Natural Systems

3.1.1.1

What is a flow / transfer?

A form of linkage between one store / component and another that involves movement of energy or mass.

What is an input?

The addition of matter and/or energy into a system.

What is a store / component?

A part of the system where energy/mass is stored or transformed.

What is a system?

A set of interrelated components working together towards some kind of process.

They have a series of stores or components that have flows or connections between them.

For example, the ARF.

What is an output?

Matter or element leaving the system.

What are boundaries?

The limits of the system.

What occurs when inputs and outputs are balanced?

Equilibrium - inputs and outputs vary at times.

What occurs when inputs and outputs are out of balance for a long time?

Positive or negative feedback loops are established to cause a system to change.

What are the three types of property that make up a system?

Elements, attributes and relationships.

What are the elements (of a system)?

The components that make up the system of interest.

So, the measurable physical objects or entities present in the geographical landscape.

For example, the elements of the ARF are the tropical trees and the atmosphere.

What are the attributes (of a system)?

The perceived characteristics of the elements.

The distinct traits, quantities, or qualities that describe the individual elements.

For example, the attributes of the ARF are the high biomass volume of the trees (storing lots of carbon)and high humidity of atmosphere.

What are the relationships (of a system)?

Descriptions of of how the various elements and their attributes work together to carry out some kind of process.

For example, the relationships in the ARF are how trees absorb carbon dioxide from the atmosphere, linking trees and atmosphere together.

What are the three types of system?

Isolated, closed and open systems.

What is an isolated system?

These have no interactions with anything outside the system boundary. There’s no input or output of energy or matter.

What is a closed system?

They have transfers of energy into and beyond the system boundary but not transfer of matter.

What is an open system?

Where matter and energy can be transferred from the system across the boundary into the surrounding environment.

What is positive feedback?

Where the effects of an action are amplified or multiplied by subsequent knock-on or secondary effects.

Moves system further away from its equilibrium making it unstable.

Produces effect typically seen as negative.

What is negative feedback?

Where the effects of an action are nullified by its subsequent knock-on effects.

Reduces or reverses the effect of initial disturbance.

Produces effect typically seen as positive.