Australia: Climate, Natural Vegetation, Wildlife; Forest and Minerals

However, based on typical geography curricula for this level, the chapter likely covers the following key aspects, which I can summarize generally if you don’t have the specific text available:

Climate:

• Factors Influencing Climate: Latitude (ranging from tropical to temperate), prevailing winds, ocean currents, and the Great Dividing Range.
• Climate Zones: Likely discusses tropical (north), arid/semi-arid (interior), temperate (south and southeast), and Mediterranean (southwest) climates.
• Rainfall Patterns: Focus on the generally low rainfall across much of the continent, with higher rainfall in coastal areas, especially the east.
• Temperature Variations: Seasonal variations and regional differences in temperature.

Natural Vegetation:

• Adaptation to Climate: How vegetation types are adapted to different climate zones and rainfall amounts.
• Major Vegetation Zones: Likely covers:
  • Tropical rainforests (northeast)
  • Eucalypt forests (various types across the east and southwest)
  • Savannas/Grasslands (tropical north and interior)
  • Deserts (interior)
  • Temperate forests (southeast and Tasmania)
  • Mediterranean vegetation (southwest)
• Unique Flora: Emphasis on endemic species like eucalyptus and acacia.

Wildlife:

• Isolation and Endemism: How Australia’s long isolation led to unique animal evolution.
• Major Animal Groups: Focus on marsupials (kangaroos, koalas, wombats), monotremes (platypus, echidna), unique birds (emus, kookaburras), reptiles, and introduced species.
• Adaptations to Environment: How wildlife is adapted to different climates and vegetation zones.

Forests:

• Types of Forests: Native eucalypt forests (hardwood), rainforests, and introduced pine plantations (softwood).
• Economic Importance: Timber industry, paper production.
• Conservation Efforts: Issues of deforestation and the importance of sustainable forestry.

Minerals:

• Rich Mineral Resources: Australia as a major global producer of various minerals.
• Major Minerals: Likely covers iron ore, coal, gold, bauxite (for aluminum), and other significant resources like uranium, diamonds, and natural gas.
• Location of Mineral Deposits: General regions where major minerals are found.
• Environmental Concerns: Impact of mining on the environment and rehabilitation efforts.

DISCUSS

Discuss the role of the Eastern Highlands in the climate of Australia.
Ans:

1. Orographic Rainfall (Rain Shadow Effect): This is arguably the most significant impact. As these prevailing easterly winds laden with moisture encounter the rising slopes of the highlands, they are forced to ascend. This results in a wetter climate along the eastern coastal strip and the eastern slopes themselves, supporting more lush vegetation and higher population densities.

This process creates a rain shadow, resulting in significantly lower rainfall and a much drier climate across the western slopes and the vast interior plains of Australia. This rain shadow effect is a primary reason why much of inland Australia is arid or semi-arid.  

2. Temperature Modification: The altitude of the Eastern Highlands also influences temperature. Generally, temperatures decrease with increasing elevation. The higher elevations of the range experience cooler temperatures compared to the coastal lowlands to the east and the inland plains to the west. This can lead to localized cooler microclimates within the highlands, supporting different types of vegetation and providing refuge for some species. In some of the higher parts of the southern sections, snowfall can even occur during winter.  
3. Influence on Wind Patterns: The Eastern Highlands act as a physical obstruction to air movement. They can deflect or channel winds flowing across the continent. While the prevailing winds are easterly, the presence of the range can influence local wind patterns, creating variations in wind speed and direction on either side. This can have implications for local weather conditions and the distribution of moisture.
   
4. Limited Barrier to Cold Southern Air: While the range primarily influences east-west airflow and rainfall, it also offers some limited barrier to cold air masses moving northward from the Southern Ocean, particularly in the southern parts of the highlands. The higher elevations can help to moderate the penetration of very cold air further inland, although this effect is less pronounced than the impact on easterly winds.

THINK AND ANSWER

Why do we not find marsupials like kangaroo and wombat in other parts of the world ?
Ans:

The confinement of kangaroos and wombats, along with the majority of Australian marsupials, to Australia is primarily due to a unique interplay of evolutionary pathways and prolonged geographical isolation.

Marsupials originated and dispersed across the ancient landmass of Gondwana, which included present-day Australia. As the continents separated, Australia drifted apart and remained isolated for an extensive period.

On the other landmasses, placental mammals evolved and, possessing a more efficient reproductive strategy, often outcompeted marsupials. While some marsupial species persisted in South America, their diversification was limited compared to the evolutionary success of placentals.. This absence of significant placental competition allowed them to diversify and adapt to a wide range of ecological roles, resulting in the rich variety of marsupials present today. The physical barrier of the surrounding oceans largely prevented the widespread introduction of placental mammals to Australia, enabling marsupials to flourish and evolve along their own distinct trajectories. While a small number of marsupial species exist outside this region, their diversity and ecological influence are minimal in comparison to Australia.

EXERCISES

A. Match the columns

Ans:

B. Identify who I am.

Question 1.
I am an animal that lives entirely on the juicy leaves of the gum tree.
Ans:
Koala

Question 2.
I am a wild dog found in Australia.
Ans:
Dingo

Question 3.
I am a mammal that lays eggs.
Ans:
Platypus

Question 4.
I am a big Australian bird but I cannot fly.
Ans:
Emu

Question 5.
I have a beautiful fan-tail and I can mimic very well.
Ans:
Cassowary

Question 6.
I am a male bird who likes to attract female birds by building intricate and decorative nests.
Ans:
Bower

Question 7.
I am popularly called the ‘laughing jackass’.
Ans:
Kookaburra

D. Answer the following questions in one or two paragraphs.

Question 1.
Name the factors that influence the climate of Australia. Elaborate any two.
Ans:

Australia’s climate is shaped by several key factors:

• Latitude: Ranging from tropical to temperate zones, latitude dictates solar radiation and thus temperature and seasonality variations across the continent.
• Ocean Currents: Warm currents like the East Australian Current bring warmer temperatures and rainfall to the east coast.
• Prevailing Winds: South-East Trade Winds bring moisture and rainfall to the east coast. Westerlies bring winter rainfall to the south.
• The Great Dividing Range: This eastern mountain range causes orographic rainfall on its windward side and a rain shadow effect, leading to aridity in the interior.
• Distance from the Sea: Coastal areas have more moderate temperatures and higher rainfall than inland areas, which experience greater temperature extremes and lower precipitation.
• El Niño-Southern Oscillation (ENSO): This Pacific Ocean climate pattern significantly affects Australia’s rainfall and temperature from year to year.
• Indian Ocean Dipole (IOD): Sea surface temperature differences in the Indian Ocean also influence rainfall patterns, particularly in southern and central Australia.

Elaboration on Latitude and the Great Dividing Range:

1. Latitude:

Australia’s extensive north-south spread, from approximately 10°S to 44°S, directly influences the amount of solar energy received.

• Tropical North: Closer to the equator, this region receives intense sunlight year-round, resulting in consistently high temperatures and distinct wet and dry seasons with monsoonal rainfall.
• Subtropical Centre: This zone has hot summers and mild to cool winters with generally low and variable rainfall, leading to arid and semi-arid conditions. The Tropic of Capricorn passes through it.
• Temperate South: Further south, this region experiences more pronounced seasonal temperature variations, with warm summers and mild to cool winters. Rainfall patterns vary, with some areas having year-round precipitation and others a Mediterranean climate of dry summers and wet winters.

The varying solar radiation due to latitude also drives air pressure systems and wind patterns, influencing rainfall distribution.

2. The Great Dividing Range:

This extensive mountain range along Australia’s east coast significantly impacts the climate of eastern Australia, primarily through its effect on rainfall.

• Orographic Rainfall: Easterly trade winds carrying moisture from the Pacific Ocean are forced upwards by the range. As the air rises and cools, it releases significant rainfall on the eastern (windward) slopes, creating a wetter coastal and highland climate.
• Rain Shadow Effect: This leads to a significant reduction in rainfall, creating a rain shadow that contributes to the arid and semi-arid conditions of inland eastern Australia. This effect creates a stark contrast in climate and vegetation across the range.

Question 2.

The Western Plateau region of Australia is mainly a desert. Why ?

Ans:

The predominantly desert conditions of Australia’s Western Plateau are a result of several interacting geographical and climatic factors:

• Subtropical High-Pressure Zone: A significant part of the plateau lies within this zone, characterized by descending, warming, and drying air that inhibits cloud formation and rainfall.
  
• Inland Location: Its considerable distance from oceans means that rain-bearing winds lose much of their moisture before reaching the interior.
  
• Rain Shadow Effect: The Eastern Highlands intercept moisture from Pacific winds, resulting in much drier air reaching the Western Plateau.
  
• Ocean Current Influence: While the Leeuwin Current is warm, overall atmospheric patterns lead to less moisture pickup off the west coast compared to the east.
  
• Lack of Topographical Barriers: The plateau’s generally flat terrain lacks significant mountains to force air upwards and generate orographic rainfall.
  
• High Evaporation: Even limited rainfall quickly evaporates due to high temperatures and low humidity.

Question 3.

Briefly describe the climate and vegetation of the south-eastern and south-western coasts of Australia.

Ans:

South-Eastern Coast:

• Climate: Primarily temperate with warm, humid summers and mild, wet winters. Rainfall is generally reliable and distributed throughout the year, often influenced by the South-East Trade Winds and cold fronts associated with the Westerlies.
• Vegetation: Characterized by temperate forests, including eucalypt forests (various species like gum and stringybark), rainforests in wetter areas, and woodlands. The vegetation is generally lush and diverse due to the consistent rainfall.

South-Western Coast:

• Climate: Exhibits a Mediterranean climate with hot, dry summers and mild, wet winters. Rainfall is concentrated in the winter months, influenced by the Westerlies.
• Vegetation: Dominated by sclerophyllous vegetation adapted to the hot, dry summers and nutrient-poor soils. This includes eucalypt forests (like jarrah and karri), woodlands, and heathlands with diverse species of shrubs and wildflowers, known for their high levels of endemism.

Question 4.

What are marsupials ? Describe any one marsupial.

Ans:

Marsupials: Mammals with a unique reproductive system where underdeveloped young are born and typically mature in a pouch. Found mainly in Australia and the Americas.

Kangaroo: Large Australian marsupial known for powerful hopping, strong tail, and the female’s pouch for young (joey). Herbivorous and social animals. The largest living marsupial.

Question 5.

What are monotremes ? Give examples.

Ans:

Monotremes are a unique order of mammals that lay eggs, unlike all other living mammals. They also possess a single opening, the cloaca, for their urinary, digestive, and reproductive systems, similar to reptiles and birds.

There are only five living species of monotremes, all found exclusively in Australia and New Guinea:

Examples:

1. Platypus (Ornithorhynchus anatinus): A semi-aquatic mammal with a duck-like bill (equipped with electroreceptors), beaver-like tail, webbed feet, and venomous spurs in males.
   
2. Short-beaked Echidna (Tachyglossus aculeatus): A spiny mammal with a long snout and tongue specialized for eating ants and termites.
   
3. Long-beaked Echidnas (Zaglossus spp.): Three species found in New Guinea (Western, Eastern, and Sir David’s), larger than short-beaked echidnas with a longer, down-curved snout, primarily eating earthworms and insect larvae.
   

These five species are the only monotremes, making them a distinct and evolutionarily important group, showcasing a blend of reptilian and mammalian traits.

E. Map work
Study the map given here and answer the questions (lines indicate the different climatic regions) : (On Textbook page 149)

Question 1.
Describe the vegetation of region C.
Ans:
Temperate Grassland

Question 2.
What are the most outsanding characteristics of the climate of region B ?
Ans:
Tropical Monsoon

Question 3.

On the map, draw the South-East Trade Winds with red

Ans:

Question 2.
Which animal survivies by eating the leaves of this tree?
Ans:
The koala is the animal that primarily survives by eating the leaves of the eucalyptus tree.

Their digestive system is uniquely adapted to break down the toxins and tough fibers in these leaves, which are poisonous to most other animals. They possess a long caecum with specialized bacteria that aid in this process, allowing them to extract the limited nutrients.

While their diet mainly consists of eucalyptus, koalas may occasionally eat leaves from other native trees. However, eucalyptus remains their primary food source and habitat.