Last Updated:
February 28, 2007

GCRIO Program Overview

Library 
Our extensive collection of documents.

Privacy Policy

Archives of the
Global Climate Change Digest
A Guide to Information on Greenhouse Gases and Ozone Depletion
Published July 1988 through June 1999

FROM VOLUME 8, NUMBER 11, NOVEMBER 1995

PROFESSIONAL PUBLICATIONS...
IMPACTS OF ELEVATED CO₂

Item #d95nov51

"Towards a Better Experimental Basis for Upscaling Plant Responses to Elevated CO₂ and Climate Warming," Ch. Körner (Inst. Botany, Univ. Basel, CH-4056 Basel, Switz.), Plant, Cell & Environ., 18(10), 1101-1110, Oct. 1995.

Few of the most common assumptions used in modeling plant and ecosystem responses to elevated CO₂ and temperatures have been tested under realistic life conditions. Identifies unexpected discrepancies between predictions and experimental findings, which indicate that a better empirical basis is required for predictions. Offers ten suggestions for improving our ability to scale up from experimental conditions to the real world.

Item #d95nov52

"Stomatal Responses to Increased CO₂: Implications from the Plant to the Global Scale," C.B. Field (Carnegie Inst. of Washington, Stanford CA 94305), R.B. Jackson, H.A. Mooney, ibid., 1214-1225.

There are few studies of ecosystem effects of elevated CO₂ mediated through decreased leaf conductance of moisture. This discussion is based on theory, experiments in which other variables provide surrogates for CO₂ effects, and a "healthy dose of speculation." Concludes that, because certain negative feedbacks depend on the aerodynamic roughness of the terrain, effects of elevated CO₂ on conductance are unlikely to have large effects on the hydrological cycle in productive (aerodynamically smooth) agricultural regions, but will be most important in natural forests, shrublands and dry grasslands. Decreased canopy conductances over large regions may lead to increased temperature and decreased precipitation, and these climatic effects could be important regionally, especially in combination with greenhouse warming.

Item #d95nov53

"Elevated Concentrations of CO₂ May Double Methane Emissions from Mires," P.R. Hutchin, M.C. Press (Dept. Animal & Plant Sci., Univ. Sheffield, POB 601, Sheffield, UK) et al., Global Change Biology, 1(2), 125-128, Apr. 1995.

Intact cores of peat and vegetation were removed from a mire and buried in open top chambers, where they were exposed to a 60% increase in CO₂. A profound increase in methane emissions was observed over the four-month period of study, accompanied by a 100% increase in the rate of photosynthesis.

Item #d95nov54

"Effects of Elevated CO₂ and/or O3 on Growth, Development and Physiology of Wheat (Triticum aestivum L.)," J.D. Barnes (Dept. Agric. Sci., Univ. of Newcastle-upon-Tyne, Newcastle-upon-Tyne NE1 7RU, UK), J.H. Ollerenshaw, C.P. Whitfield, ibid., 129-142.

Plants exposed to both ozone and CO₂ in a test chamber showed enhanced growth due to elevated CO₂, but little evidence that CO₂ enrichment afforded extra protection against O3 damage. On the contrary, CO₂ enrichment may render plants more susceptible to O3 damage at the cellular level.

Item #d95nov55

"Elevated Carbon Dioxide Affects Leaf-Miner Performance and Plant Growth in Docks (Rumex spp.)," D.T. Salt (Biolog. Sciences, Lancaster Univ., Lancaster LA1 4YQ, UK), G.L. Brooks, J.B. Whittaker, ibid., 153-156.

Plants exposed to elevated CO₂ showed greater leaf area and an increased C:N ratio, but leaf miners also produced larger mines in the leaves. Results are consistent with the hypothesis that herbivores compensate for increased C:N ratios by increased food consumption, an effect which could partially offset predicted increases in plant biomass in a future high-CO₂ environment.

Item #d95nov56

"Modelling the Effects of Atmospheric CO₂ on Vegetation-Atmosphere Interactions," A.D. Friend (Inst. Terr. Ecol., Bush Estate, Penicuik EH16 0QB, UK), P.M. Cox, Agric. & Forest Meteor., 73(3-4), 285-295, Mar. 1995.

Describes experiments with a combined climate-vegetation model simulating doubled CO₂ at an Amazon location. Results show that vegetation and climate responses to CO₂ concentration cannot be considered in isolation: the effects of feedback could be at least as important as any direct effects.

Item #d95nov57

"Tansley Review No. 71: Effects of Elevated Atmospheric CO₂ on Woody Plants," R. Ceulemans (Dept. Biol., Univ. Antwerpen, UIA, Universiteitsplein 1, Wilrijk B-2610, Belg.), M. Mousseau, New Phytologist, 127(3), 425-446, July 1994.

A major review of experimental methods and findings, emphasizing changes in underground processes and how they relate to the functioning of the ecosystem. Discusses directions for future research.