Amazonian river islands: biodiversity Hotspots, carbon Reservoirs, and ecological corridors in need of integrated conservation

Abstract

Amazonian islands represent highly dynamic and unique ecosystems shaped by sedimentation, tidal influences, and ecological succession, fostering remarkable biodiversity yet remaining increasingly threatened by human activities. Despite their ecological importance, these islands are under-researched, underscoring the need for integrated management strategies that reconcile environmental protection with local socio-economic needs. This review consolidates current knowledge on their formation, vegetation, climate, soils, and human impacts while identifying research gaps and future directions. Originating from complex sedimentary processes driven by hydrodynamics, sediment supply, and climate, these islands harbor diverse and sometimes endemic flora and fauna. Their soils are crucial for carbon storage and climate regulation, but are highly vulnerable to deforestation, land-use change, and climate variability. Human activities, including agriculture and infrastructure development, further threaten their ecological integrity. Effective conservation requires strategies aligned with sustainable development goals and community participation, promoting practices that safeguard ecosystems while supporting livelihoods. A deeper understanding of the ecological dynamics, resilience, and responses of these islands to both climate and anthropogenic pressures is essential to guide evidence-based policy, conservation planning, and sustainable management. Expanding this knowledge will help preserve ecological functions and contribute to broader environmental sustainability efforts across the Amazon basin.