1.2 Systems & Models

Question 1

Gaia Theory Definition/Explanation

Answer 1

the Earth is a self-regulating complex system involving the biosphere, the atmosphere, hydrosphere and pedosphere

Question 2

“A systems approach” definition

Answer 2

A way of visualising a complex set of interactions which may be ecological or societal

Question 3

System Definition

Answer 3

An assemblage of parts and their relationships, forming a functioning entirety or whole. There are two major parts: Elements and Processes

Question 4

2 Parts of a System: Elements

Answer 4

Measurable things that can be linked together

ex. trees, shrubs, (items we can count, measure, weigh)

Question 5

2 Parts of a System: Processes

Answer 5

are the internal operations that transform inputs into outputs.They are dynamic and multifaceted, involving physical, chemical, or biological reactions.

Question 6

Emergent Properties definition

Answer 6

A property which a collection or a complex system has, but which the individual members do not have

Question 7

Emergent Properties example

Answer 7

Your lungs work and help you breathe due to all the cells in them functioning as a unit, but the cells themselves do not aid you breathing

Question 8

Flows in Systems, which 2?

Answer 8

Transfers, Transformations: represented by arrows

Question 9

Transfers

Answer 9

when a flow changes the location of something, without changing its form

It remains unchanged in state, e.g. water will flow into a lake and flow out of a lake; the lake being the store. It simply involves a change in location.

Question 10

Transformations

Answer 10

a flow involving a change of form/chemical nature within the system in the formation of a new end product

• matter to matter (glucose to starch)
• energy to energy (light to heat)
• matter to energy (respiration)
• energy to matter (photosynthesis)

Question 11

Open system definition

Answer 11

A system that exchanges both matter + energy with its surroundings (! All ecosystems/e.g. rainforest ecosystem)

Question 12

Open system process

Answer 12

Continuously exchange feedback with environments → analyse feedback → adjust internal systems as needed to achieve the goals → transmit necessary info back out to the environment

Question 13

Closed system definition

Answer 13

A system that exchanges only energy but not matter with its surroundings

e.x. The Earth, nitrogen cycle, carbon cycle

only exist experimentally, although global geochemical cycles approximate to closed systems

Question 14

Isolated System definition

Answer 14

A system that does not exchange neither matter or energy with its surroundings

e.x. the Universe

Question 15

Model Advantage

Answer 15

• easier to work w/ than complex reality
• can be used to predict the effect of a change of input
• can be applied to similar situations
• helps us see patterns
• visualise really small things (atoms)
• visualise really big things (solar system)

Question 16

Model Disadvantage

Answer 16

• accuracy is lost bc model is simplified
• if our assumptions/approximations are wrong, model will be wrong
• predictions may be inaccurate

Question 17

Model Definition

Answer 17

A simplified description used to understand how systems work, and to make predictions about what can happen in the future

i.e. physical model, software model, mathematic problems, data flow diagrams

Question 18

Transfers energy common example

Answer 18

ocean currents

Question 19

Transformations matter common example

Answer 19

evaporation

Question 20

Transformations energy common example

Answer 20

photosynthesis

Question 21

Transfers matter common example

Answer 21

herbivore eating plants

Question 22

Open system example +inputs/outputs

Answer 22

POND

outputs: matter=streamflow, energy= heat
inputs: matter=rainfall, energy=solar

Question 23

Closed system example + inputs/outputs

Answer 23

PLANET EARTH

outputs: energy=heat
inputs: energy=solar radiation

Question 24

When/Who Gaia Theory

Answer 24

1970s, British chemist James Lovelock