Forest fragmentation in the Brazilian Amazon: Trends and conservation strategies

• Amazon forest fragmentation shows an increase in fragments and reduction in size in three decades. • The Amazon's fragmentation trajectory shifts from Core to Connector to Background. • Central Amazon demands target conservation to avoid fragmentation like Eastern Amazon. • Secondary forest may be used to reverse fragmentation. • Fragmentation metrics and trajectory nourish conservation actions. Tropical forests have experienced increasing fragmentation. The trajectory of forest fragmentation (sequence, permanence, and location) offers valuable insights for shaping environmental strategies. We examined fragmentation trends and metrics in the Brazilian Amazon over a 34-year period, encompassing its macroregions: Western (WA), Central (CA), and Eastern Amazon (EA). The findings reveal an ongoing fragmentation, characterized by an increase in fragment numbers (WA: +37%, from 49,871 to 68,067 fragments; CA: +82%, 72,463–132,051 fragments; EA: +178%, 164,249–456,399 fragments) and a reduction in mean fragment size (WA: −28%, from 2825.7–2036.8 ha; CA: −48%, 1747.4–905.4 ha; EA: −75%, 651.8–162.3 ha), particularly in the east. Transitions occurred across few forest classes, typically, from forest Core to connecting forest, and eventually to anthropogenic areas. The Core class's permanence was longest in WA (32 years), while anthropogenic areas had the highest permanence in EA (7.6 years) and the lowest in WA (<1 year). Intermediate fragmentation classes were more prevalent in EA, which also demonstrated higher entropy. CA requires immediate attention actions from decision-makers to prevent the intense fragmentation shown in EA. We suggested strategies to mitigate Amazon fragmentation, emphasizing integrated metrics and region-specific approaches for enhanced connectivity and reduced forest loss.