Tropical savanna climate

Tropical savanna climate or tropical wet and dry climate is a type of climate that corresponds to the categories "Aw" and "As". Tropical savanna climates have monthly mean temperatures above 18 °C (64 °F) in every month of the year and typically a pronounced dry season, with the driest month having precipitation less than 60 mm and also less than (100 – [total annual precipitation {mm}/25]). This latter fact is in direct contrast to a tropical monsoon climate, whose driest month sees less than 60 mm of precipitation but has more than (100 – [total annual precipitation {mm}/25]). In essence, a tropical savanna climate tends to either see less rainfall than a tropical monsoon climate or have more pronounced dry seasons.

There are generally four types of tropical savanna climate:

Tropical and subtropical grasslands, savannas, and shrublands

Tropical and subtropical grasslands, savannas, and shrublands are grassland terrestrial biomes located in semi-arid to semi-humid climate regions of subtropical and tropical latitudes.

Description

Grasslands are dominated by grass and other herbaceous plants. Savannas are grasslands with scattered trees. Shrublands are dominated by woody or herbaceous shrubs.

Rainfall in tropical and subtropical grasslands, savannas, and shrublands is between 500 and 1300 millimeters (20 to 50 inches) a year, and can be highly seasonal, with the entire year's rainfall sometimes occurring within a couple of weeks.

Occurrence

Tropical and subtropical grasslands, savannas, and shrublands occur on all continents but Antarctica. They are widespread in Africa, and are also found all throughout South Asia, the northern parts of South America and Australia, and the southern United States.

African Savannas occur between forest or woodland regions and grassland regions. The climate varies, with an average temperature of 27 °C with peaks of 30 °C in April and October, and between 300 and 1500 millimetres of rain per year. Flora includes:

Savanna

A savanna or savannah is a grassland ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses.

Savannas maintain an open canopy despite a high tree density. It is often believed that savannas feature widely spaced, scattered trees. However, in many savannas, tree densities are higher and trees are more regularly spaced than in forests. The South American savanna types cerrado sensu stricto and cerrado dense typically have densities of trees similar to or higher than that found in South American tropical forests, with savanna ranging 800–3300 trees/ha and adjacent forests with 800–2000 trees/ha. Similarly Guinean savanna has 129 trees/ha, compared to 103 for riparian forest, while Eastern Australian sclerophyll forests have average tree densities of approximately 100 per hectare, comparable to savannas in the same region.