1. Topic 1
Systems and Models

2. Assessment Statements
1.1 Outline the concepts and characteristics of a system
1.2 Apply the systems concept on a range of scales
1.3 Define the terms open, closed, and isolated systems
1.4 Describe how the 1st and 2nd laws of thermodynamics are relevant to environmental systems

3. Assessment Statements Continued
1.5 Explain the nature of equilibria
1.6 Define and explain the principles of positive and negative feedback
1.7 Describe transfer and transformation processes
1.8 Distinguish between flows (inputs and outputs) and storages (stock) in relation to systems

4. Assessment Statements Continued
1.9 Construct and analyze quantitative models involving flows and storages in a system
1.10 Evaluate the strength and limitations of models

5. 1.1 Outline the concepts and characteristics of a system
System – assemblage of parts and the relationships between them, which constitute an entity or whole.
The whole is greater than the sum of the parts.

6. 1.1 Outline the concepts and characteristics of a system
Systems consist of:
Storage
Flows
Processes
Feedback mechanisms that maintain stability and equilibrium
Example: Human

7. 1.2 Apply the systems concept on a range of scales
Works for everything from a single celled organism to our planet and beyond

8. 1.3 Define the terms open, closed, and isolated systems
Open System
Example: Living organisms
Closed System
Example: Water or Nitrogen Cycle
Isolated System
Example: The Universe maybe
Matter
Exchanged across boundaries
Not exchanged across boundaries
Energy

9. 1.4 Describe how the 1st and 2nd laws of thermodynamics are relevant to environmental systems
1st Law = Energy is neither created or destroyed.
In nature energy comes in as sunlight, passes along as biomass, and exits as heat bit by bit.

10. 1.4 Describe how the 1st and 2nd laws of thermodynamics are relevant to environmental systems
2nd Law = Energy goes from a concentrated form into a dispersed form. Available energy decreases with time as order takes energy.
In nature as energy is transformed, some of it is lost as heat. Only continues due to constant input of sunlight.

11. 1.5 Explain the nature of equilibria
Steady-state equilibrium – Maintains a stable system due to constant flow of inputs and outputs
Static doesn’t apply to natural systems as there are no inputs or outputs so no change occurs.
Refers to state of balance
Static – always in balance
Inanimate objects
Stable – Returns to balance after disturbance
Rubber
Unstable – Achieves new balance after disturbance
Car Crash

12. 1.6 Define and explain the principles of positive and negative feedback
Negative Feedback – dampens effects and promotes return to stability
Predator-prey relationships
Positive Feedback – Amplifies change and leads to deviation from stability
Temperature and greenhouse gases

13. 1.7 Describe transfer and transformation processes
Transfer – Flows through the system and changes location
Transformation – Interaction within a system in the formation of a new end product, or a change in state

14. 1.8 Distinguish between flows (inputs and outputs) and storages (stock) in relation to systems
Flows – inputs and outputs for systems represented by arrows
Storage – stock held within a system represented by boxes

15. 1.9 Construct and analyze quantitative models involving flows and storages in a system
Model – Simplified description designed to show the structure or workings of an object, system or concept.
This is why we are doing the systems poster. We will add storages to it, and it will meet this assessment statement.

16. 1.10 Evaluate the strength and limitations of models
Advantages
Disadvantages
Can predict and simplify complex systems
Inputs can be changed and outputs examined without waiting for real events
Results can be shown to others
May not be accurate
Rely on the expertise of those making it
Different people may interpret them in different ways
Vested interests may hijack them politically
Only as good as the data that goes in
Different models may show different effects with same data

17. 3.2.4 Discuss the view that the environment can have its own intrinsic value.
Intrinsic value – Value in it’s own right, irrespective of economic value
Non-consumptive use – Recreational and cultural activities that do not require harvesting of products.

18. 3.2.4 Discuss the view that the environment can have its own intrinsic value.
Indirect use values– derived from ecosystem services that provide benefits outside of the ecosystem itself.
Natural water filtration
Optional value – derived from potential future use of ecosystem goods and services not currently being used.

19. 3.2.4 Discuss the view that the environment can have its own intrinsic value.
Non-use (existence) values – Aesthetic and intrinsic values
Other ways to measure value of a resource include calculating or estimating:
Cost of replacing it with something else
Cost of mitigating its loss
Cost of averting the cost of its degradation
Its contribution to other income or production
How much people are prepared to pay for it