Abstract. After reviewing the Kyoto Protocol rules for carbon sequestration accounting and the different carbon accounting methods proposed in the literature for forest management, for reforestation and, more recently, for avoided deforestation or degradation, we discuss possible carbon accounting rules for a post-Kyoto world. We then apply the results of this discussion to micro-applications in an Annex I country (Spain) and in a non-Annex I country (Tunisia), comparing avoided degradation with reforestation alternatives. In both areas we focus on Mediterranean forest, one of the world's hotspots of biodiversity. We calculate CO2 break-even prices, including in the analysis not only commercial values, but also, where these are relevant, existing subsidies. We also investigate social preferences for avoided degradation and reforestation using stated preference methods. Our results support the convenience of a change in focus for European Union subsidies from reforestation to avoided degradation.