The Tropical Envrionment

Question 1

What are the main deserts and how can we classify them?

Answer 1

Deserts can be classified into tropical deserts and temperate deserts, with tropical deserts being located nearer the equator within 30N/S and temperate deserts being located at higher latitudes.
Tropical deserts: Sahara desert, Arabian desert, Great Australian Desert, Thar
Temperate deserts: Gobi desert, Takla Makan desert, Patagonian desert, Great Basin

Question 2

In which countries are the Gobi desert and Takla Makan desert located?

Answer 2

China and Mongolia

Question 3

What are 3 countries that are covered by the Sahara desert?

Answer 3

Egypt, Sudan, Chad (North Africa)

Question 4

What are the major tropical rainforests and where are they located?

Answer 4

Amazon rainforest: Brazil, Peru, Bolivia (South America)
Congo Basin: Congo, Central African Republic, Gabon (Central-western Africa)
South-east Asia: Malaysia, Indonesia, Thailand (SE Asia)

Question 5

What are 5 examples of major biomes?

Answer 5

Rainforest, grassland, aquatic, desert, tundra

Question 6

What are the factors that affect the mean annual temperature and annual range of temperature of a place?

Answer 6

Latitude/angle of the sun: a lower latitude causes a higher angle of the sun with higher concentration of sunlight, which contributes to higher annual mean temperature
Prevailing winds: onshore winds carry moisture and helps to moderate the temperature, causing a lower annual temperature range; meanwhile, offshore winds blow from inland and carry less moisture, resulting in a larger dirunal temperature range
Landmass/land and sea: land heats up and cools down more rapidly than the sea, which causes a higher annual range of temperature.

Question 7

What are factors that affect the annual rainfall of a place?

Answer 7

Prevailing winds: onshore winds carry more moisture, making it more likely to rain
Relief rainfall/rain shadow: some places are located on/behind the leeward side of mountains, which lowers the annual rainfall.

Question 8

What is the formation of convection rain?

Answer 8

1. The sun heats up the surface of the Earth.
2. Hot air expands and rises.
3. As hot air rises, it cools.
4. As air cools, relative humidity of air increases and air becomes more saturated with water.
5. At condensation level, condensation occurs and clouds form.
6. Air cools and sinks, continuous convection currently occur, creating thick cumulonimbus clouds.

Question 9

What are the characteristics of convection rain?

Answer 9

It commonly occurs in tropical regions and continental interiors during summer. It usury occurs in late summer when the convection current is the strongest. The duration of this type of rain is short and it is often accompanied by thunderstorms.

Question 10

What is the relationship between rainfall and vegetation?

Answer 10

As the amount of annual rainfall decreases, the vegetation cover changes room dense to sparse. There are fewer species of plants and fewer tree layers in vertical structure. The plants become shorter in height no there are fewer trees. The savanna is a traditional region between the rainforest and the desert.
The hot and wet equatorial climate supports dense forests. Many different kinds of plants grow in the hot and humid environment. Tropical rainforests are homes of over 50% of the world’s plants and animals, over 5000 kinds of plants species, and 1/3 of the world’s bird species, so the tropical rainforests are said to be rich in biodiversity. Plants grow continuously throughout the year because there is no cold and no dry seasons. Therefore, the forests are evergreen.

Question 11

What are the characteristics of the emergents?

Answer 11

The emergents belong to the emergent layer of the rainforest, which is the tallest layer, with trees having height up to 50m. The trees are tall, straight, and have smooth trunks. They are umbrella-shaped for full exposure to sunlight. The have less branches to reduce obstruction when reaching sunlight and to concentrate energy on height growth.

Question 12

What are the characteristics of the main canopy?

Answer 12

The main canopy belongs to the second layer in height in the rainforest, with trees being approximately 20-35m in height. The trees have oval-shaped crowns that create a close and continuous canopy that blocks sunlight from penetrating down to the forest floor.

Question 13

What are the characteristics of the under canopy?

Answer 13

The under canopy is the third layer in the rainforest, consisting of young trees with height seldom exceeding 15m. They have conical-shaped crowns and die easily due to insufficient sunlight.

Question 14

What are the characteristics of the shrub layer?

Answer 14

The shrub layer is the fourth layer of the rainforest, with plants being less than 5 metres tall. Most of them are woody shrubs with large leaves, and thy sprawl across the rainforest floor for maximum surface area to get sunlight.

Question 15

What are the characteristics of the ground level?

Answer 15

The ground level of the rainforest consists of little undergrowth like mosses and fungi. There is little availability of sunlight. There is a humid and rotting layer of leaves and animals called litter, which is important for providing nutrients.

Question 16

What are features of leaves in the rainforest?

Answer 16

The leaves are broad and large, which provides a larger surface area to absorb more sunlight. They are dark green, which shows that there is an abundance of chlorophyll to increase the rate of photosynthesis. They have drip-tips and a waxy surface to enable water to run off easily, reducing damage to the leaf.

Question 17

What are the features and functions of the roots in the rainforest?

Answer 17

Aerial roots animists absorption foster or nutrients in the air. Buttress roots provide sturdy support for the trees for them to reach taller and get more sunlight. Shallow extensive roots enables the trees to collect more nutrients or rainfall in thin soil with large surface area.

Question 18

What are the features and functions of the trunks of trees in the rainforest?

Answer 18

There are few branches to reduce obstruction in trying to reach sunlight and passing through the dense canopy layer. Trees have straight trunks to focus nutrients on attaining height and reaching sunlight.

Question 19

What are the special plants in the rainforest?

Answer 19

Epiphytes, climbers, stranglers, parasites

Question 20

What are the characteristics of epiphytes?

Answer 20

They are small shrubs or herbs attaching themselves to trunks or branches, with one example being orchid. They grow in the canopy layer for sunlight, are harmless to the host plant, and have aerial roots.

Question 21

What are the characteristics of climbers?

Answer 21

They are woody plants that climb along other trees as support or for sunlight, with one example being lianas.

Question 22

What are the characteristics of stranglers?

Answer 22

They start their lives as epiphytes and send roots to the ground, with an example being the strangling fig. However, unlike epiphytes, they eventually block the sunlight and kill the tree.

Question 23

What are the characteristics of parasites?

Answer 23

They do not produce their own food, and grow on other host plants and live by taking nutrients from the host plants, with an example being the corpse flower.

Question 24

What are the characteristics of plants in deserts?

Answer 24

The air in deserts is often quite dry because the humidity of the air is usually very low. Low annual rainfall in deserts means there is insufficient rainfall for vegetation growth. The dryness in deserts results in a sparse vegetation cover.
Desert landscapes are often barren lands with only sparse distribution of vegetation. Very few plants can grow because they need more water. Short, rough shrubs and low trees are found here as they need less water.

Question 25

What are the characteristics and functions of cacti?

Answer 25

They have spines that lowers surface area for transpiration, resulting in less water loss. Spines also protect cacti from predators. They have waxy skin, which minimises water loss and provide insulation, with large stems and thick fleshy skin for larger storage of water.

Question 26

What are the characteristics and functions of acacia trees?

Answer 26

They have deep tap roots to reach the water table and get water. They also have horizontally growing roots that maximises the surface area, and therefore increases the chance of absorbing precipitation and nutrients from the thin top soil layer. In addition, they have small leaves which reduce transpiration and water loss.

Question 27

What are the characteristics and functions of the rose of Jericho?

Answer 27

They have dormant seeds and can survive without water for 3 years, which enables them to wait and propagate when correct moisture conditions are available. They also can shrink and dry down to 3% of their mass, which makes them durable and. Able to survive in extremely harsh conditions.

Question 28

How does the climate of deserts affect the vegetation growth?

Answer 28

Winds are usually strong in deserts, and sandstorm or dust storms will occur in the presence of strong winds. The thin topsoil with nutrients is blown by wind, which hinders the development of soil. Therefore, the soil in deserts remains thin. This factor, along with other factors like low unreliable rainfall and little cloud cover, cause the desert to be a barren harsh land difficult for vegetation growth.

Question 29

What are oases and what is one example?

Answer 29

There may be areas where the water table meets the surface of a desert. Since there is a water supply, plants can grow well and oasis may form. One examples of oases is the Siwa Oasis.

Question 30

What are the characteristics of soil in tropical rainforests?

Answer 30

The tropical rainforest soil may contain few nutrients due to quick decomposition by the fungi which prevents accumulation of bacteria. The nutrients are rapidly uptakes by vegetation and may be washed out by the high rainfall. The surface of the soil is covered with thick litter, and there d a thin dark humus layer below, followed by the surface, subsoil, and substratum layers.

Question 31

What are the characteristics of soil in deserts?

Answer 31

It is a mosaic of closely packed pebbles and boulders with a weak humus-mineral structure. It is dry, brown to reddish-brown, with variable accumulations of clay, calcium, carbonate, and soluble salts.

Question 32

Why are the tropical rainforests important in terms of biodiversity?

Answer 32

Rainforests are the world’s largest pharmacy. Plants in rainforests account for raw materials to make 1/4 of western medicines, while around 70% of plants considered to have anti-cancer powers are exclusive to the Amazon. There are more than 25000 plant species in the rainforest in south-east asia, 100000 plant species in Congo Basin, and about 6000 flora species in the rainforest of French Guiana.

Question 33

Why are rainforests important in terms of regulating water and air?

Answer 33

Rainforests are lungs of the Earth that stabilise the Earth’s climate through undergoing photosynthesis and absorbing carbon dioxide while releasing oxygen. It also helps to regulate water resources by storing over half of Earth’s rainwater alone by the Amazon. They continually recycle huge quantities of water to feed rivers and lakes.

Question 34

What is the difference between intensive and extensive farming?

Answer 34

Intensive farming refers to putting a lot of resources to maximise productivity