A gallery forest is one formed as a corridor along rivers or wetlands, projecting into landscapes that are otherwise only sparsely treed such as savannas, grasslands, or deserts. The gallery forest maintains a more temperate microclimate above the river. Defined as long and narrow forest vegetation associated with rivers, gallery forests are structurally and floristically heterogeneous.
The habitats of these forests differ from the surrounding landscapes because they are, for example, more nutrient-rich or moister and/or there is less chance of fires. The forests are sometimes only a few meters wide, because they depend on the water they lie along.