Asia - Climate and Natural Vegetation and Wildlife Chapter Notes | Geography for Grade 9 PDF Download

Introduction

Climate

• Asia has varied climates due to its oceans, mountains, deserts, and wind patterns.
• Regions far from oceans and seas face extreme continental climates.
• Coastal areas enjoy milder, maritime climates.
• Mountain ranges block rain-bearing clouds from the south and cold winds from the north.

Monsoon

• Monsoons are winds that change direction every six months.
• In summer, winds blow from sea to land, bringing moisture.
• In winter, winds move from land to sea, often dry.
• Monsoons create wet and dry seasons, especially in the Indian Ocean region.
• Summer and winter monsoons shape the climate of India and South-East Asia.

Summer Monsoon

• From March to September, the sun heats the Northern Hemisphere.
• By June, the sun is over the Tropic of Cancer, raising temperatures to about 32°C in most of Asia.
• Hot land air rises, creating low pressure.
• Moisture-laden winds from high-pressure seas move to land.
• Heavy rainfall occurs in countries like India, Sri Lanka, Myanmar, Thailand, Malaysia, Indonesia, Laos, Vietnam, China, and parts of Japan.

Winter Monsoon

• From October to March, the sun’s rays slant over the Northern Hemisphere.
• The sun is directly over the Tropic of Capricorn, cooling the land.
• Heavy, cold air creates high pressure over the land.
• Dry winds blow from land to warmer seas and oceans.
• Most of Asia stays dry, but some winds pick up moisture over oceans.
• Winter rainfall hits South-East Asia, Japan, south-eastern India, and northern Sri Lanka.
• Parts of South and West Asia get winter rain from Mediterranean temperate cyclones.

Factors Affecting the Climate of Asia

Latitudinal Extent and Size

• Asia spans from 10°S to 80°N, causing diverse climates.
• Climates range from hot, wet equatorial to cold arctic types.

Distance from the Sea

• Coastal regions have maritime climates with mild temperatures.
• Inland areas face extreme heat in summer and cold in winter.

Alignment of the Mountain Ranges

• Most Asian mountains run east-west.
• The Himalayas block cold Siberian winds from reaching the south.
• They also stop moisture-bearing winds from the south, limiting rain in Central Asia.
• The Aravalli Hills align with monsoon winds, so Rajasthan gets little rain.

Ocean Currents

• Warm currents like the Kuroshio raise temperatures along Japan’s coast.
• Cold currents like the Oyashio cool Japan’s coastal areas.

Major Climatic Regions of Asia

Tundra Region

• Features long, cold, dry, snowbound winters and short, cool summers.
• Some snow melts in summer.
• Northern coast of Asia is in this region.

Taiga Region

• Has cold winters and warm summers.
• Central Siberia is part of this region.

Temperate Region

• Experiences warm summers with rain and cool winters with snow.
• Includes North-East Asia: Japan, North Korea, South Korea, Mongolia, most of China, and Russian Siberia.

Monsoon Region

• Has a dry cool season and a wet warm season.
• Mumbai, India, gets over 2000 mm (80 inches) of rain yearly, but December to February is dry.
• Summer brings warm, moist winds from the Indian Ocean, causing heavy rain.
• Winter winds blow from land to sea, bringing little or no rain.
• China has a similar climate but with cooler temperatures.

Equatorial Region

• Sees high, well-distributed rainfall year-round.
• Temperatures vary little, except where trade winds shift and dry some areas.
• Includes Indonesia, Sri Lanka, Malaysia, and the Philippines.

Desert Region

• Marked by very low rainfall (less than 250 mm) and extreme temperatures.
• Found in Central Asia, Saudi Arabia, Iran, north-west India, and south-east Pakistan.
• Gobi and Taklamakan deserts face intense summer heat, like tropical deserts.

Temperate Grasslands (Steppes)

• Have cold winters and warm summers.
• Lie north of deserts, covered in short grass.
• Home to antelope and deer.

Mediterranean Region

• Features hot, dry summers and cool, wet winters.
• Includes Turkey, Syria, and coastal Israel and Lebanon.
• Istanbul, Turkey, has a hottest month at 23°C and coolest at 6°C.
• Total yearly rainfall is 736 mm, with 500 mm from November to March.

Natural Vegetation and Wildlife

• Asia’s vegetation varies by region, based on climate and flora.
• Tundra and taiga are in North Asia.
• Deciduous forests and steppes are in Central, West, and East Asia.
• Highland and mixed forests are in Central Asia.
• Equatorial rainforests are scattered across South-East Asia.
• Desert vegetation is in West Asia.
• Tropical monsoon forests are mainly in the Indian subcontinent.

Tundra

• Tundra means ‘marshy plain’ in Russian.
• Arctic tundra is near the North Pole; alpine tundra is on high, cold mountains like Mt. Everest.
• Has cold, treeless plains with frozen subsoil.
• Lichens, mosses, sedges, and grasses grow in better spots.
• Summer snowmelt forms bogs and shallow lakes.
• Insects thrive in bogs, attracting migratory birds.
• Some plants bloom briefly in summer.
• Animals include polar bears, reindeer, arctic foxes, seals, and walruses.

Taiga

• Stretches from Siberia to northern Japan.
• Has coniferous trees with needle-like leaves, deep roots, thick bark, and cone-borne seeds.
• Common trees are pine, spruce, fir, larch, and cedar.
• Animals include sable mink, polar fox, bear, lynx, and squirrel.

Deciduous Vegetation

• Found in parts of Korea, China, Russia, and Japan.
• In China, includes North-east China Plain deciduous forest and Manchurian mixed forest.
• In Korea, known as Central Korean deciduous forest.
• Trees include oak, camellia, magnolia, camphor, beech, and chestnut.
• Animals include monkeys, foxes, parrots, peacocks, and pheasants.

Tropical Deciduous

• Split into tropical deciduous and tropical monsoon forest regions.
• Tropical monsoon forests get slightly more rain.
• Found in India, Pakistan, Bangladesh, Myanmar, Thailand, Vietnam, Laos, Cambodia, and southern China.
• Trees face a long dry season, shedding leaves, then regrow them in the rainy season.
• Common trees are teak, sal, shisham, and mango.
• Drier areas have bamboo thickets, grasses, and thorny bushes.
• Animals include elephants, monkeys, snakes, bears, deer, apes, lions, tigers, leopards, and various birds.

Desert

• Found in the Arabian Peninsula, Tibet, Mongolia, and steppe lands near the Caspian Sea.
• Plant cover is sparse, with moisture-resistant, waxy, deep-rooted thorny shrubs and stunted trees.
• Dry grass clumps are scattered.
• Date palms and sparse vegetation grow near oases.
• Animals include camels, horses, mules, lizards, and insects.

Equatorial Rainforest

• Located in Malaysia, Indonesia, and southern Philippines.
• Features dense hardwood trees with broad leaves.
• Common trees are mahogany, ebony, rosewood, cinchona, coconut, and rubber.
• Creepers, climbers, tall grasses, and bamboo make forests dense.
• Little sunlight reaches the ground due to the leaf canopy.
• Animals include monkeys, apes, various birds, and reptiles like lizards, snakes, and crocodiles.
• The Komodo dragon, the world’s biggest lizard, lives here.