In this lesson we are going to discuss the grassland vegetation, the types and their characteristics
Grasslands-Found in climatic regions where a seasonal pattern occurs with a prolonged drought of about 5-7 months.Tropical Grasslands/ Savanna- Found in areas experiencing tropical continental climate.Areas1. N and S of Congo Basin.2. Between Sahel and equatorial forests in E. Africa plateau.3. N.E of Australian Desert.4. Brazilian highlandsIt’s divided into:(a) Open grasslands where grass is dominant and (b) Woodlands in areas which receive more rainfall.Characteristics• Grasslands with widely spaced trees such as acacias.• Grasses die in dry season and sprout quickly when it rains.• Grasses are tall (up to 3m with stiff blades and elephant grass is tallest reaching up to 4m.• Trees are of medium size up to 13m• Tree crowns are umbrella shaped to provide shade around roots to reduce evaporation.• Most trees are deciduous and shed leaves during dry season.• Trees have small leaves and thick barks to reduce transpiration.• Trees have long tap roots to reach the water deep below during long dry spells.Uses(a) Grass is for grazing and commercial ranching though it’s of low nutritional value due to lack of phosphorous.(b) Cereals e.g. wheat farming because the soil is rich in humus resulting from the grass cover.(c) Vegetation acts as soil cover to reduce soil erosion.(d) Homes of wild animals which attract tourists e.g. E. and C. African savannas.(e) Trees are habitats for bees which provide honey.(f) Some shrubs and herbs are used for medicine.(g) Trees such as acacia provide fuel wood and charcoal.Temperate Grasslands- Found in continental interiors of temperate grasslands where rainfall isn’t sufficient to sustain forests.LocationThe PrairiesAreas- Canadian provinces of Alberta, Saskatchewan, Manitoba and neighboring states of U.S.A.Characteristics-Continuous tuft grass-Grasses are nutritious.-Grass is short-Grass is interspersed with bulbons and leguminous plants.-Grass is mixed in some areas with species such as stipa, buffalo and gamma grasses.-Tall grasses in areas with rainfall of over 500mm.The Steppes- Found in Eurasia- temperate interiors of Europe and Asia.CharacteristicsTrue Steppes-rich carpet of grass and some flowering plants.Desert steppes - Coarse grass growing in tufts-Grass doesn’t form a continuous cover on the ground.-Short grass which grows very close to the ground.The Pampas- Found in Argentina.CharacteristicsFeather - like grass Grass forms individual tussocks with patches of bare soil.-Forests are present in some areas due to increased moisture.-Xerophytic or drought resistant plants are present in some areas.The Veldt- Found in S. Africa.Characteristics• Grasses are extensively spread.• There is little or no mixture of trees or shrubs.• There is a uniform cover of grass on high plateaus.The Downs- Found in Australia and New Zealand.Characteristics• Tall grass mixed with trees. • Semi desert areas have patches of dominant grass.• Mixture of temperate and tropical grass species.• Grass is nutritious and nutritious for livestock.• Natural grasses of Argentina have been replaced by Alfalfa and in New Zealand Britishmeadow grasses now dominate. Uses of Temperate Grasslands(a) For grain cultivation e.g. wheat which requires as low as 325mm of rainfall.(b) For cultivation of other crops e.g. oil seeds, Soya beans, vegetables and millet and sorghum widely grown inthe Veldt.(c) For livestock farming e.g. cattle, sheep, goats and horses.There are scientifically managed ranches called Estancias in Argentina.