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Influence on photosynthesis of starlight, moonlight, planetlight, and light pollution (reflections on photosynthetically active radiation in the universe)

Raven, J. A. and Cockell, C. S. (2006). Influence on photosynthesis of starlight, moonlight, planetlight, and light pollution (reflections on photosynthetically active radiation in the universe). Astrobiology, 6(4) pp. 668–675.

DOI (Digital Object Identifier) Link: http://dx.doi.org/10.1089/ast.2006.6.668
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Abstract

Photosynthesis on Earth can occur in a diversity of organisms in the photosynthetically active radiation (PAR) range of 10 nmol of photons m-2 s-1 to 8 mmol of photons m-2 s-1. Similar considerations would probably apply to photosynthetic organisms on Earth-like planets (ELPs) in the continuously habitable zone of other stars. On Earth, starlight PAR is inadequate for photosynthetically supported growth. An increase in starlight even to reach the minimum theoretical levels to allow for photosynthesis would require a universe that was approximately ten million times older, or with a ten million times greater density of stars, than is the case for the present universe. Photosynthesis on an ELP using PAR reflected from a natural satellite with the same size as our Moon, but at the Roche limit, could support a low rate of photosynthesis at full Moon. Photosynthesis on an ELP-like satellite of a Jupiter-sized planet using light reflected from the planet could be almost 1% of the rate in full sunlight on Earth when the planet was full. These potential contributions to photosynthesis require that the contribution is compared with the rate of photosynthesis driven by direct radiation from the star. Light pollution on Earth only energizes photosynthesis by organisms that are very close to the light source. However, effects of light pollution on photosynthesis can be more widespread if the photosynthetic canopy is retained for more of the year, caused by effects on photoperiodism, with implications for the influence of civilizations on photosynthesis.

Item Type: Journal Article
Copyright Holders: 2006 Mary Ann Liebert, Inc.
ISSN: 1557-8070
Academic Unit/Department: Science > Physical Sciences
Interdisciplinary Research Centre: Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)
Item ID: 7903
Depositing User: Kyra Proctor
Date Deposited: 06 Jun 2007
Last Modified: 02 Jul 2014 15:00
URI: http://oro.open.ac.uk/id/eprint/7903
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