Deforestation

Question 1

Give 4 reasons for deforestation.

Answer 1

1. Teak and Mahogany are expensive so are targeted, and other trees get damaged in the process.
2. New roads are built
3. Timber is used for building, fuel, paper and packaging
4. Land is cleared for farming - biofuels or grazing

Question 2

Give 6 consequences of deforestation.

Answer 2

1. Soil erosion
2. Lowland flooding
3. Diminished soil quality
4. Less rainfall
5. Habitat loss + reduction of species
6. Atmospheric effects

D HALLS

Question 3

Explain how deforestation causes soil erosion.

Answer 3

On higher slopes it allows heavy rain to sweep exposed topsoil down, and what is left isn’t fertile.

Question 4

Explain how soil quality is diminished by deforestation.

Answer 4

Without trees, water can’t transpire from them so water evaporates from soil.

Question 5

How does too much water affect soil? (3)

Answer 5

1. Deforested soil is wetter - it fills up airspaces so oxygen availability for roots decreases.
2. Wet soil takes longer to warm up so the cold soil means germination and root activity is reduced
3. Cold damp soil favours the growth of denitrifying bacteria, so soil loses its fertility.

Question 6

Why is there less rainfall due to deforestation?

Answer 6

There is no transpiration from trees and evaporation from the soil is slower.

Question 7

How does deforestation affect the atmosphere?

Answer 7

With less trees, less CO2 is removed from the atmosphere. When cut trees are burnt or left to decay, they release CO2.

Question 8

What does ‘slash and burn’ mean in reference to forest management?

Answer 8

Cutting and burning a small area of forest, then growing crops there as the ash makes the soil fertile. Then when it becomes infertile, leaving it to regenerate.

Question 9

What is coppicing?

Answer 9

Where they cut trees down to a stool of a few centimetres, so new shoots emerge from buds which grow into poles (which get thicker over the years).

Question 10

Why is a long rotation for coppicing advantageous?

Answer 10

Coppiced plants can regenerate over time, and as there are many years between harvesting a variety of habitats develop.

Question 11

Why is selective cutting advantageous?

Answer 11

It is valuable on steep slopes where total removal would leave soil vulnerable to erosion.
It helps to maintain nutrients in soil.

Question 12

Give 3 examples of good forestry practice.

Answer 12

1. Planting trees far away to avoid intra-specific competition
2. Controlling pests + diseases so they grow well
3. Cutting a similar number of trees each year for long periods of time.

Question 13

Why is cutting a similar number of trees each year for long periods of time good for forests?

Answer 13

It allows the trees ecosystem to be maintained. Habitats remain intact and species are able to live even though timber is being removed.