Title: Growth and crown architecture of two aspen genotypes exposed to interacting ozone and carbon dioxide
Author: Dickson, Richard E.; Coleman, M.D.; Pechter, Priit; Karnosky, David;
Source: Environmental Pollution 115 (2001) 319-334
Publication Series: Miscellaneous Publication
Description: To study the impact of ozone (O3) and O3 plus CO2 on aspen growth, we planted two trembling aspen clones, differing in sensitivity to O3, in the ground in open-top chambers and exposed them to different concentrations of O3 and O3 plus CO2 for 98 days. Ozone exposure (58 to 97 µl1-1-h, total exposure) decreased growth and modified crown architecture of both aspen clones. Ozone exposure decreased leaf, stem, branch, and root dry weight particularly in the O3 sensitive clone (clone 259). The addition of CO2 (150 µl1-1 over ambient) to the O3 exposure counteracted the negative impact of O3 only in the O3 tolerant clone (clone 216). Ozone had relatively little effect on allometric ratios such as, shoot/ root ratio, leaf weight ratio, or root weight ratio. In both clones, however, O3 decreased the shoot dry weight/shoot length ratio and shoot diameter. This decrease in wood strength caused both current terminals and long shoots to droop and increased the branch angle of termination. These results show that aspen growth is highly sensitive to O3 and that O3 can also significantly affect crown architecture. Aspen plants with drooping terminals and lateral branches would be at a competitive disadvantage in dense stands with limited light.
Keywords: Populus tremuloides, Ozone exposure, Elevated CO2, Crown architecture, Genotypic response
- 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.
- You may send email to firstname.lastname@example.org to request a hard copy of this publication. (Please specify exactly
which publication you are requesting and your mailing address.)
XML: View XML
Dickson, Richard E.; Coleman, M.D.; Pechter, Priit; Karnosky, David 2001. Growth and crown architecture of two aspen genotypes exposed to interacting ozone and carbon dioxide. Environmental Pollution 115 (2001) 319-334
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility