Topic 4.6 Biodiversity Flashcards
(12 cards)
What is biodiversity?
The number and variety of living things found in the world, an ecosystem or a habitat
How can biodiversity be considered?
Species diversity
Genetic diversity
Habitat diversity
What is species diversity?
The number of individuals of each species in a community
What is species richness?
The number of different species in a community
What is ecosystem diversity?
The range of different habitats from small local habitats to the whole of the planet
How is biodiversity measured?
Index of diversity:
N(N-1) divided by the sum of n(n-1)
where
N: total of all individuals
n: number of individuals of a particular species
What does a high diversity index show?
A diverse habitat
Why is a high diversity index good?
The habitat is stable and able to withstand change.
An environmental change that affects 1 species will have a small impact on the community
What does a low diversity index show?
The habitat is dominated by a few species
Why is a low diversity index not good?
An environmental change affecting one of these major species may have a large impact on the community
The community may be vulnerable to damage by introduced species, new diseases or human activity
What are the 5 reasons agriculture decreases biodiversity?
- Removal of hedgerows
- Monocultures
- Filling ponds and draining marshes/wetland
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