Change search
ReferencesLink to record
Permanent link

Direct link
Disentangling denitrification and its environmental drivers in northern boreal lakes
Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
2015 (English)Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
Abstract [en]

Dinitrous oxide (N2O) is a potent greenhouse gas some 354 times stronger than carbon dioxide (CO2) in the atmosphere. Recent studies show that lake denitrification contributes to a considerable part of the global N2O emissions. Despite this, lake-N2O emissions are not being accounted for in global greenhouse gas modeling because it has not yet been accurately understood and quantified. The aim of this study was to assess how denitrification varies between and within boreal lakes and how it is controlled by nitrate- (NO3) and carbon (C) availability and temperature. Studies on denitrification were performed using the acetylene inhibition technique on sediments from three lakes in northern Sweden (February to August, 2014). Results showed that denitrification was correlated (linear regression, r2=0.71) with NO3 concentrations in the hypolimnion water at ambient conditions and that additions of NO3 up to a concentration of 50 µg NO3-N L-1 increased denitrification. Temperature increased denitrification in all lakes, at all sites except in one lake in July, when nutrient concentrations were at its lowest. The spatial and temporal variation in denitrification was small at ambient conditions (1-3 µmol N2O m-2 h-1)but the variation in the response to nutrient additions and temperature increase was very high. This was in part attributed to differences in dissolved organic C (DOC). These findings have important implications for future denitrification research and how lake-N2O production is included in greenhouse gas modeling and contributes to our knowledge on how northern boreal lakes may respond to enhanced nutrient loadings and global warming.

Place, publisher, year, edition, pages
Keyword [en]
Denitrification, N2O production, acetylene inhibition technique, boreal lakes
National Category
Natural Sciences Earth and Related Environmental Sciences
URN: urn:nbn:se:umu:diva-98117OAI: diva2:781809
Subject / course
Examensarbete i Geovetenskap/naturgeografi avseende masterexamen
Educational program
Master's Programme in Geoecology
Available from: 2015-01-22 Created: 2015-01-19 Last updated: 2015-01-22Bibliographically approved

Open Access in DiVA

Masterexamen, Maria Myrstener(1398 kB)106 downloads
File information
File name FULLTEXT01.pdfFile size 1398 kBChecksum SHA-512
Type fulltextMimetype application/pdf

By organisation
Department of Ecology and Environmental Sciences
Natural SciencesEarth and Related Environmental Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 106 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 4526 hits
ReferencesLink to record
Permanent link

Direct link