Write a geographical account of Tropical Grasslands under the following headings: (a) Location; (b) Climatic factors affecting the distribution; (c) Vegetat...

Answer Details

Tropical Grasslands (Savanna)

(a) Location

Tropical grasslands lie between the tropical rainforest and the hot deserts, roughly between latitudes 5 degrees and 15-20 degrees north and south of the Equator. Major areas include the savanna of West and East Africa (the Sudan and Guinea savanna, the Serengeti), the llanos of the Orinoco basin and campos of Brazil in South America, and parts of northern Australia and the Deccan of India.

(b) Climatic factors affecting distribution

• Alternating wet and dry seasons: a distinct rainy season (high sun) and a long dry season (low sun) which prevents dense forest and favours grasses.
• Moderate, seasonal rainfall of about 500-1,000 mm concentrated in the wet season.
• High temperatures all year (about 21-32 degrees C), being within the tropics.
• Movement of the ITCZ and the influence of wet maritime and dry continental (Harmattan/Trade) winds, which control the length of the seasons.

(c) Vegetation characteristics

• Dominated by tall grasses (elephant grass) that grow lush in the wet season and turn brown and dry, sometimes burning, in the dry season.
• Scattered, drought-resistant trees such as the baobab and acacia, which are deciduous, have small leaves, thick bark and flat/umbrella crowns.
• Trees are more numerous and taller near the forest margin and become fewer and shorter (giving way to thorn scrub) towards the desert margin.
• Vegetation is xerophytic (adapted to drought) with long roots and fire-resistant features.