You are here: Home
/ Publication Information
Title: Competitive status influences tree-growth responses to elevated CO2 and 03 in aggrading aspen stands
Author: McDonald, E. P.; Kruger, E. L.; Riemenschneider, D. E.; Isebrands, J. G.
Source: Functional Ecology 16:792-801
Publication Series: Scientific Journal (JRNL)
Description: 1. Competition effects on growth of individual trees were examined for 4 years in aggrading, mixed-clone stands of trembling aspen (Populus tremuloides Michx.) at the Aspen-FACE free-air Co2 and O3 enrichment facility in northern Wisconsin, USA. During each growing season stands received one of four combinations of atmospheric [CO2] (ambient vs~56 Pa) and [O3] (ambient vs~1.5 x ambient). 2. Non-destructive measurements of annual tree growth were compared within and among clones and treatments in relation to an index of competitive status based on the difference between a tree's height and that of its four nearest neighbours. Competitive status strongly influenced tree growth, and the positive growth response to elevated [CO2] was greater for competitively advantaged individuals than for disadvantaged individuals of most clones. 3. The magnitude of O3 effects on growth depended on clone and competitive status: for some clones, negative O3 effects were stronger with competitive advantage while others showed stronger O3 effects with competitive disadvantage. The interactive effects of CO2 and O3 differed among clones, with negative effects of O3 amplified or ameliorated by elevated CO2, depending on clone and competitive status. 4. Treatments modified competitive interactions by affecting the magnitude of growth differences among clones. These modifications did not alter clone rankings of competitive performance, but when CO2 and 03 were both elevated, the differences in competitive performance among clones decreased.
Keywords: Competitive interactions, FACE, global change, Populus tremuloides
- 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.
- This publication may be available in hard copy. 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, email@example.com if you notice any errors which make this publication unusable.
XML: View XML
McDonald, E. P.; Kruger, E. L.; Riemenschneider, D. E.; Isebrands, J. G. 2002. Competitive status influences tree-growth responses to elevated CO2 and 03 in aggrading aspen stands. Functional Ecology 16:792-801
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility