The Purus várzea (NT0156) is an ecoregion of seasonally flooded várzea forest in the central Amazon basin. It is part of the Amazon biome.The ecoregion is home to a vegetation adapted to floods of up to 12 metres (39 ft) that may last for eight months.There is a great variety of fish and birds, but relatively fewer mammals. Ground-dwelling mammals must migrate to higher ground during the flood season.Threats include logging, cattle farming, over-fishing and mercury pollution from gold mining.