Environmental regulation of nitrogen fixation in a high arctic lowland ecosystem
This study examined spatial and temporal variation in cyanobacterial nitrogen fixation and the environmental regulation of this variation at Truelove Lowland, Devon Island, N.W.T. Acetylene reduction rates of soil–plant cores from a variety of plant communities were measured under uniform conditions...
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Canadian Science Publishing
1991
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crcansciencepubl:10.1139/b91-345 2024-09-15T18:03:39+00:00 Environmental regulation of nitrogen fixation in a high arctic lowland ecosystem Chapin, David M. Bliss, L. C. Bledsoe, L. J. 1991 http://dx.doi.org/10.1139/b91-345 http://www.nrcresearchpress.com/doi/pdf/10.1139/b91-345 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Botany volume 69, issue 12, page 2744-2755 ISSN 0008-4026 journal-article 1991 crcansciencepubl https://doi.org/10.1139/b91-345 2024-08-29T04:08:48Z This study examined spatial and temporal variation in cyanobacterial nitrogen fixation and the environmental regulation of this variation at Truelove Lowland, Devon Island, N.W.T. Acetylene reduction rates of soil–plant cores from a variety of plant communities were measured under uniform conditions of light and temperature during the 1987 and 1988 growing seasons. Concurrent measurements of soil moisture and extractable nitrogen and phosphorus were also made. Effects of temperature, moisture, and phosphorus were examined in manipulative experiments. Acetylene reduction rates were highest in brackish environments, intermediate in mesic to hydric terrestrial and in aquatic communities, and lowest on xeric beach ridges. Rates generally increased during early season, then decreased through mid to late season. Among the three parameters examined, rates were most highly correlated to soil moisture. The temperature optimum for fixation was near 20 °C. There was a strong, but reversable, depression in acetylene reduction in response to experimental desiccation, and weekly phosphorus fertilization had a strong positive effect on fixation rates. The highest fixation rates along the marine shoreline were associated with high phosphorus input from marine algae and greater biomass of cyanobacteria. Because of the overriding importance of moisture, changes in nitrogen and phosphorus levels accompanying ecosystem development do not appear to strongly control nitrogen fixation in terrestrial, nonbrackish sites in this polar desert oasis. Key words: nitrogen fixation, environmental regulation, Devon Island, High Arctic, Nostoc commune, cyanobacteria. Article in Journal/Newspaper Devon Island polar desert Canadian Science Publishing Canadian Journal of Botany 69 12 2744 2755 |
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description |
This study examined spatial and temporal variation in cyanobacterial nitrogen fixation and the environmental regulation of this variation at Truelove Lowland, Devon Island, N.W.T. Acetylene reduction rates of soil–plant cores from a variety of plant communities were measured under uniform conditions of light and temperature during the 1987 and 1988 growing seasons. Concurrent measurements of soil moisture and extractable nitrogen and phosphorus were also made. Effects of temperature, moisture, and phosphorus were examined in manipulative experiments. Acetylene reduction rates were highest in brackish environments, intermediate in mesic to hydric terrestrial and in aquatic communities, and lowest on xeric beach ridges. Rates generally increased during early season, then decreased through mid to late season. Among the three parameters examined, rates were most highly correlated to soil moisture. The temperature optimum for fixation was near 20 °C. There was a strong, but reversable, depression in acetylene reduction in response to experimental desiccation, and weekly phosphorus fertilization had a strong positive effect on fixation rates. The highest fixation rates along the marine shoreline were associated with high phosphorus input from marine algae and greater biomass of cyanobacteria. Because of the overriding importance of moisture, changes in nitrogen and phosphorus levels accompanying ecosystem development do not appear to strongly control nitrogen fixation in terrestrial, nonbrackish sites in this polar desert oasis. Key words: nitrogen fixation, environmental regulation, Devon Island, High Arctic, Nostoc commune, cyanobacteria. |
format |
Article in Journal/Newspaper |
author |
Chapin, David M. Bliss, L. C. Bledsoe, L. J. |
spellingShingle |
Chapin, David M. Bliss, L. C. Bledsoe, L. J. Environmental regulation of nitrogen fixation in a high arctic lowland ecosystem |
author_facet |
Chapin, David M. Bliss, L. C. Bledsoe, L. J. |
author_sort |
Chapin, David M. |
title |
Environmental regulation of nitrogen fixation in a high arctic lowland ecosystem |
title_short |
Environmental regulation of nitrogen fixation in a high arctic lowland ecosystem |
title_full |
Environmental regulation of nitrogen fixation in a high arctic lowland ecosystem |
title_fullStr |
Environmental regulation of nitrogen fixation in a high arctic lowland ecosystem |
title_full_unstemmed |
Environmental regulation of nitrogen fixation in a high arctic lowland ecosystem |
title_sort |
environmental regulation of nitrogen fixation in a high arctic lowland ecosystem |
publisher |
Canadian Science Publishing |
publishDate |
1991 |
url |
http://dx.doi.org/10.1139/b91-345 http://www.nrcresearchpress.com/doi/pdf/10.1139/b91-345 |
genre |
Devon Island polar desert |
genre_facet |
Devon Island polar desert |
op_source |
Canadian Journal of Botany volume 69, issue 12, page 2744-2755 ISSN 0008-4026 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/b91-345 |
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Canadian Journal of Botany |
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69 |
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12 |
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2744 |
op_container_end_page |
2755 |
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1810441127298334720 |