While the dictionary definition of a savanna is “a tropical or subtropical grassland containing scattered trees and drought-resistant undergrowth,” a better, more practical definition would be stated as follows:
a traditional landscape containing more than one mature tree per acre, but less than 50 per cent of canopy cover. Savannas provide a transitional but stable plant community between the prairie and the forest. Many anthropologists have called savannas the most comfortable human environment, the theory being that they have traditionally provided the best combination of shelter, fuel and potential for crop production. Indeed it is savannas that many municipal parks, home landscapes, highway medians and street boulevards most closely emulate.
Maintaining the special balance between the grasses and trees of a savanna is only possible where fire is a practical management tool. Burr oaks, which are highly fire resistant, are the predominant tree species in savanna landscapes.
Thickety shrubs such as chokecherry, Juneberry and American plum, are also common, along with a broad diversity of grasses and forbs (broadleaf, usually flowering plants). Rarer savannas are coniferous-based, featuring fire-resistant species such as jack pine and white pine.
Savanna restoration usually involves a process of thinning out areas that have been overcome by woody plants, usually because of the absence of large grazing animals like bison and elk, as well as the absence of fire. Restoration of ground layer species is also usually necessary and must include special attention to species selection - some are highly specific to savanna conditions. Fire management is almost always recommended as a long-term strategy.