Brazil's revisions to its Forest Code threaten not only the Amazon rainforest but also its wetlands (Nature 476, 259–260; 2011). Many Brazilian flood plains extend into neighbouring countries, so they could also be affected.

Seasonal rainfall causes the levels of most Brazilian rivers to fluctuate. Flood plains reach widths of tens of metres along small streams and tens of kilometres along large rivers, and up to 90% of these dry up during periods of low rainfall.

These wetlands provide the environment and humans with important services, such as water storage, discharge buffering, water clearing, sediment retention, recharging of the groundwater level, local and regional climate regulation, and maintenance of a large biodiversity. Some provide homes and livelihoods for traditional human populations as they harbour important fish stocks and can also be managed for low-density cattle ranching and timber production.

Neither the old nor the new version of the Forest Code specifically mentions wetlands. The old code protects forests along streams and rivers, according to the river's width and maximum water level, thereby integrating and protecting the wetland areas. The new code protects areas only to a poorly defined “regular” water level, opening up opportunities for the destruction of high-lying wetland areas. This will damage the integrity of the remaining low-lying areas, along with most of their benefits for humans and the environment.

The Intergovernmental Panel on Climate Change predicts that large parts of Brazil will experience heavier rainy seasons and more severe dry periods interspersed with heavy rainfall. Buffering by intact wetlands will be increasingly important as water availability and distribution become the limiting factors for agricultural development and the well-being of rural and urban populations.