4 Ecology and Applied Environmental Science
The concept of system contributes to a theoretical approach to the
organization of the differences observed in various description levels of
the world, such as physicochemical, biological, psychological, and social.
The laws of each lower level, e.g. of physics and chemistry, apply and are
totally compatible with the phenomena of the higher levels of description
but do not contain all the concepts necessary for an understanding of these
phenomena. The extensive use of systems in biology, in ecology, and in
the social sciences is due to the complexity of the relevant phenomena.
This consideration stresses the organisation of the subject rather than its
material structure. Some of the characteristic issues it examines are organisation, differentiation, rank, information, communication, and control.
The study of problems on the basis of the relationship between the interaction of the parts and the whole is defined as a systemic approach.
1.2 concEPt and uSE oF ModElS
The model can be defined as a simplified representation of reality. This broad
definition includes many material and intellectual objects: for example,
every word or every mental image is a model. In the exact sciences the model
is used as a basic tool for reconstructing nature in order to study it. In this
sense it is a hypothetical system that is realistic enough to meet the objective
of study.
The use of models in science has two different aims: to explain and to
forecast phenomena. Two types of models correspond to these aims:
Figure 1.1 Four-part system. (From Hadjibiros, K. (2007). Ecology. Ecosystems and
Environmental Protection, 3rd edition. Symmetria, Athens (in Greek).
With permission.)
The concept of system contributes to a theoretical approach to the
organization of the differences observed in various description levels of
the world, such as physicochemical, biological, psychological, and social.
The laws of each lower level, e.g. of physics and chemistry, apply and are
totally compatible with the phenomena of the higher levels of description
but do not contain all the concepts necessary for an understanding of these
phenomena. The extensive use of systems in biology, in ecology, and in
the social sciences is due to the complexity of the relevant phenomena.
This consideration stresses the organisation of the subject rather than its
material structure. Some of the characteristic issues it examines are organisation, differentiation, rank, information, communication, and control.
The study of problems on the basis of the relationship between the interaction of the parts and the whole is defined as a systemic approach.
1.2 concEPt and uSE oF ModElS
The model can be defined as a simplified representation of reality. This broad
definition includes many material and intellectual objects: for example,
every word or every mental image is a model. In the exact sciences the model
is used as a basic tool for reconstructing nature in order to study it. In this
sense it is a hypothetical system that is realistic enough to meet the objective
of study.
The use of models in science has two different aims: to explain and to
forecast phenomena. Two types of models correspond to these aims:
Figure 1.1 Four-part system. (From Hadjibiros, K. (2007). Ecology. Ecosystems and
Environmental Protection, 3rd edition. Symmetria, Athens (in Greek).
With permission.)