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In-Depth Information
in the future (Friedel 1991, Agnew 1997)? Do 'early
warning' or 'immune systems' exist in ecosystems
(Levin 2001)? Can a 'healthy' system invent and
experiment (Holling 2001) in an ongoing context
of self-organization within a 'panarchy'; that is, a
nested hierarchical set of adaptive cycles (Gunderson
& Holling 2002)? The reader interested in resilience,
self-organization and related topics should be aware
of the highly influential model of adaptive cycles
introduced by C.S. Holling (1973) and developed in
numerous arenas by the internet-based Resilience
Alliance which publishes the online journal
Ecology
and Society
(www.ecologyandsociety.org; formerly
Conservation Ecology
).
These questions are all clearly fundamental to the
conceptual advancement of the science and the prac-
tice of restoration, especially if the motivation is the
broad reason 3, above; all the natural goods and ser-
vices flowing from natural capital. At the heart of these
issues is the notion of resilience (see also Chapter 2),
which of course is a term originating in physics, where
it is used to describe the degree of mechanical resist-
ance of a material subjected to an impact. A notable
cross-disciplinary interest in this notion exists today,
which underlines the fact that resilience is an excel-
lent vehicle or focal point for the study of systems at
many nested levels of complexity, and at various
spatial scales. For example, the term resilience is much
discussed in psychology and psychiatry today, refer-
ring to the capacity of a child or adult to return to a
healthy or normal life despite experiencing a serious
wound or stress, or the capacity to continue learning
and growing even in environments or situations that
should be debilitating (Cyrulnik 2001). Notably,
Walker
et al.
(2002), of the Resilience Alliance, have
recently redefined resilience as 'the degree to which
an ecosystem expresses capacity for learning and
adaptation'. This definition is highly reminiscent of the
terms used by the psychiatrist Cyrulnik mentioned
just above. Although the rapprochement should be
made with caution, it does seem increasingly clear that
the sciences of human health on the one hand, and
of ecosystem health on the other, have much to give
one another. To become truly scientific, however, the
study of ecosystem health, like that of ecosystem
resilience, must move steadily beyond the realm of
metaphor to that of measurement (Carpenter
et al.
2001).
16.2.5 Ecosystem health and integrity
Health does not equal integrity, but the two are inter-
related. The SER Primer (SER 2002) distinguishes
between these terms by defining
integrity
in terms of
biodiversity - particularly species composition and com-
munity structure - whereas
health
is defined as an
ecosystem's overall dynamic state at a given time based
on ecosystem functioning. Indeed, Ulanowicz (1997)
and Mageau
et al.
(1995) argue that ecosystem health
is something to be measured at a given point in time,
while integrity can only be evaluated over a longer
period. Kay and Regier (2000) argue that ecological
integrity is 'about maintaining the integrity of the pro-
cess of [and the capacity for] self-organisation', over
time and under a variety of environmental conditions
or contexts. A major research goal is to refine these
concepts and methods of analysis and measurement
(Costanza
et al.
1992, Wu & Loucks 1995, Rapport
et
al.
1998, Ernest & Brown 2001, Müller 2003; see also
Chapter 2). A major challenge today is to experiment-
ally and practically apply both concepts - health and
integrity - to natural and socio-ecological systems at
both regional and global scales (Crabbé
et al.
2000).
A relevant point can be made here about health,
and it is one that may help in communication between
scientists and non-scientists, and among biologists,
social scientists, physicians and psychologists. Health
for humans can be defined as the absence of known
diseases, parasites, etc., and a general sense of well-
being. Of course, ecologists cannot readily use the
notion of 'a
sense
of well-being' when considering
the health of ecosystems (but see Kay & Regier 2000,
pp. 133-4). Yet, as we have shown already, an essen-
tial element of both human and ecosystem health is
resilience or adaptive capacity. From this it follows
that reason 3 of why to restore, above, is by far the
most important, since by focusing on protecting,
managing and, where necessary, restoring natural
capital, we have the best chance of maintaining
long-term, intergenerational resilience and overall
health of life-supporting ecosystems. In this light, the
notion of ecosystem or natural capital should be
understood as referring not only to economic goods
and services (reason 2), and not only to biodiversity
(reason 1), but also to health, both of life-supporting
ecosystems and of all living creatures, including
