uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Can nitrogen gas be deficient for nitrogen fixation in lakes?
Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
2007 (English)In: Ecological Modelling, ISSN 0304-3800, E-ISSN 1872-7026, Vol. 202, no 3-4, 362-372 p.Article in journal (Refereed) Published
Abstract [en]

Severe nitrogen gas (N2) depletion in lakes may have implications for N2 fixation and for model structures describing the nitrogen (N) cycle. To determine whether this is likely to occur, we first reviewed the general processes influencing the N2 cycle in lakes. Second, we empirically analysed N2 concentrations in various stations and depths of Lake Erken, Sweden during the beginning and the end of the summer stratification period of 2004. Overall, no significant deviations from N2 saturation from any stations or depths were observed during the study period. Third, we developed a simple, one-box gas model to investigate possible effects on lake water from processes described in the literature that affect the N2 concentration. Simulations indicated that bottom waters and other isolated water bodies may show strong deviations from N2 saturation during certain conditions differing from those during summers in Lake Erken. Simulated surface waters were always N2 saturated in all types of lakes where the water column was in direct contact with the air. We quantified all probable fluxes, showed that the N2 concentration in surface waters vastly exceeds the half-saturation constant for N uptake by phytoplankton, and concluded that it is unlikely that N2 fixation is ever limited by the N2 concentration. Modellers of lake eutrophication may regard N2 as being available in excess.

Place, publisher, year, edition, pages
2007. Vol. 202, no 3-4, 362-372 p.
Keyword [en]
Nitrogen gas, Lakes, Denitrification, Nitrogen fixation, Methane, Seepage, Half-saturation, Nutrient modelling
National Category
Biological Sciences
Identifiers
URN: urn:nbn:se:uu:diva-96948DOI: 10.1016/j.ecolmodel.2006.10.025ISI: 000245517000010OAI: oai:DiVA.org:uu-96948DiVA: diva2:171693
Available from: 2008-03-13 Created: 2008-03-13 Last updated: 2017-12-14Bibliographically approved
In thesis
1. Quantitative Understanding and Prediction of Lake Eutrophication
Open this publication in new window or tab >>Quantitative Understanding and Prediction of Lake Eutrophication
2008 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Many lakes around the world have been exposed to increased nutrient input from anthropogenic sources such as sewage discharge and runoff from fertilised agricultural areas. This has led to eutrophication, manifested as intensified algal blooms, murky waters, oxygen depleted lake bottoms, and alterations of considerable parts of the foodweb. However, many of these lakes have also recovered, due to improved nutrient abatement techniques and to an improved quantitative scientific understanding of eutrophication and its causes. General, predictive models have played a crucial role in the latter development, as they have made it possible to quantitatively assess expected ecosystem changes from various planned actions against eutrophication.

The present thesis has been aimed at improving the domain of validity and predictive power of a general, dynamic total phosphorus (TP) model (LakeMab) and to provide the basis for constructing a similar model for total nitrogen (TN). Among the findings in the thesis is that dissolved nitrogen gas is probably always available in excess for nitrogen fixation and nitrogen modelling in eutrophication contexts. Two papers have laid the ground for improved nutrient modelling in calcareous lakes, where sedimentation is particularly pronounced. Static models for predicting concentrations of particulate phosphorus, nitrogen, and organic carbon have been presented that may be incorporated into sedimentation algorithms in dynamic nutrient models. Boundary conditions for various flux algorithms have made it possible to greatly expand the domain of LakeMab for TP. The typical uncertainty of TP concentration values is 17% when predicted with LakeMab, whereas the uncertainty in predictions using older, static models is about twice as high.

LakeMab may be very useful for resolving practical issues such as predicting climate-induced eutrophication and drawing up operational guidelines for achieving good water quality as prescribed by, e.g., the European Water Framework Directive.

Place, publisher, year, edition, pages
Uppsala: Universitetsbiblioteket, 2008. 38 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 415
National Category
Ecology
Identifiers
urn:nbn:se:uu:diva-8593 (URN)978-91-554-7143-9 (ISBN)
Public defence
2008-04-18, Hambergssalen, Institutionen för geovetenskaper, Villavägen 16, Uppsala, 10:00 (English)
Opponent
Supervisors
Available from: 2008-03-13 Created: 2008-03-13 Last updated: 2009-03-30Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text
By organisation
Department of Earth Sciences
In the same journal
Ecological Modelling
Biological Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 530 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf