Environmental Engineering Reference
In-Depth Information
ecosystem resilience, i.e. the ―propensity of ecological systems to suffer harm
from exposure to external stress and shocks‖ [19].
These terms (see following table) get crucial within this thesis since the
Resilience Alliance represents the main authority within resilience debate,
which necessitates not to ignore their terminology entirely. In the following
terms: engineering resilience and ecosystem resilience are used as the terms in
the definition of the resilience.[20]. Note that the term vulnerability is
important when one considers the concept of ecosystem resilience within the
framework of sustainability science.
Table 1. Terminology used by the Resilience Alliance
Stability term
Definition
Ecosystem resilience
Magnitude of disturbance that can be absorbed before the
system changes its structure by changing the variables and
processes that control behavior.
Engineering
resilience
Rate and speed of return to pre-existing conditions after
disturbance.
Both resilience definitions refer to the term disturbance. Disturbance
represents important and widespread phenomena in nature which is considered
as an ecologically significant object for study in itself [21].
Ecosystems cannot be seen as static entities, rather, they represent alway s
changing, fluctuating, dynamic systems .There is no balance of nature, rather
endless change and the ongoing creation of novelty are the rule [22]. The
definition includes environmental fluctuations and destructive events, whether
or not these are perceived as ―normal‖ for a particular system. However, a
distinction between natural small-scale disturbances and human large-scale
disturbances tries to delimit disturbances that are considered to be part of the
system from others that are superimposed on the system. This distinction gets
important when relatively small disturbances are conceived as being an
integral part of the ecosystem dynamics. Small-scale disturbances as integral
parts of ecosystems are fundamental for the generation of ecosystem
resilience.
From a system perspective several descriptors of disturbances can be
considered that together constitute the disturbance regime: spatial distribution
of the disturbance relative to environmental or community gradients,
