1. Starter
What changes do you think will happen to the following areas within an ecosystem during succession?
Size of organisms
Energy flow
Soil
Biodiversity
NPP and GPP

2. Changes in succession You should all be able to:
Identify changes in energy flow, gross and net productivity, diversity and mineral cycling at different stages of succession.
Identify different types of climax community
Most of you should be able to:
Explain why these changes are happening.

3. Complete the table
As we go through the different factors complete the table with the changes that happen during succession.
Start now by filling in the “types of vegetation” section in your groups.

4. Productivity
Describe what is happening in this graph…

5. Productivity
During early stages gross productivity is because of initial conditions and low density of producers.
The proportion of energy lost through respiration is relatively
So net productivity is
In middle stages gross productivity may be
In later stages, GPP as climax community reaches maturity
Respiration rates are so net productivity is

6. Productivity Early Stage Middle Stage Late Stage Low GPP
NPP is a high percentage of GPP – low respiration
Little increase in biomass
Gross Productivity high– increased photosynthesis
Increases in biomass as plant forms become bigger
Trees reach their maximum size
Ratio of GPP to R is roughly equal
NPP low
What’s GPP and NPP?

7. Gross Primary Productivity is low but Net Primary Productivity is a large proportion of GPP because little biomass means respiration is low.
NPP as a percentage of GPP falls because respiration rates increase with more biomass

8. Biodiversity
What do you think will happen to biodiversity as succession occurs? Why?

9. Mineral cycling
Through the process of succession the level of nutrients within the community increases. Most of these nutrients are held within the vegetation.
At the beginning of succession there are fewer nutrients within the community. Most of these nutrients are held within the soil.

10. Now complete any missing sections in your table…

11. Disturbance
In pairs try to think of possible disturbances that could cause these set backs…

12. Checking outcomes
Cut out the pictures and stick them down to create a diagram showing the process of succession.
Identify the different stages of succession and label your diagram
Annotate how each of the following aspects change through succession:
Size of organisms
Energy flow
Gross and net productivity
Biodiversity
Mineral cycling / soil
Now add an explanation for why each of these aspects changes through succession.