Skip to Main Content
Atmospheric CO2 and O3 alter competition for soil nitrogen in developing forestsAuthor(s): Donald R. Zak; Mark E. Kubiske; Kurt S. Pregitzer; Andrew J. Burton
Source: Global Change Biology. 18: 1480-1488.
Publication Series: Scientific Journal (JRNL)
Station: Northern Research Station
View PDF (186.94 KB)
DescriptionPlant growth responses to rising atmospheric CO2 and O3 vary among genotypes and between species, which could plausibly influence the strength of competitive interactions for soil N. Ascribable to the size-symmetric nature of belowground competition, we reasoned that differential growth responses to CO2 and O3 should shift as juvenile individuals mature, thereby altering competitive hierarchies and forest composition. In a 12-year-long forest FACE experiment, we used tracer 15N and whole-plant N content to assess belowground competitive interactions among five Populus tremuloides genotypes, between a single P. tremuloides genotype and Betula papryrifera, as well as between the same single P. tremuloides genotype and Acer saccharum. Under elevated CO2, the amount of soil N and 15N obtained by the P. tremuloides genotype common to each community was contingent on the nature of belowground competition. When this genotype competed with its congeners, it obtained equivalent amounts of soil N and tracer 15N under ambient and elevated CO2; however, its acquisition of soil N under elevated CO2 increased by a significant margin when grown in competition with B. papyrifera (+30%) and A. saccharum (+60%). In contrast, elevated O3 had no effect on soil N and 15N acquisition by the P. tremuloides genotype common in each community, regardless of competitive interactions. Under elevated CO2, the rank order of N acquisition among P. tremuloides genotypes shifted over time, indicating that growth responses to CO2 change during ontogeny; this was not the case under elevated O3. In the aspen-birch community, the competitive advantage elevated CO2 initially conveyed on birch diminished over time, whereas maple was a poor competitor for soil N in all regards. The extent to which elevated CO2 and O3 will shape the genetic structure and composition of future forests is, in part, contingent on the time-dependent effects of belowground competition on plant growth response.
- Check the Northern Research Station web site to request a printed copy of this publication.
- Our on-line publications are scanned and captured using Adobe Acrobat.
- During the capture process some typographical errors may occur.
- Please contact Sharon Hobrla, firstname.lastname@example.org if you notice any errors which make this publication unusable.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationZak, Donald R.; Kubiske, Mark E.; Pregitzer, Kurt S.; Burton, Andrew J. 2012. Atmospheric CO2 and O3 alter competition for soil nitrogen in developing forests. Global Change Biology. 18: 1480-1488.
Keywordsbelowground competition, elevated CO2, elevated O3, interspecific competition, intraspecific competition, soil N
- Scaling ozone responses of forest trees to the ecosystem level in a changing climate
- Effects of elevated concentrations of atmospheric CO2 and tropospheric O3 on leaf litter production and chemistry in trembling aspen and paper birch communities
- Effects of elevated atmospheric CO2 and/or O3 on intra- and interspecific competitive ability of aspen
XML: View XML