Metcalfe, Daniel
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
Research article2013Peer reviewedOpen access
Effects of nitrogen fertilization on the forest floor carbon balance over the growing season in a boreal pine forest
Metcalfe, Daniel; Eisele, B.; Hasselquist, Niles
Abstract
Boreal forests play a key role in the global carbon cycle and are facing rapid shifts in nitrogen availability with poorly understood consequences for ecosystem function and global climate change. We quantified the effects of increasing nitrogen availability on carbon fluxes from a relatively understudied component of these forests - the forest floor - at three intervals over the summer growing period in a northern Swedish Scots pine stand. Nitrogen addition altered both the uptake and release of carbon dioxide from the forest floor, but the magnitude and direction of this effect depended on the time during the growing season and the amount of nitrogen added. Specifically, nitrogen addition stimulated net forest floor carbon uptake only in the late growing season. We find evidence for species-specific control of forest floor carbon sink strength, as photosynthesis per unit ground area was positively correlated only with the abundance of the vascular plant Vaccinium myrtillus and no others. Comparison of understorey vegetation photosynthesis and respiration from the study site indicates that understorey vegetation photosynthate was mainly supplying respiratory demands for much of the year. Only in the late season with nitrogen addition did understorey vegetation appear to experience a large surplus of carbon in excess of respiratory requirements. Further work, simultaneously comparing all major biomass and respiratory carbon fluxes in forest floor and tree vegetation, is required to resolve the likely impacts of environmental changes on whole-ecosystem carbon sequestration in boreal forests.
Published in
Biogeosciences
2013, volume: 10, number: 12, pages: 8223-8231
Publisher: COPERNICUS GESELLSCHAFT MBH
SLU Authors
Hasselquist, Niles
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
Global goals (SDG)
UKÄ Subject classification
Forest Science
Publication identifier
- DOI: https://doi.org/10.5194/bg-10-8223-2013
Permanent link to this page (URI)
https://res.slu.se/id/publ/52012