Notes

What are systems?
A systems approach is a way of visualizing a complex set of interactions,which can be applied across a wide range of different disciplines. The advantage of using thesystems method is that it can show how components within the whole system relate toone another. This course focuses on systems as they relate to ecosystems and society, although the systems approach can equally be applied to other subjects such as economics or politics.
The systems concept on a range of scales
An ecosystem is a community of organisms and the physical environment they inhabit. Anecosystems can be viewed on the localscale (i.e. within one country) or more widely (in many different countries where the same climatic conditions apply). On the global scale, ecosystems with similar climaticconditions in different parts of the world are called biomes.

The characteristics of systems
A system consists of storages and flows. Storages are places where matter or energy
is kept in a system, and flows provide inputs and outputs of energy and matter.
The flows are processes that may be either transfers (a change in location) or
transformations (a change in the chemical nature, a change in state or a change in
energy).A diagram can show several storages and the flows between them, and show the
relationship between the parts of a complex system. For example, Figure 1.8 shows a
systems diagram for the movement of energy and matter in a forest ecosystem.
Boxes in Figure 1.8 show storages, such the atmosphere and biomass (i.e. biological
matter). Arrows show flows – inputs to and outputs from storages. The arrows are
labelled with different processes, either transfers or transformations.

Open systems are organic (i.e. living) systems that interact with their environment to take in energy and new matter, and to remove wastes (e.g. an ecosystem) People are also open systems in that they must interact with the environment in order to obtain food, water, shelter, and shelter from the elements, and produce wasteproducts.