Global map showing forested areas. In this map forested areas are defined as those that where at least 30 per cent of the land is covered by trees. The scale runs from beige (1 per cent forest cover), through light green (50 percent forest cover) to dark green (100 per cent forest cover). Accurate measurements of forest cover are important for calculating biomass and carbon stores. Data obtained by the Landsat 5 and 7 satellites between 2000 and 2009.