Nitrogen fixation and photosynthesis in high arctic forms of Nostoc commune
Nostoc commune, a colonial cyanobacterium, has been suggested as an important contributor of nitrogen to terrestrial ecosystems in the Canadian High Arctic, yet little is known about the ecophysiology of this organism in arctic environments. This study focused on the physiological performance of mac...
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Canadian Science Publishing
1994
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Online Access: | http://dx.doi.org/10.1139/b94-119 http://www.nrcresearchpress.com/doi/pdf/10.1139/b94-119 |
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crcansciencepubl:10.1139/b94-119 2024-06-23T07:49:35+00:00 Nitrogen fixation and photosynthesis in high arctic forms of Nostoc commune Lennihan, R. Chapin, D. M. Dickson, L. G. 1994 http://dx.doi.org/10.1139/b94-119 http://www.nrcresearchpress.com/doi/pdf/10.1139/b94-119 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Botany volume 72, issue 7, page 940-945 ISSN 0008-4026 journal-article 1994 crcansciencepubl https://doi.org/10.1139/b94-119 2024-06-13T04:10:50Z Nostoc commune, a colonial cyanobacterium, has been suggested as an important contributor of nitrogen to terrestrial ecosystems in the Canadian High Arctic, yet little is known about the ecophysiology of this organism in arctic environments. This study focused on the physiological performance of macroscopic colonies of N. commune found on Devon Island, N.W.T. The objectives were to examine the influence of temperature, colony morphology, and seasonal phenology on nitrogen fixation rates and the effects of light and temperature on photosynthesis. Maximum rates of acetylene reduction in N. commune (2119 nmol C 2 H 4 ∙g −1 ∙h −1 ) were higher than those previously recorded for arctic N. commune but lower than values reported for temperate poulations. Depending on the time of the growing season, the temperature optimum for acetylene reduction varied from 15 °C to greater than 20 °C. Photosynthetic temperature optima did not occur below 20–25 °C (the highest temperatures measured). Light saturation of photosynthesis was reached at low levels of irradiance (100–150 μmol∙m −2 ∙s −1 PPFD). Acetylene reduction rates varied strongly with colony morphology. Thin, fragile, flattened colonies had higher rates than thicker, more resilient, flattened colonies or spherical colonies. Cold post-thaw temperatures appeared to delay the recovery of maximum nitrogen fixation rates for 2–3 weeks following the onset of the growing season. Compared with two other species of cyanobacteria present on Truelove Lowland (Gloeocapsa alpina and Gleotrichia sp.), N. commune had higher rates of nitrogen fixation. Key words: Nostoc commune, cyanobacteria, High Arctic, nitrogen fixation, photosynthesis. Article in Journal/Newspaper Arctic Devon Island Canadian Science Publishing Arctic Devon Island ENVELOPE(-88.000,-88.000,75.252,75.252) Canadian Journal of Botany 72 7 940 945 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
language |
English |
description |
Nostoc commune, a colonial cyanobacterium, has been suggested as an important contributor of nitrogen to terrestrial ecosystems in the Canadian High Arctic, yet little is known about the ecophysiology of this organism in arctic environments. This study focused on the physiological performance of macroscopic colonies of N. commune found on Devon Island, N.W.T. The objectives were to examine the influence of temperature, colony morphology, and seasonal phenology on nitrogen fixation rates and the effects of light and temperature on photosynthesis. Maximum rates of acetylene reduction in N. commune (2119 nmol C 2 H 4 ∙g −1 ∙h −1 ) were higher than those previously recorded for arctic N. commune but lower than values reported for temperate poulations. Depending on the time of the growing season, the temperature optimum for acetylene reduction varied from 15 °C to greater than 20 °C. Photosynthetic temperature optima did not occur below 20–25 °C (the highest temperatures measured). Light saturation of photosynthesis was reached at low levels of irradiance (100–150 μmol∙m −2 ∙s −1 PPFD). Acetylene reduction rates varied strongly with colony morphology. Thin, fragile, flattened colonies had higher rates than thicker, more resilient, flattened colonies or spherical colonies. Cold post-thaw temperatures appeared to delay the recovery of maximum nitrogen fixation rates for 2–3 weeks following the onset of the growing season. Compared with two other species of cyanobacteria present on Truelove Lowland (Gloeocapsa alpina and Gleotrichia sp.), N. commune had higher rates of nitrogen fixation. Key words: Nostoc commune, cyanobacteria, High Arctic, nitrogen fixation, photosynthesis. |
format |
Article in Journal/Newspaper |
author |
Lennihan, R. Chapin, D. M. Dickson, L. G. |
spellingShingle |
Lennihan, R. Chapin, D. M. Dickson, L. G. Nitrogen fixation and photosynthesis in high arctic forms of Nostoc commune |
author_facet |
Lennihan, R. Chapin, D. M. Dickson, L. G. |
author_sort |
Lennihan, R. |
title |
Nitrogen fixation and photosynthesis in high arctic forms of Nostoc commune |
title_short |
Nitrogen fixation and photosynthesis in high arctic forms of Nostoc commune |
title_full |
Nitrogen fixation and photosynthesis in high arctic forms of Nostoc commune |
title_fullStr |
Nitrogen fixation and photosynthesis in high arctic forms of Nostoc commune |
title_full_unstemmed |
Nitrogen fixation and photosynthesis in high arctic forms of Nostoc commune |
title_sort |
nitrogen fixation and photosynthesis in high arctic forms of nostoc commune |
publisher |
Canadian Science Publishing |
publishDate |
1994 |
url |
http://dx.doi.org/10.1139/b94-119 http://www.nrcresearchpress.com/doi/pdf/10.1139/b94-119 |
long_lat |
ENVELOPE(-88.000,-88.000,75.252,75.252) |
geographic |
Arctic Devon Island |
geographic_facet |
Arctic Devon Island |
genre |
Arctic Devon Island |
genre_facet |
Arctic Devon Island |
op_source |
Canadian Journal of Botany volume 72, issue 7, page 940-945 ISSN 0008-4026 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/b94-119 |
container_title |
Canadian Journal of Botany |
container_volume |
72 |
container_issue |
7 |
container_start_page |
940 |
op_container_end_page |
945 |
_version_ |
1802640065416921088 |