The 2010 drought, which spread across 1.68 million km2 in the
southeastern part (19), resulted in 5% reduction in NDVI (5). In
both of these cases, decline in canopy greenness was limited to
a much shorter period (Fig. S4) than the changes shown in Fig.
4A. Although vegetation decline after reductions in precipitation
was evident, increase in precipitation did not necessarily result in
an increase in greenness (Fig. 4 D and E).
In addition to tropical evergreen forest, precipitation was also
reduced across about 80% of the deciduous forest (1.4 million
km2) and adjacent grassland savannah (3.3 million km2) by, on
average, about 25% and 30%, respectively (Fig. 4 B and C). Net
decrease in precipitation accounted for between 49% (deciduous
broadleaf) and 66% (grassland savanna) of the decline in vegetation
greenness. An average decline of about 4% (Fig. 4B) occurred
across drier deciduous broadleaf vegetation, whereas
NDVI in the drier grassland savannas decreased by about 7%
between 2000 and 2012 (Fig. 4C).