- 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
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.