6.7 How Humans Reduce Biodiversity

Question 1

Biodiversity is a combination of three different factors. What are these?

Answer 1

• The diversity (variety) of living organisms in a particular area.
• The diversity of different genes and alleles in a particular area (also known as genetic diversity).
• The diversity of different ecosystems in a particular area

Question 2

Why is biodiversity important? (3)

Answer 2

It means that if the environment changes in some way, there’s a good chance that at least some species and ecosystems will be able to survive. It also means that we humans can get the most out of the world’s resources. For example, there are many species of animals that are pollinators and help us pollinate fruits and vegetables. Also, more than half of new medical drugs are derived from living organisms in some way.

Question 3

Humans have a big impact on the ecosystems around us. The impact humans have on ecosystems has changed a lot in the last couple of centuries. What factors is this largely due to?

Answer 3

• An increasing human population - the human population on Earth has grown hugely over the last 200 years and is continuing to rise. Many more people on the planet means we need to take up more land and use more resources in order to survive.
• Industrialisation - due to improvements in technology and the need for more goods and services, there is now much more industry on the planet than there was a couple of centuries ago. This means we are using more raw materials (e.g. oil, wood) and more energy to manufacture goods. It also means we’re creating more waste products, which can lead to more pollution.
• Globalisation - as communication and transport have improved, different countries have become more connected with each other. This means that countries are able to buy and sell products from each other more easily and the same companies are able to operate in several different countries.

Question 4

Describe how increased human population, industrialisation and globalisation all have an effect on biodiversity

Answer 4

• Habitat destruction - human activities (e.g. farming, building, quarrying) reduce the amount of land and resources available to other animals and plants, which can reduce biodiversity in an area. Species will die or be forced to migrate to elsewhere.
• Waste - the increasing population and industrialisation means we’re producing more waste, which can damage ecosystems in many ways. For example, sewage and toxic chemicals from industry and agriculture can pollute lakes, rivers and oceans, affecting the plants and animals that rely on them for survival. Also, the burning of fossil fuels release chemicals like sulfur dioxide, which can directly harm organisms or cause acid rain.
• Shared resources - increasing globalisation means that resources can be shared between many countries. Unfortunately, this can lead to a loss of biodiversity. For example, large companies can sell the ‘best’ varieties of seeds to farmers in many different countries, reducing the number of seed varieties used for crops globally and therefore reducing global biodiversity.

Question 5

How could the loss of a species in an ecosystem have knock-on effects for other organisms?

Answer 5

It can negatively impact food chains, which could cause a further decrease in biodiversity.