Post on 17-Jan-2018
description
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?