Question | Answer |
List 4 reasons why the quantity of food produced bu agriculture has increased enormously in the last century. | More mechanization - using tractors instead of animals, using fertilisers, using herbicides, using pesticides, selective breeding. |
Explain what is meant by monoculture. | A large area on which a single variety of crop is grown |
Describe 2 problems caused by monocultures. | 1. They reduce biodiversity.
2. They can lead to increases in sizes of pest populations. |
Describe 2 problems cause by intensive livestock farming. | 1. It requires high inputs ( a lot of money has to be spent on buying food for the animals).
2. Itâs easy for disease to spread among the animals, so antibiotics may be used, increasing the strains of bacteria developing. |
Outline the main ways in which humans destroy habitats. | By cutting down forests, polluting land & water, mining, building houses, roads & industries etc |
Explain how extensive deforestation can affect the amount of carbon dioxide in the air. | Growing trees take CO from the air for photosynthesis. If trees are removed, then less CO is removed. If the trees are burnt, this produces CO that goes into the air. |
Explain how deforestation can cause soil erosion. | Without trees rain can easily wash the soil down the slope. Trees intercept raindrops as they fall, reducing the force with which they hit the soil. Without trees, rain hits the ground harder so that soil is loosened & washed away. |
Explain how deforestation can cause flooding. | Trees absorb water from the soil. Without trees less water is absorbed & more runs off the surface of the land increasing soil erosion & flooding. |