Upturn in secondary forest clearing buffers primary forest loss in the Brazilian Amazon

Brazil contains two-thirds of remaining Amazonian rainforests and is responsible for the most Amazon forest loss. Primary forest loss in the Brazilian Amazon has declined considerably since 2004 but secondary forest loss has never been quantified. We use a recently developed high-resolution land use/land cover dataset to track secondary forests in the Brazilian Amazon over 14 yr, providing the first estimates of secondary forest loss for the region. We find that secondary forest loss increased by (187 +/- 48)% from 2008 to 2014. Moreover, the proportion of total forest loss accounted for by secondary forests rose from (37 +/- 3)% in 2000 to (72 +/- 5)% in 2014. The recent acceleration in secondary forests loss occurred across the entire region and was not driven simply by increasing secondary forest area but probably a conscious preferential shift towards clearance of a little-protected forest ecosystem (secondary forests). Our results suggest that secondary forests loss has eased deforestation pressure on primary forests. However, this has been at the expense of a lost carbon sequestration opportunity of 2.59-2.66 Pg C over our study period. Deforestation in the Brazilian Amazon affects both older (primary) and younger (secondary) forests. This study finds that most forest loss over the period 2008-2014 was from secondary forests and that the almost 190% rise in deforestation buffered losses from primary forests.