Hobbies And Interests
Climate
Savannas are warm all year round. There are two seasons, the dry season and the wet season, also called the rainy season or the monsoon. Most savannas get an average yearly rainfall of 30 to 40 inches, most of which is concentrated during the rainy season. If the same amount of rainfall were distributed evenly throughout the year, the same area might support a forest ecosystem instead.
Vegetation
By definition, a savanna is an open grassland with isolated trees and thorny shrubs. Savanna plants often have adaptations for getting and keeping water during the dry season, such as long tap roots that reach groundwater, or long thorns to prevent predation by animals.
Seasons
The rainy season generally starts in May. It usually ends around October, during which violent thunderstorms occur, followed by strong, dry winds. The dry season peaks around January. Some rain may occur during the dry season, totaling perhaps 4 inches over the entire season, but there can also be months without any rain at all. Savanna animals are usually adapted to surviving long periods without water, but even the most resilient species need to drink. At the height of the dry season, animals travel many miles to congregate around watering holes. Sometimes harsh droughts cause even reliable watering holes to go dry, but many are fed by springs or groundwater and retain moisture all year long.
Fire
Natural fires are an important part of the savanna ecosystem. They are most common in January, at the height of the dry season, and play an important role in keeping the land clear and maintaining the grassland. Grasses and shrubs burn and leave behind ash which serves as a rich fertilizer in the coming season, but most trees are adapted to survive the fires. The roots of most grasses also survive the fire. When the rainy season begins, the vegetation quickly recovers what was lost during the fire.
Types of Savanna
There are three basic types of savanna. The first and most common, climatic savannas, exist due to climate conditions -- usually hot weather with uneven rainfall that prevents the growth of forests and leads to wildfires. Edaphic savannas are those that are caused by soil conditions and aren't dependent on fires. These are usually located in areas where the topsoil is too shallow to support a larger plant community, or where clay soils become waterlogged after rainfall. Lastly are derived savannas, which are created when humans deforest an area through logging or burning, usually for the purpose of farming. Once the farm is abandoned because the land can no longer support crops, grasses take over and are maintained by a fire cycle similar to that of a natural savanna.