Overview

• An international team tracking 188 long-term plots across the basin reports average tree size increases of roughly 3.2–3.3% per decade, with gains evident across size classes and strongest in large trees.
• The peer-reviewed Nature Plants analysis attributes much of the growth to CO2 fertilization, challenging expectations that the biggest trees would fare worst under climate stress.
• Researchers say larger trees boost carbon storage, though they warn the growth spurt may be temporary and should not be seen as offsetting mounting climate and land-use pressures.
• Brazil’s space agency INPE reports more than 4,500 square kilometers of forest cleared in 2025, intensifying fragmentation that threatens forest connectivity, regeneration, and the survival of long-lived giants.
• The findings land just before COP30 in Belém and are expected to inform policy debates, with scientists urging protection of intact, old-growth forests that cannot be quickly replaced.