Source–sink balance and carbon allocation below ground in plants exposed to ozone


  • Christian P. Andersen

    Corresponding author
    1. Western Ecology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, 200 SW 35th St, Corvallis, Oregon 97333, USA
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  • Note: The information in this article has been funded by the U.S. Environmental Protection Agency. It has been subjected to the Agency's peer and administrative review, and it has been approved for publication as an EPA document. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

Author for correspondence: Christian P. Andersen Tel: +1541 7544791 Fax: +1541 7544799 Email:



  • Summary 213

  • I. Introduction 213
  • II. Source–sink model: carbohydrate signaling 214
  • III. Effect of ozone on above-ground sources and sinks 216
  • IV. Decreased allocation below ground 218
  • V. Carbon flux to soils 220
  • VI. Soil food web 223
  • VII. Summary, conclusions and future research 223
  • Acknowledgements 223

  • References 223


The role of tropospheric ozone in altering plant growth and development has been the subject of thousands of publications over the last several decades. Still, there is limited understanding regarding the possible effects of ozone on soil processes. In this review, the effects of ozone are discussed using the flow of carbon from the atmosphere, through the plant to soils, and back to the atmosphere as a framework. A conceptual model based on carbohydrate signaling is used to illustrate physiological changes in response to ozone, and to discuss possible feedbacks that may occur. Despite past emphasis on above-ground effects, ozone has the potential to alter below-ground processes and hence ecosystem characteristics in ways that are not currently being considered.