Oak forest habitat in Manitoba is made up of a canopy of bur oak trees with an understorey of shrubs such as hazel, hawthorn, poison ivy, snowberry and wild rose. In Manitoba, oak forest dominates on very dry sites, including gravel ridges or the upper terrace within a riverbottom forest where flooding rarely occurs. Thick stands of pure oak are not common in Manitoba. More often, bur oak trees are found mixed in with aspen trees, and most of the aspen forest habitat sites inventoried in Winnipeg also contain some oak trees. In the tall-grass prairie region of southern Manitoba, small stands of oak can be found mixed with openings of native prairie, creating a blend of plant communities sometimes referred to as "oak savannah".