Editing Tocantins (section)

=== Vegetation ===
[[File:FlavioAndre_PedraFurada_PonteAltadoTocantins_TO.jpg|thumb|Serra Geral do Tocantins Ecological Station]]
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The "cerrado" landscape cover 87% of Tocantins and is characterized by extensive savanna formations crossed by gallery forests and stream valleys.<ref name="t"/> Cerrado includes various types of vegetation. Humid fields and "buriti" palm paths are found where the water table is near the surface. Alpine pastures occur at higher altitudes and mesophytic forests on more fertile soils. In the north of Tocantins the cerrado gives place to a zone of transition for the [[Amazon biome]], near [[Tocantins River]].

The savanna formations are not homogenous. There is great variation between the amount of woody and herbaceous vegetation, forming a gradient from completely open "cerrado" — open fields dominated by grasses — to the closed, forest-like "cerrado" and the "[[cerradão]]" ("big cerrado"), a closed canopy forest. Intermediate forms include the dirty field, the "cerrado" field, and the "cerrado" sensu stricto, according to a growing density of trees.

The "cerrado" trees have characteristic twisted trunks covered by a thick bark, and leaves that are usually broad and rigid. Many herbaceous plants have extensive roots to store water and nutrients. The plant's thick bark and roots serve as adaptations for the periodic fires which sweep the cerrado landscape. The adaptations protect the plants from destruction and make them capable of sprouting again after the fire.

As in many savannas in the world, the "cerrado" ecosystems have been coexisting with fire since ancient times. Initially they developed adaptations to natural fires caused by lightning or volcanic activity.

Along the western boundary of the state is the floodplain of the [[Araguaia River]], which includes extensive wetlands and Amazon tropical forest ecosystems. Bananal Island, formed by two branches of the Araguaia, is said to be the largest river island in the world.<ref name="brit-b"/><ref name=brit/> It consists mostly of marshlands and seasonally flooded savannas, with gallery forest.  Where the two branches meet again they form an inland delta called [[Cantão]], a typical Amazonian [[igapó]] flooded forest.  The Araguaia is also one of the main links between the Amazonian lowlands and the [[Pantanal]] wetlands to the south, but the river is not fully navigable.