Understanding Flooded Forests: Long-Term Research in the Amazon

Igapó forests, also known as blackwater flooded forests, are seasonally flooded ecosystems in the Amazon that can remain submerged for up to six months each year. These extreme conditions support highly specialized plant and animal communities and play an important role in maintaining Amazonian biodiversity and carbon storage.
Despite the Amazon being the largest tropical forest on Earth, Igapó forests remain among its least studied habitats. Deforestation, climate extremes such as El Niño, and human-induced fires are increasingly threatening these ecosystems. Fire events can cause mortality of up to 90% of trees, with ecological impacts lasting for decades and affecting both vegetation and wildlife.

This expedition aimed to improve understanding of how igapó forests respond to long-term environmental change by monitoring forest structure, biomass, and carbon stock. In parallel, researchers studied bird communities across intact and fire-affected areas to assess how biodiversity changes in response to human disturbance. Birds were identified, biological and habitat data were collected, and genetic samples were obtained for inclusion in INPA’s globally accessible genetic resource collection.