Reference levels have to eventually have national coverage, but they may be composed from a number of sub-national reference levels. As an example, forest degradation may have a reference emission level for commercial selective logging and one for extraction of minor timber and firewood for subsistence use by rural communities. Effectively, every identified driver of deforestation or forest degradation has to be represented in one or more reference emission level(s). Similarly for reference levels for enhancement of carbon stocks, there may be a reference level for plantation timber species and one for natural regeneration, possibly stratified by ecological region or forest type.
