The area, which has experienced increased vegetation growth 1982 to 2004 in the Senegal, Mauritania, Burkan Faso, Mali and Niger, equals 1.6 million km2, of which 1.0 million km2 has seen no increase in Rain Use Efficiency. If other factors than rainfall had supported the vegetation recovery, an increase in RUE would have been expected. This could point to either irreversible (or long term) negative effects of the droughts, or poor management and response to the change opportunity. Changes in vegetation types can also affect the vegetation signal, particularly changes from grasslands to woodlands, from annual to perennial species.
