TOPIC 4C 1 BIODIVERSITY AND ENDEMISM

What is biodiversity?

1. It is a measure of the variety of living organisms and their genetic differences.

2. The differences between individuals in a species, between populations of the same species, between communities and between ecosystems.

3. Biodiversity can be assessed on different scales.

Why is biodiversity important?

1. All organisms in an ecosystem are interdependent.

2. Rich biodiversity allows large scale ecosystems to function and self-regulate.

3. Ecosystems are interlinked all across the world.

Give an example on the imporatance of biodiversity.

1. Land plants absorb more than A-Third of all the carbon dioxide that are produced by burning fossil fuels. PLANTS ABSOD VAST AMOUNTS OF WATER FROM SOIL, WHICH THEN EVAPORATES BACK TO THE AIR VIA TRANSPIRATION.

2. This produces clouds, which reduce rain, hence plants determine where ran fall.

3. Which then determines what organisms can survive and get water.

What are the two ways to measure biodiversity at the species level?

1. Assessing species richness.

2. Assessing species abundance.

What is species richness?

1. It is the number of different species in an area.

What is relative species abundance?

1. It is the evenness of distributions of the different species.

What is endemic?

1. It is a species that evolves in geographical isolation and is found in only one place.

Give some examples of endemic species.

1. Marsupials Like kangaroos and koalas.

2. Red slender loris of Sri Lanka.

What should be noted about the biodiversity of paces with most endemic speacies?

1. Areas with greatest biodiversity are not always the same as areas with the greatest number of endemic species.

What are some theories that some places are biodiversity hotspots?

1. A very stable ecosystem allows many complex relationships to develop between species.

2. High levels of productivity (high photosynthesis rate) can support more niches.

3. When organisms a grow and reproduce rapidly, it is more likely that mutations occur, leading to adaptations which allow organisms to exploit more niches.

Which area has more biodiversity? An area showing an even abundance of different species or an area containing the same number of species but dominated by one or two of those species.

1. The area showing an even abundance of different species.