The vegetation is dense Amazon rainforest within the Centro de Endemismos Belém ecoregion, and is rich in species of flora.

Specifically the reserve maintains a representative sample of the Amazon rainforest in Maranhão.

[3] The proposed South Amazon Ecological Corridor would link the reserve to other protected areas and indigenous territories in the region.

[4] Studies with plants, butterflies and birds classify this biological reserve as one of the 12 pleistocenic refuges in the Brazilian Amazon rainforest.

[5] Protected species are Kaapori capuchin (Cebus kaapori), oncilla (Leopardus tigrinus), ocelot (Leopardus pardalis), jaguar (Panthera onca), Belem curassow (Crax pinima), Amazonian barred woodcreeper (Dendrocolaptes certhia), black-spotted bare-eye (Phlegopsis nigromaculata), red-necked aracari (Pteroglossus bitorquatus), dark-winged trumpeter (Psophia viridis) and pearly parakeet (Pyrrhura lepida).