1.2 Systems & Models Flashcards
When/Who Gaia Theory
1970s, British chemist James Lovelock
Gaia Theory Definition/Explanation
the Earth is a self-regulating complex system involving the biosphere, the atmosphere, hydrosphere and pedosphere
“A systems approach” definition
A way of visualising a complex set of interactions which may be ecological or societal
System Definition
An assemblage of parts and their relationships, forming a functioning entirety or whole. There are two major parts: Elements and Processes
2 Parts of a System: Elements
Measurable things that can be linked together
ex. trees, shrubs, (items we can count, measure, weigh)
2 Parts of a System: Processes
are the internal operations that transform inputs into outputs.They are dynamic and multifaceted, involving physical, chemical, or biological reactions.
Emergent Properties definition
A property which a collection or a complex system has, but which the individual members do not have
Emergent Properties example
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
Flows in Systems, which 2?
Transfers, Transformations: represented by arrows
Transfers
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.
Transformations
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)
Open system definition
A system that exchanges both matter + energy with its surroundings (! All ecosystems/e.g. rainforest ecosystem)
Open system process
Continuously exchange feedback with environments → analyse feedback → adjust internal systems as needed to achieve the goals → transmit necessary info back out to the environment
Closed system definition
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
Isolated System definition
A system that does not exchange neither matter or energy with its surroundings
e.x. the Universe
