Iriri River Terra do Meio Ecological Station. The river varies greatly in volume depending on the season, and in the dry season include waterfalls, rocks and rapids. The Iriri River flows through the Tapajós-Xingu moist forests ecoregion. The river is rich in fish, including many species found only here and in the Xingu. Large sections remain unexplored due to its remoteness in a region surrounded by Amazon rainforest, and sections with strong current and cataracts. Iriri River The Iriri River () is a large tributary of the Xingu River in Brazil, in the state of Pará. It is long making it the
Tapajós-Xingu moist forests the ecoregion blends into the Mato Grosso seasonal forests ecoregion. Elevations range from above sea level along the Amazon to in the south. The ecoregion mostly lies on the undulating terrain of the ancient Brazilian Shield. Soils are often rich in nutrients, but poor soils are found in the higher areas. The main rivers are blackwater, with little or no suspended sediment. The largest is the Iriri, a tributary of the Xingu. Others are the Jamanxim, Curuá, Crepori, Curuá Una, and Jaraucu. The ecoregion is in the neotropic ecozone and the tropical and subtropical moist broadleaf forests biome. The Köppen