1.2 - Systems And Models Flashcards
Define systems
an assemblage of parts and their relationship forming a functioning entirety or whole.
What are the 2 components to a system
Elements - measurable things that can be linked together. Example, trees, shrubs, herbs, birds and insects (items we can count, measure or weight
Processes - change elements from on form to another. These may also be called activities, relations, or functions. Example, growth, mortality, decomposition, and disturbances (what happens to the elements, or what the elements do)
Who came up with the GAIA hypothesis
James lovelock and Lynn margulis
What does the GAIA hypothesis say
That the world acts like a single biological being made up of many individual and interconnected units
What is a systems approach
A systems approach is a way of visualizing a complex set of interactions which may be ecological or societal. These interactions produce the emergent properties of the system
Why the system as a whole is greater than the sum of its parts
The interactions of the parts create something they could not produce independently
ex: two forest stands may contain the same tree species, but the spatial arrangement and size structure of the individual trees will create different habitats for wildlife species. In this case, an emergent property of each stand is the wildlife habitat
What are a holistic and emergent approach needed for when understanding the systems
A holistic approach is necessary to fully understand the way in which the parts of a complex system operates togher. An emergent property is a property which a collection or complex system has, but which the individual members do not have. A failure to realize that a property is emergent, or supervenient, leads to the fallacy of division.
How is there different scales to a system
There are different scales of systems. The range must include a small-scale local ecosystem, a large ecosystem such as a biome, and Gaia as an example of a global ecosystem. Forests contain many small-scale ecosystems
Compare reductionist and systems approaches to scientific research
Reductionist approach divers systems into parts or company’s which are studied separately. But a system can also be studied as a whole, with patterns, processes and interactions described for the whole system. This is more holistic, but much more complex, approach
Describe what its meant by the term “emergent prosperities”
Property which complex systems have but which the individual component do not have. Results from a system approach as the interactions between the components are what make up the emergent properties
Define storage
The stock of matter or energy within a system
Define flow
The movement of matter or energy from one storage to another, or into/out of the system
Define boundary
The designated area separating the system from its souroundings
Define input
Matter or energy entering the system
Define output
Matter or energy exiting the system
What are the 2 distinct types of flows depending on weather the matter/energy is changed or just moving
Transfer
Transformations
What’s a transfer
Occurs when energy or matter flows/moves and changes location but does not change its state or chemical composition eg. Rain falling into a lake, fall of leavers on ground
What’s a transformation
Occurs when energy or matter flows and changes its state or chemical composition
Eg. Light energy to stored/potential energy in photosynthesis
How do you draw a systems diagram
Arrows for inputs into a box and then out the other side arrows for outputs
How are systems categorised
Depending on weather or not energy and matter are able to enter/exit the system
What are the 3 systems
Open system
Closed system
Isolated system
Define open system in terms of energy and matter
Exchange energy and matter with their enviroments. They are organic (living) eg. Ecosystems/ people
Define closed systems in terms of energy and matter
Exchange energy but not matter with their environment. Examples are atoms, molecules and mechanical systems
Define isolated systems inot terms of energy and matter
Nether energy nor matter is exchanged with their environment. Do not enter naturally but an example could be the universe
State weather the following are open, closed or isolated systems
1. Natural forest ecosystem
2. A closed zip lock bag
3. A fish bowl
4. An adiabatic drinks flask
- Open
- Closed
- Open
- Isolated
Define the term model
A simplified version of a reality. Can be used to understand how systems work and predict how they will respond to change
How is a weather forecast tools considered models
Enviromental factors are very complicit with many interrelated components and it may be impossible to take all variables into account. Many assumptions need to be made. Relies on experts.
Why is a system diagram considered a model
They are simplified versions of a much more complex’s reality
What are some advantages of using models
Simplify a complex reality - they dont show too much information so it easy to follow and understand the components
Predicting future changes - inputs can be changed to examine the outputs without waiting for natural change
Identifying platterns - can be observed/run/manipulated several times under controlled conditions
Visualising small or large systems - can be used at a range of scales from biosphere to terrarium
What are some limitations of a model
Simplification vs accuracy - not all variables can be included so the interrelated factor are lost in some cases
Specialist knowledge - interpretation of the model depends on the expertise of the people making them for accuracy
Quality of input data - the more accurate and detailed the data and more reliable the model. Models can manipulated
Evaluate the model of a sheep farm system
Advantages -
- complex system simplified
- can predict changes
- can be applied to other systems
- major variables identified
Disadvantage -
- many missing variables
- size of inputs not shown
- size of outputs not shown
- does not consider variable nature of flows
- energy only shown as input
