Tropical and subtropical grasslands, savannas, and shrublands

From Free net encyclopedia

Tropical and subtropical grasslands, savannas, and shrublands are a grassland biome located in semi-arid to semi-humid climate regions of subtropical and tropical latitudes. 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 50 and 150 centimetres (20 to 60 inches) a year, and can be highly seasonal, with the entire year's rainfall sometimes occurring within a couple of weeks. Much of the plant life on savannas is adapted to seasonal aridity. Adaptations to the dry climate include herbaceous annuals, which die in the dry season and re-grow from seed each year, and perennial plants which grow long tap roots to reach groundwater, or bulbs to store water.

Tropical and subtropical grasslands, savannas, and shrublands occur on all continents but Antarctica. They are widespread on Africa, and are also found in India, 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 50 and 150 centimetres of rain per year. Flora includes:

Acacia (Tree)
- Loses leaves in dry season to conserve moisture
- Leafy canopy in rainy season (flattened by winds)
Baobab (Tree)
- Stores water in trunk
- Thick bark to protect it from fires in dry season
- Long Tap roots to reach underground moisture
- Few leaves to reduce water loss through transpiration
Grass
- Grow Quickly to 3 or 4 meters in clumps
- Shoots die in dry season leaving only roots
Low Shrubs
- Drought resistant
- Small
- Thorns not leaves