8 Ecology and Applied Environmental Science
1.4 thE EcoSyStEM aS a SyStEM
The ecosystem is a complex concept, the understanding and treatment of
which are of particular interest but also present many difficulties. It is obvious that the ecosystem has the property of constituting a unit and at the same
time a set of elements. Its elements are connected in a variety of ways, via
dependences and interactions. Their close correlation forms a unit with its
own characteristics, which does not allow the behaviour of the ecosystem to
be reduced to a mere sum of the properties of its parts. Thus the ecosystem
is an instance where the theoretical concept of the system can be successfully
applied to reality.
The action of external factors becomes perceptible by means of one or
more of its components, but it affects the ecosystem, to a greater or lesser
degree, as a unified whole. By causing actions and chain reactions, it disturbs
the ecosystem, causing it to depart for a time from a state of equilibrium, or
propelling it to a new equilibrium, or, in extreme cases, driving it to collapse.
Ecosystems are extremely complex systems, with a great number of internal
and external interactions. Usually just the trophic relationships among the various organisms of an ecosystem form a complex web of internal links. Human
beings are one of the numerous interacting elements of ecosystems. They
have acquired the ability to bring about great changes in ecosystems, but not
to exercise effective control. Thus they are often unable to manage them successfully and protect them from the undesirable side effects of their activities.
A natural ecosystem is generally maintained in a state of dynamic equilibrium, where various processes of control, regulation, and feedback play a
fundamental part. In parallel, if the ecosystem has not yet reached its most
mature form, it evolves at a slow pace, through successive states of equilibrium, where the phenomenon of ecological succession may be observed.
The stability of an ecosystem is dependent on the constant, regular flow
of energy and circulation of vital chemical substances through its structures. Due to its organisation, when the ecosystem moves away from the
state of equilibrium without escaping from certain bounds, internal changes
are generated which return it to the state of equilibrium. In certain cases,
the ecosystem has this ability (resilience) even for very great disturbances.
The maintenance of states of equilibrium becomes apparent when the
long-term persistence of ecosystems is observed, and it constitutes the objective of managing or protecting them from human disturbances. Thus the
property that in general serves the sought-for conservation of eco systems is
the stability of equilibrium states.
An examination of the natural environment using the concept of the ecosystem is fruitful in many applications and meets scientific needs, such as:
• Understanding the functioning of parts of the environment and/or the
whole biosphere
1.4 thE EcoSyStEM aS a SyStEM
The ecosystem is a complex concept, the understanding and treatment of
which are of particular interest but also present many difficulties. It is obvious that the ecosystem has the property of constituting a unit and at the same
time a set of elements. Its elements are connected in a variety of ways, via
dependences and interactions. Their close correlation forms a unit with its
own characteristics, which does not allow the behaviour of the ecosystem to
be reduced to a mere sum of the properties of its parts. Thus the ecosystem
is an instance where the theoretical concept of the system can be successfully
applied to reality.
The action of external factors becomes perceptible by means of one or
more of its components, but it affects the ecosystem, to a greater or lesser
degree, as a unified whole. By causing actions and chain reactions, it disturbs
the ecosystem, causing it to depart for a time from a state of equilibrium, or
propelling it to a new equilibrium, or, in extreme cases, driving it to collapse.
Ecosystems are extremely complex systems, with a great number of internal
and external interactions. Usually just the trophic relationships among the various organisms of an ecosystem form a complex web of internal links. Human
beings are one of the numerous interacting elements of ecosystems. They
have acquired the ability to bring about great changes in ecosystems, but not
to exercise effective control. Thus they are often unable to manage them successfully and protect them from the undesirable side effects of their activities.
A natural ecosystem is generally maintained in a state of dynamic equilibrium, where various processes of control, regulation, and feedback play a
fundamental part. In parallel, if the ecosystem has not yet reached its most
mature form, it evolves at a slow pace, through successive states of equilibrium, where the phenomenon of ecological succession may be observed.
The stability of an ecosystem is dependent on the constant, regular flow
of energy and circulation of vital chemical substances through its structures. Due to its organisation, when the ecosystem moves away from the
state of equilibrium without escaping from certain bounds, internal changes
are generated which return it to the state of equilibrium. In certain cases,
the ecosystem has this ability (resilience) even for very great disturbances.
The maintenance of states of equilibrium becomes apparent when the
long-term persistence of ecosystems is observed, and it constitutes the objective of managing or protecting them from human disturbances. Thus the
property that in general serves the sought-for conservation of eco systems is
the stability of equilibrium states.
An examination of the natural environment using the concept of the ecosystem is fruitful in many applications and meets scientific needs, such as:
• Understanding the functioning of parts of the environment and/or the
whole biosphere