1. Environmental Systems
Topic - 1 Systems and Models
Assessment Statements

2. So What is Environmental Systems About?
In this course we will be studying and analyzing the environment as a set of complex systems.
We won’t look at them separately as a biologist, geologist, or earth scientist would - but as all three professions combined.

3. So what is a system?
Systems are sets of entities that function as a whole; they can be isolated physically or conceptually.
A group of parts connected together in an organized way to make a more complex entity.

4. Examples of Systems

5. The System that we will study most….
The Ecosystem - a community of organisms in its abiotic environment, together with the relationships amongst these components.

6. Every system has a boundary
Outside of that boundary lies the system’s environment.
Environment: everything outside the system that can influence the system or in turn can be influenced by the system.

7. 3 Types of Systems
Open
Closed
Isolated

8. Almost all systems are open systems.
A type of system that exchanges matter and energy across its boundary with its environment.
Therefore, these systems exchange factors with other systems around them.
Almost all systems are open systems.

9. Diagram of an Open System

10. A system that exchanges energy with its environment but not matter.
Closed System
A system that exchanges energy with its environment but not matter.
Closed systems are not found in nature.
(But globally, the cycles of matter can be thought of as closed systems)
Ie:
How could you diagram a closed system?

11. The Earth is a system, but is it an open or closed one?

12. Isolated Systems
A System that exchanges neither matter nor energy with its environment.
This cannot exist.
Possible exception???
Students stand up and pair up. Student 1 – define Open; Student 2 – example Open
Student 2 – define Closed; Student 1 – example Closed
Student 1 – define Isolated; Student 2 – example Isolated

13. Every system consists of matter and energy …therefore are linked….How?
How Systems are Linked
Every system consists of matter and energy …therefore are linked….How?

14. The First Law of Thermodynamics
First Law - Energy may not be created or destroyed, but may change from one form to another.
AKA - The Law of Conservation of Energy
What does this mean?
Example?

15. Example: First Law of Thermodynamics
1. Energy from sun trapped by plants which convert it to glucose.
2. Herbivore eats plant and receives energy.
3. Carnivore eats herbivore and receives energy.
4. Energy released into atmosphere.
Example: First Law of Thermodynamics
The energy is changing forms and organisms, but is not being created or destroyed.

16. The Second Law of Thermodynamics
Second Law – “In any isolated system, entropy tends to increase spontaneously”
I.e.: Energy goes from a more useful form to a less useful as it is transferred between organisms.
After energy is released out into the environment, it is then not available to “do work”.
This brings about increasing disorder (i.e.: Entropy increases)
One more time…….Energy goes from a concentrated form and is dispersed out into the environment causing the system to become increasingly disordered.
Eventually, all energy is emitted back into the environment as heat, but it is NOT destroyed.
Example?

17. Ex. of Second Law of Thermodynamics
Since energy is released (lost) in the form of heat by the metabolism of organisms, there is less and less energy available to be used by consumers.
There must be a continual flow of energy into a system in order to keep a system going.
Ex. of Second Law of Thermodynamics
Stand up, pair up with someone new in area.
Describe one thing you understand about the Laws of Therm to each other.
Ask each other a question that you would like explained about the Laws.
Law of 10%

18. While energy is continuously flowing through systems….

19. ...matter tends to circulate around it.