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Flashcards in Species Diversity Deck (15):

Define species diversity?

The number of different species and the number of individuals of each species in any one community.


Define species richness?

The number of different species in a particular area at a given time.


Define ecosystem diversity?

The range of different habitats within a particular area


Define habitat?

The place where things live, that provide a source of food and shelter.


Species diversity index?

d = -------------------
(The sum of) n(n-1)

d = species diversity index
N = total number of all organisms
n = total number of each species


What does species diversity index take into account?

How many different types of species there is and how often each species appears in the ecosystem.


A high species diversity index =

The greater the species diversity.


The impact of agriculture on biodiversity?

Farmers try to maximise the amount of food they can produce from a given area of land, but many methods used reduces biodiversity.


What things that farmers do reduce biodiversity?

- woodland clearance
- hedge grow removal
- pesticides
- herbicides
- monoculture


Why is woodland clearance and hedge grow removal done and how does it reduce biodiversity?

It's done to increase farmland, it directly reduces the number of trees and tree species. It also destroys habitats so some species may lose their shelter and food source causing them to die or migrate therefore Reducing biodiversity.


How do pesticides reduced biodiversity?

They are chemical that kill organisms, pests, that feed on crops. This reduces diversity directly by killing the pests, also any species that feed on the pest will lose their food source so reducing them too.


How do herbicides reduce biodiversity?

They are chemicals that kill unwanted plants so reducing the plant diversity and the number of organisms that use them as a food source.


How does monoculture reduce biodiversity?

Monoculture is when farmers have field which contain only one type of plant, this reduces the biodiversity directly and will support fewer organisms which also further reduces the biodiversity.


Conservation schemes?

Biodiversity helps to maintain the environment, it provides us with food source and medicines and it benefits agriculture. So there needs to be a balance between agriculture and biodiversity. Conservationists try to achieve this through conservation schemes.


Examples of conservation scheme?

- giving legal protection to endangered species.
- creating protected areas such as Areas of Outstanding Beauty which restricts further development.
- the Environmental Stewardship Scheme which encourages farmer to conserve biodiversity e.g. Replanting hedge grows, leaving margins around field for wild plant to grow and crop rotation.