THEME 1: THE ENVIRONMENT AS A SYSTEM
The natural environment is not a static given entity, but a living functioning
and highly complex unit consisting of many functionally interrelated elements.
A change to any part thereof must therefore influence the system as a whole.
A holistic approach to the study of the environment is therefore necessary
(Hugo & Viljoen, 1992).
1.1 THE SYSTEM AS RESEARCH MODEL
In order to utilize the environment fully a thorough knowledge of its functioning
is required. However, the immense complexity of nature necessitates its
conceptual simplification. Only once the underlying components have been
studied in isolation can one hope to digest its underlying dynamical
interactions. A system-approach is followed in order to form a global picture
of this entire dynamic-functioning interrelationship in nature.
Cooks (1990) describes this approach as follows:
Depending on the purpose of the study, one can choose to follow various
kinds of approaches when attempting to solve problems. Sometimes it is
sufficient to consider a system as a unit without considering its internal
structure and functioning. The emphasis in such an approach is placed on the
outputs, which are the result of the identified inputs. Such an approach is
termed a black box. It can thus be defined as any unit of which the function
can be evaluated without specifying the contents thereof (Figure 1.1 top).
1
, Figure 1.1 Various levels of complexity in system modelling (after Hugo & Viljoen,
1992).
With an increase in the level of discrimination, the black box can progressively
be divided into sub-compartments, each of which will form a black box. We
will then be able to observe certain relationships and structures between the
compartments although the internal structure of each sub-compartment
remains unknown. The composite of these smaller sub-compartments
provides us with partial knowledge of the internal structure, relationships and
processes of the system and is referred to as a grey box (Figure 1.1 middle).
We eventually refer to a white box when the division of components has
progressed to the point where most of the elements, relationships and
processes within the system are known (Figure 1.1 bottom). There will,
however, always remain black box elements within a natural environment
system since the environment is so complex that it is impossible to break it
down to its finest details, and since no model can be a complete
representation of the reality.
2
The natural environment is not a static given entity, but a living functioning
and highly complex unit consisting of many functionally interrelated elements.
A change to any part thereof must therefore influence the system as a whole.
A holistic approach to the study of the environment is therefore necessary
(Hugo & Viljoen, 1992).
1.1 THE SYSTEM AS RESEARCH MODEL
In order to utilize the environment fully a thorough knowledge of its functioning
is required. However, the immense complexity of nature necessitates its
conceptual simplification. Only once the underlying components have been
studied in isolation can one hope to digest its underlying dynamical
interactions. A system-approach is followed in order to form a global picture
of this entire dynamic-functioning interrelationship in nature.
Cooks (1990) describes this approach as follows:
Depending on the purpose of the study, one can choose to follow various
kinds of approaches when attempting to solve problems. Sometimes it is
sufficient to consider a system as a unit without considering its internal
structure and functioning. The emphasis in such an approach is placed on the
outputs, which are the result of the identified inputs. Such an approach is
termed a black box. It can thus be defined as any unit of which the function
can be evaluated without specifying the contents thereof (Figure 1.1 top).
1
, Figure 1.1 Various levels of complexity in system modelling (after Hugo & Viljoen,
1992).
With an increase in the level of discrimination, the black box can progressively
be divided into sub-compartments, each of which will form a black box. We
will then be able to observe certain relationships and structures between the
compartments although the internal structure of each sub-compartment
remains unknown. The composite of these smaller sub-compartments
provides us with partial knowledge of the internal structure, relationships and
processes of the system and is referred to as a grey box (Figure 1.1 middle).
We eventually refer to a white box when the division of components has
progressed to the point where most of the elements, relationships and
processes within the system are known (Figure 1.1 bottom). There will,
however, always remain black box elements within a natural environment
system since the environment is so complex that it is impossible to break it
down to its finest details, and since no model can be a complete
representation of the reality.
2
