozone, but both UV-B (280–315 nm) and UV-A (315–400 nm) penetrate the biosphere and have significant biological effects. These effects are highly dependent on wavelength, and different biological weighting functions have been conceived to calculate the biologically effective UV (UVBE). UVBE encompasses UV-A and UV-B. However, given the logarithmic increase in effectiveness with decreasing wavelength, UVBE is dominated by UV-B, especially at shorter wavelengths. Therefore, most studies on the effects of UVR have dealt with UV-B. This has been especially true since the discovery of the anthropogenic stratospheric ozone reduction, because UV-B (and not UV-A) is absorbed by stratospheric ozone, and thus ozone reduction leads to an increase in surface UV-B levels.
- Type
- Chapter
- Information
- Bryophyte Ecology and Climate Change , pp. 115 - 146Publisher: Cambridge University PressPrint publication year: 2011
References
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