Please use this identifier to cite or link to this item: https://hdl.handle.net/1959.11/29427
Title: How is nitrogen fixation in the high arctic linked to greenhouse gas emissions?
Contributor(s): Stewart, Katherine J (author); Brummell, Martin E  (author)orcid ; Coxson, Darwyn S (author); Siciliano, Steven D (author)
Publication Date: 2013
Early Online Version: 2012-05-16
DOI: 10.1007/s11104-012-1282-8
Handle Link: https://hdl.handle.net/1959.11/29427
Abstract: Background and aims Approximately 50 % of belowground organic carbon is present in the northern permafrost region and due to changes in climate there are concerns that this carbon will be rapidly released to the atmosphere. The release of carbon in arctic soils is thought to be intimately linked to the N cycle through the N cycle’s influence on microbial activity. The majority of new N input into arctic systems occurs through N2-fixation; therefore, N2-fixation may be the key driver of greenhouse gases from these ecosystems.
Methods At Alexandra Fjord lowland, Ellesmere Island, Canada concurrent measurements of N2-fixation, N mineralization and nitrification rates, dissolved organic soil N (DON) and C, inorganic soil N and surface greenhouse gas fluxes (CO2, N2O and CH4) were taken in two ecosystem types (Wet Sedge Meadow and Dryas Heath) over the 2009 growing season (June-August). Using Structural Equation Modelling we evaluated the hypothesis that CO2, CH4 and N2O flux are linked to N2-fixation via the N cycle.
Results The soil N cycle was linked to CO2 flux in the Dryas Heath ecosystem via DON concentrations, but there was no link between the soil N cycle and CO2 flux in the Wet Sedge Meadow. Methane flux was also not linked to the soil N cycle, nor surface soil temperature or moisture in either ecosystem. The soil N cycle was closely linked to N2O emissions but via nitrification in the Wet Sedge Meadow and inorganic N in the Dryas Heath, indicating the important role of nitrification in net N2O flux from arctic ecosystems.
Conclusions Our results should be interpreted with caution given the high variability in both the rates of the N cycling processes and greenhouse gas flux found in both ecosystems over the growing season. However, while N2-fixation and other N cycling processes may play a more limited role in instantaneous CO2 emissions, these processes clearly play an important role in controlling N2O emissions.
Publication Type: Journal Article
Source of Publication: Plant and Soil, 362(1-2), p. 215-229
Publisher: Springer Netherlands
Place of Publication: Netherlands
ISSN: 1573-5036
0032-079X
Fields of Research (FoR) 2008: 060504 Microbial Ecology
050304 Soil Chemistry (excl. Carbon Sequestration Science)
Fields of Research (FoR) 2020: 310703 Microbial ecology
410604 Soil chemistry and soil carbon sequestration (excl. carbon sequestration science)
Socio-Economic Objective (SEO) 2008: 961499 Soils not elsewhere classified
Socio-Economic Objective (SEO) 2020: 180699 Terrestrial systems and management not elsewhere classified
Peer Reviewed: Yes
HERDC Category Description: C1 Refereed Article in a Scholarly Journal
Appears in Collections:Journal Article
School of Environmental and Rural Science

Files in This Item:
1 files
File SizeFormat 
Show full item record

SCOPUSTM   
Citations

28
checked on Aug 10, 2024

Page view(s)

1,040
checked on Aug 11, 2024

Download(s)

6
checked on Aug 11, 2024
Google Media

Google ScholarTM

Check

Altmetric


Items in Research UNE are protected by copyright, with all rights reserved, unless otherwise indicated.