Area of Hot Desert

Question 1

Introduction

Answer 1

The Sahara is the world’s largest hot desert. It has a very interdependent ecosystem made up of numerous abiotic and biotic factors.

Question 2

Climate

Answer 2

1) High daily temperatures often reach 40 degrees Celsius year-round with an annual temperature range of 20 degrees Celsius between January and July.
2) There is a very high diurnal temperature range, scorching heat during the day and very low temperatures at night.
3) Very little annual rainfall (<150mm).

Question 3

Soils

Answer 3

1) Either rocky or sandy, and very porous, so water percolates quickly downwards after rain. This means soils are very dry.
2) Very thin and infertile due to little organic matter (decomposing plant litter)
3) Often baked hard by the sun to form a brittle crust

Question 4

Plant adaptations

Answer 4

1) Many plants have deep vertical tap roots to obtain water from deep underground below the water table
2) Cacti have spines with a waxy cuticle to minimize water loss and prevent predators from eating them
3) Succulents store water in their stems, leaves, roots, or fruits. They have thick waxy skin to prevent water loss via transpiration.
4) Rapid bloom and germinate cycle to take advantage of the intermittent rainfall.

Question 5

Animal adaptations: camels

Answer 5

1) Have long eyelashes, hairy ears and closing nostrils to keep out sand during storms.
2) Thick eyebrows which stick out to shade eyes from sun.
3) Wide feet to reduce pressure on the sand to prevent them from sinking in.
4) Body temperature can change to avoid losing water through sweating.
5) Their fur is camouflage and helps keep them warm at night.

Question 6

Animal adaptations: Fennec Fox

Answer 6

1) Large ears to radiate excess heat and regulate body temperature.
2) Nocturnality means they don’t have to hunt during the day when it is hot.
3) Hairy feet to prevent sunburns.