Starter

Trophic Level Productivity (units?)

Producers 5000

Primary consumers 500

Secondary consumers 50

Tertiary consumers 5

1. Using the data provided, draw a pyramid of productivity.2. What are the units for productivity? – include them3. What does productivity represent in organisms?4. How much energy passes from one trophic level to the next?

Learning outcomes

You should all be able to:• Define gross productivity, net productivity, primary

productivity and secondary productivity

Most of you should be able to:• Calculate the values of gross and net productivity from

given data

What is productivity?

Thinking about ecosystems – how do you think we measure productivity?

There are two types of productivity

Primary Secondary

What do you think the difference is?

Discuss it with a partner now write down your idea on the sheet

Primary Productivity - plants• Conversion of solar energy

Carbon dioxide from the atmosphere

Water from the soil

Oxygen released

Sunlight

What factors affect primary productivity?

• Amount of sunlight• Availability of factors needed for growth• Levels of insolation• Supply of water• Temperature• Nutrient levels• Efficiency of producers

Secondary Productivity - animals

These two types can be divided…

Gross productivity Net productivity

What do you think the difference is?

• Gross productivity is the total gain in energy or biomass per unit area per unit time

• Net productivity is the remaining energy that is available to the next trophic level.

GPP and NPP

What can you see happening in the diagram?

How would you calculate GPP and NPP?

GSP and NSP

GROUP ACTIVITY

pyramid of productivity

Starter

1. What does NPP stand for?

2. What does it mean?

3. How would you calculate it?

4. What about GSP?

pyramid of productivity

NPP - Low

Arctic Tundra Sonoran Desert

NPP - High

Tropical Rainforest

Checking outcomes

What is net productivity and gross productivity?

What is primary and secondary productivity?

How can you calculate NPP?

How can you calculate GSP?