Grade 10 Environmental Studies: Biosphere & Biomes

• Grade 10 Environmental Studies covers:
  • Biosphere
  • Biomes
  • Environment
  • Ecosystem
  • Abiotic factors
  • Biotic factors

Terminology

• Lithosphere: The outer layer of the earth, composed of soil and rocks.
• Atmosphere: The layer of gases that surround the earth.
• Hydrosphere: The water on the surface of the earth.
• Biome: A large area characterized by a specific climate with distinct plants and animals.
• Ecosystem: A specific area where biotic (living) and abiotic (non-living) components interact.
• Ecology: The study of interactions among living organisms and between organisms and their environment.
• Hygroscopic water: A layer of water that sticks to soil particles and is difficult for plant roots to absorb.
• Capillary water: Water found between soil particles, easily absorbed by plant roots.

Biosphere

• The global sum of all ecosystems, encompassing the regions of Earth where living organisms exist.
• It consists of:
  • Atmosphere: The air layer around Earth; includes gases like nitrogen, oxygen, and carbon dioxide.
  • Lithosphere: The outer layer of Earth, made of soil and rocks.
  • Hydrosphere: All water on Earth's surface, including oceans, rivers, and lakes.

Biomes

• A specific physical environment that spans a large geographical area.
• Biomes have a particular climate, which supports a specific group of plants and animals.
• Two types of biomes:
  • Terrestrial (land-based)
  • Aquatic (water-based).
• Terrestrial biomes in South Africa:
  • Fynbos
  • Forest
  • Grasslands
  • Savannah
  • Thicket
  • Nama Karoo
  • Succulent Karoo
  • Desert
• Aquatic biomes:
  • Inland (freshwater)
  • Coastal (saltwater)
  • Marine (saltwater)

Biomes in South Africa

• The biomes are shown on a map.
• 8 different biomes are in the Southern African region.

Savannah Biome

• A vegetation type with well-developed grassy layers and an upper layer of woody plants.
• The largest biome in South Africa.
• Mainly found in Mpumalanga and Limpopo.
• Also located in the coastal belt of KwaZulu-Natal (KZN) and the Eastern Cape Province.

Grassland Biome

• It is found in parts of 6 provinces in South Africa, and 2 countries in the South African region
• Dominated by grasses.
• Two types of grasses are present;
  • Sweet grasses
  • Sour grasses
• Sweet grasses grow on fertile soil, have good food value, and are preferred by animals.
• Sour grasses grow on infertile soil, have less food value, and are avoided by animals.

Nama Karoo Biome

• Considered a semi-desert area
• This biome forms a large part of South Africa

Succulent Karoo Biome

• Found on the west coast of the Northern Cape Province, and the northern parts of the Western Cape Province.
• Dominated by dwarf shrubs.
• 40% of the species are endemic to this area.
• The Namaqualand region is world-famous for colourful wildflowers.

Fynbos Biome

• Found mainly in the Western Cape.
• Fynbos refers to dwarf shrubs with fine leaves.
• When used to describe a biome, it refers to all vegetation found in this biome, including:
  • Dwarf shrubs
  • Large shrubs
  • Trees
• Very little grass is present, but leafless tufted grass plants occur.

Forest Biome

• Found in patches spread over four provinces.

Key Concepts

• Herbaceous plants have green, fleshy stems.
• A canopy is a roof-like layer of leaves over a forest.
• Epiphytes are climbing plants found in a forest.

Thicket Biome

• Occurs in finger-like projections along the coasts of KwaZulu-Natal, the Eastern Cape, and some other areas.
• Most of the thicket biome is located in river valleys.
• Consists of many short trees, low intertwining shrubs, and vines.
• Vines often have spines for protection.

Desert Biome

• Mainly occurs as the Namib Desert.
• The Namib Desert is found along the west coast of Namibia.
• Some scientists believe that the Succulent Karoo and parts of the Savanna Biome form parts of the Desert Biome.
• Shrubs grow in areas with water drainage.
• Welwitschia is an example of a desert shrub, and a few trees may also grow.

Additional Terminology

• Mutualism: A symbiotic relationship where both organisms benefit
  • Lichen is an example of mutualism.

Further tasks

• Identify the earth part where living organisms are found.
• Identify the soil and rocks of the upper layers of the earth’s surface.
• Identify a region with a distinct climate and all the organisms living there.
• Identify Southern Africa's largest biome.
• Describe Species occurring only in one area.
• The name given to the vegetation found only in the Western Cape.