The combination of natural elements--grass, small groupings of woody areas and a dry climate is common to most savannahs as they are often a transitional area between forest, desert and prairie. The largest savannah area is found in Africa. While there are several common environmental dangers for savannahs, the majority of them are a result of human interference with the natural balance of the ecosystem. Excessive interference into the savannah ecosystem can lead to desertification of the land--where vegetation growth is severely inhibited.
Savannahs suffer from the effects of wildfires, which have a tendency to occur fairly regularly. Often, these brush fires are a result of fires started by humans. Wildfires that are a result of human fire use are either ones deliberately set by aboriginal peoples to help facilitate vegetation growth or are the result of accidents. For instance, in Africa, many ethnic groups still use an open fire for cooking, and accidental brush fires can easily occur from an out of control cooking fire. Wildfires are a danger to savannahs because they have the potential to destroy much of the plant life that provides the soil with nutrients and protects from soil erosion. This makes it difficult, if not impossible, for a savannah to return to its previous levels of fertility.
Savannah areas are often cleared of trees to help with pasture production. This is particularly true for Australia, where large areas of savannah have been cleared for grazing animals to help increase the production of available feed for livestock. As well, savannahs have been cleared for ranches, plantations and large estates to develop or increase crop cultivation. Cleared savannah land has been used to produce products such as coffee, beans, rice and corn. South American culture, particularly in Brazil, has a history of using savannah areas for crop development. When a savannah is cleared of trees for crop cultivation, or is over grazed during pasture production, soil erosion becomes more commonplace. With soil erosion, nutrients in the soil leach out more readily, making the land less fertile and accommodating to plant growth. Over time, without sufficient nutrient replenishment, the land can become barren.
As climate change takes place around the world, natural resources for sustaining the savannah ecosystem becomes gradually depleted. In particular, a lack of consistent and sufficient rainfall can lead to the desertification and death of a savannah. Over time, if there is a consistent decrease in the average rainfall of a given year, a drought takes place as groundwater reserves become diminished. Gradually, plant life will die due to insufficient rain.
Savannah areas have been cleared to make way for urban development projects. This is particularly true for savannah and grassland areas in the United States, where increasing suburban developments mean that open natural spaces become a highly coveted commodity. As part of the process of urban development, deforestation is a common practice.