What do the following species have in common?

Let’s visualise a pond dip

Explain the terms biodiversity and endemism and describe how biodiversity can be measured within a habitat using species richness and within a species using genetic diversity, eg variety of alleles in a gene pool.

Biodiversity appears to be a buzz word but do you know what it actually means?

Biodiversity comprises of every form of life, from the smallest microbe to the largest animal, the genes that give them there specific characteristics and the ecosystems they are part. This includes diversity within species, between species and of ecosystems.

The Convention on Biological Diversity

In a pond dip

Although the number of different species is a useful basic measure, the concept is much more.

Differences between

•Individuals of a species

•Between populations of the same organism

•Communities

•Between ecosystems.

Why is it so important?

You should know already that all organisms in an ecosystem are interlinked. But what is not as obvious is that all ecosystems are interlinked on a larger scale across the earth.

Look at transpiration

Are some species more important than others?

Normally you think about important species such as …….

However, those further down the food chain are more important

Eg. the simple

Jungle burger

Fig wasp

Key Stone Species

Plays a major role in the survival of kelp forests

Caledonian Forest

Scots Pine

Are some places more important than others?

www.biodiversityhotspots.org Many papers published

Are some places more important than others?

Fact!

In an area of the Amazon Rainforest of a size less that of 4 tennis courts there are ………… different species of tree found.

In temperate rainforests there is between …………

In Boreal rainforests there is ……………..

Norman Myers identified a number of Biodiversity Hotspots.

A picture for the ladies!

Unfortunately the areas correspond with areas where people live

Measuring Biodiversity

Species Richness

The number of species in a given habitat

Salmon

Lizards

Species Evenness

Species Evenness

Species Wood A Wood B Wood C

Blue Tit 25 20 50Robin 20 17 12Wren 11 23 3Blackbird 9 22 27Willow Warbler 17 0 0Green Tit 7 18 8Blackcap 4 0 0Song Thrush 7 0 0

Can you compare woodlands A, B and C and comment on their diversity.

A diverse community will have high species richness and high evenness .

Managed Natural

Oak 50 15

Ash 10 15

Sycamore 25 0

Field Maple 2 15

Hazel 3 20

Small Leaved Lime 0 8

Wild Service 0 9

Common Hawthorn 5 0

Midland Hawthorn 0 10

Holly 2 8

Beech 3 0

Total 100 100

Simpson's Diversity IndexA community dominated by one or two species is considered to be less diverse than one in which several different species have a similar abundance.

Simpson's Diversity Index is a measure of diversity which takes into account the number of species present, as well as the relative abundance of each species. As species richness and evenness increase, so diversity increases.

n = the total number of organisms of a particular speciesN = the total number of organisms of all species The value of D ranges between 0 and 1. With this index, 1 represents infinite diversity and 0, no diversity.

n = the total number of organisms of a particular speciesN = the total number of organisms of all species

Problems

Not constant

Time of day (nocturnal)

Time of year

Migration

Techniques

Some Questions

1. The term biodiversity is often used in the media simply as the number of species of living organisms. Explain why this gives a limited picture?

2. Draw a flow chart to show the impact of sea otters on kelp forests and explain why they are regarded as key stone species.

3. Explain how high biological productivity and rapid mutation rates can explain how areas of high biodiversity such as tropical rainforests come about.

4. Explain how areas of high bird diversity and high bird endemism come differ and why this might be.