Biodiversity

Define biodiversity

*The measure of all the different plants, animal and fungus and other microorganism species worldwide, the genes they contain, and the ecosystems of which they form a part.* 

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A **measure of variation** found in the living world. 

What are the three types of biodiversity?

Habitat (range of habitats in which different species live is known as)

Species (range of organisms in a habitat contributes to this)

Genetic (variation between individuals belonging to the same species)

Which of the following communities have more biodiversity and why? Refer to species richness and species evenness

Community 1 has more biodiversity

Richness: equal in both (number of plant species)

Evenness: 1 greater (degree to which the species is represented)

What 4 main areas affect biodiversity?

1. Human population
2. Extinction
3. Agriculture
4. Climate change

How does human population growth affect biodiversity?

1. We have learned to use the environment to our advantage
2. We alter ecosystems to provide ourselves with food
3. We destroy habitats
4. We are using more of the Earth’s resources
5. We pollute the atmosphere

How does agriculture affect biodiversity?

1. We clear natural vegetation
2. We reduce the size of habitats
3. We reduce the populations of species
4. This reduces genetic diversity
5. We are leaving isolated and fragmented populations

How do monocultures affect biodiversity?

•Crop consisting of one strain of the species

•Limited genetic diversity

•Easier to harvest the product

•Example – palm oil plantations

How does selective breeding affect biodiversity?

•Farmers select traits such as rapid growth or high protein content

•Other characteristics may be ignored

•Genetic diversity is reduced

•Genetic erosion occurs – loss of variety of the species

How does climate change affect biodiversity?

•Climate change means species are less able to adapt

•The alternative is that they move and follow climate patterns that suit them

•Slow migrations of populations

•These can be blocked by human activity, bodies of water, mountains etc.

•Domesticated plants and animals are most at risk, food will decrease and farmers will need to change the crops they grow

How does extinction affect biodiversity?

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•The rate of extinction is increasing

•Scientists believe human activities have contributed to this

•20% of species alive today could be extinct by 2030

1/3 of the worlds primate species

What are 4 reasons to maintain biodiversity?

1. Interdependence of organisms
2. Genetic reasons
3. Economic reasons
4. Aesthetic reasons

What are keystone species?

when a species has a disproportionate effect on an ecosystem

Explain interdependence of species

Many ecosystems have evolved together and are highly interlinked and complex.

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If one species is affected by human activity this has a knock on effect.

Keystone species are an example of this, having a larger impact than other species

Explain genetic reasons for maintaining biodiversity

If biodiversity declines, genetic diversity will too.

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We can lose our solutions to our problems e.g. medicines, learning from plant species in response to disease

Explain economic reasons for maintaining biodiversity.

What do ecosystems help to do?

Scientists came up with a number that represents the value of natural ecosystems - $33x1012

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Ecosystems help to…

1\.Regulate climate

2\.Provide fresh water

3\.Fertile soil

4\.Recycle nutrients

5\.Detoxify waste

6\.Growth of materials like timber

7\.Molecules for medicine

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These all impact upon food production

How can monocultures cause soil depletion and why is this bad?

Soils that are subjected to constant monocultures become less fertile.

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Yield declines year on year. 

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The land becomes unusable

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More land is needed for agriculture 

Explain aesthetic reasons for maintaining biodiversity

Natural systems are important for well being, physical and mental health. 

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Reducing biodiversity exposes the soil and changes the landscape

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Flooding occurs more frequently

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Droughts are more common too