13.7.5 What is a grassland? Temperate and tropical grasslands, often called savannas, are dominated by an almost continuous cover of grass. They are a transitional zone between rainforests and deserts. Rainfall levels are too high to be classified as a desert, but not enough to support the tall trees and dense vegetation of a rainforest (see FIGURE8 ).
FIGURE8 Grasslands are found on every continent except Antarctica.
ARCTIC OCEAN
Arctic Circle
ATLANTIC
Tropic of Cancer
OCEAN
PACIFIC
Equator
OCEAN
INDIAN
OCEAN
Tropic of Capricorn
Key
Temperate grasslands Savannah / tropical grasslands
0
5000
10000km
Source: Based on data from Geography Teachers Associations of NSW. Map redrawn by Spatial Vision.
Grasslands have a ‘park like’ appearance, due to the absence of trees. When present, trees are scattered and often ‘flat topped’ resembling stunted shrubs. Narrow strips of trees, referred to as ‘gallery forests’, are found rivers and streams. The ecosystem is maintained by grazing animals and Indigenous communities who use fire to manage the landscape. Fire prevents tree growth and encourages the growth of grass which attracts grazing animals. Grasslands can easily be converted to desert if not managed carefully. Savanna grasslands have three main characteristics: wet summers, dry winters, and hot all year round.
• wet summer — the wet • dry winters — the dry • hot all year round.
13.7.6 The Serengeti grasslands Located in northern Tanzania and south-west Kenya the Serengeti grassland ecosystem has rich volcanic soils and the mass migration of animals has a positive ecological impact on the area. The Masai live a traditional nomadic lifestyle as cattle herders, subsisting off their herds and the land; they believe that sedentary agriculture damages the environment. Today, their lifestyle is threatened by restrictions imposed by drought; the government limits how land can be used within a national park. The tourism industry operates under strict conditions ( FIGURE9 ).
FIGURE9 The lifestyle of the Masai and the opportunity to go on a wildlife safari has resulted in a massive influx of tourists into the Serengeti.
TOPIC13 Landforms and landscapes – diversity, significance and management 317
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