Geoscience Reference
In-Depth Information
2.2.1 From stability to complexity
For much of the twentieth century, ecosystems were understood to be
entities that tend towards a single equilibrium state and whose patterns
of development, in theory at least, could be predicted. Tansley, who in
1935 proposed the ecosystem concept to de
ne biological assemblages
interacting with their physical and climatic environments, viewed the
components of ecosystems as being in a relatively stable dynamic equili-
brium which would progress towards the formation of climax communi-
ties representing the nearest approach to perfect dynamic equilibrium that
the system could attain.
3
His belief, and that of the ecologists who followed
him, in ecological development as predictable, unidirectional and culmi-
nating in a maximal state engendered con
dence that, through mathema-
tical modelling, ecosystem behaviour could be understood, predicted and
manipulated to humanity
t.
4
Eugene Odum, in his work of the 1960s and 1970s, argued that the
trajectory of ecosystems was less predictable than it had been assumed to
be, and urged that the emergence of properties at a systemic level but that
are not apparent at lower levels should be a focus of study.
5
However,
he did not repudiate the notion that ecosystems tend towards order and
harmony. Indeed, his view, that they have a strategy of development
towards an optimally diverse state within the constraints of energy
'
s bene
ows
and prevailing physical conditions, is strikingly similar to that of his
predecessors.
6
Although Odum concluded that ecosystems should, as far
as possible, be left in a natural state if they are to ful
l their potential, his
understanding of them bolstered the view that it would eventually be
possible to comprehend their operation in entirety and to manage them
so that production of the
they yield might be maximised.
7
'
goods
'
This con
dence in our ability to understand ecosystem behaviour has
been signi
cantly challenged and, to a large extent, replaced by two
3
S. K. Gaichas,
A Context for Ecosystem-based Fishery Management: Developing Concepts
of Ecosystems and Sustainability
'
'
(2008) 32 Marine Policy, 394; S. Bocking,
'
Visions of
Nature and Society: A History of the Ecosystem Concept
'
(1994) 20(3) Alternatives,12.
4
Gaichas,
'
Ecosystem-based Fishery Management
'
, 394.
5
Gaichas,
'
Ecosystem-based FisheryManagement
'
, 395; Bocking,
'
Visions of Nature
'
,14
-
15.
6
D. Worster,
in C. Pierce and D. VanDeVeer (eds) People,
Penguins, and Plastic Trees: Basic Issues in Environmental Ethics (Belmont, CA: Wadsworth
Publishing Company, 1995), p. 282; Gaichas,
'
The Ecology of Order and Chaos
'
,395;
S. Esbjörn-Hargens andM. E. Zimmerman, Integral Ecology: Uniting Multiple Perspectives on
the Natural World (Boston, MA: Integral Books, 2009), pp. 162
'
Ecosystem-Based Fishery Management
'
-
3.
7
Worster,
'
The Ecology of Order and Chaos
'
,pp.282
-
3.
