Considering predominant land use as a criterion for defining a forest will have implications for negotiations, implementation, monitoring and reporting. Applying the forest definition of the MA could considerably increase the total forest area affected by an agreement. Appendix 2 lists agroforestry systems ranging from quasi closed forests to croplands with sparse trees, covering about 400 Mha worldwide12. The difficulties of monitoring such very diverse areas and estimating carbon losses within a certain confidence interval would increase over-proportionally with the areas included.
Related terms and definitions are found in the glossary (Annex I): tree, shrub, primary forest, modified natural forest, semi-natural forest, managed forest, planted forest, forest plantation, agro-forestry, other wooded land, other land, other land with tree cover, open forest, closed forest, fallow systems, fragmented forest, urban forest.
♦ Existing national definitions of forest in developing countries are rarely directly applicable;
♦ To avoid proliferating definitions, incompatibilities, inconsistencies and complications in implementation, monitoring and reporting, a single definition of forest might eventually be considered for all purposes of the climate change regime, which is meaningful in terms of greenhouse gases and satisfies the criteria listed above;
♦ Given their prevalence in developing countries and ambiguous classification as forest or non-forest, fragmented forests and forest fallow-systems (long and short fallows) must clearly be defined and explicitly in- or excluded ;
♦ Parties might consider defining additionally a minimum strip width and a maximal spatial assessment unit for deforestation and carbon stock changes within forests.
12 with an average carbon storage of 9, 21, 50,and 63 t C / ha in semiarid, sub-humid, humid and temperate regions, respectively (Montagnini and Nair, 2004).