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large areas of unreserved land. They see this as the
only viable answer in the long term, requiring a
broad educational and political strategy to get there
(Woinarski et al. 1992; Price et al. 1995).

So, wildlife conservation must in part be con-
cerned with the practicalities of conserving outside
reserves. The Northern Territory example may
seem an extreme case when viewed from many
parts of the world, yet the argument surely applies
to some degree everywhere.

10.12 Does conservation biology need island theory?

Zimmerman and Bierregaard (1986) undertook an
analysis of Amazonian frogs which demonstrated
that knowledge of the autecological requirements
of the species would be critical to planning a
reserve system (not that a system would necessar-
ily be designed just for frogs). They undertook a
prediction by a species–area approach and showed
that it lacked relevance in the light of the available
autecological data. Frog species differ in the habitat
required for breeding: whereas some are strictly
streamside breeders, others require landlocked per-
manently or periodically flooded terra firmapools.
The authors concluded that if such data are avail-
able for enough species in the system being consid-
ered, then there need be no recourse to abstract
principles. If they are not available, it is still prefer-
able to conduct a rapid survey and collect biogeo-
graphic and ecological data. This is just one of
many studies that have championed empirical over
theoretical ‘island’ approaches. Does conservation
biology need island theories?

A non-equilibrium world?

Worthen (1996) bemoans the fact that the bias towards
species–area relationships over compositional–area
relationships continues to be a feature of the litera-
ture, including some of the most widely used intro-
ductory ecology texts. This bias continues despite
the demonstration, in numerous studies, of nested-
ness, community similarity of habitat fragments,
the relevance of successional patterns, and a variety

of other forms of compositional structure. These

non-random patterns in how communities assem-

ble, or alternatively how they change in response to

fragmentation, demand that we reappraise the con-

tribution of ‘island ecology’ within conservation

biology.

Much of the earlier applied island literature

seemed to assume that matrix contexts were

relatively insignificant and that stochastic decay

towards equilibrium would restore a new, depau-

perate balance. These were arguably useful simpli-

fying assumptions, but the behaviour of habitat

islands is perhaps more realistically captured

within the notions of flux of naturedescribed by

Pickettet al. (1992). This framework stresses physi-

cal as well as biotic processes (e.g. succession), the

role of episodic events (e.g. fires or hurricanes), and

the differing degrees of connectivity of populations

across ‘filtering’ landscapes. We have also seen that

the nature of the matrix can be crucial to what goes

on in the habitat islands within the landscape. How

much of this is ‘island biogeography’ is a moot

point, but insularity remains a key property and

issue within these other topics.

The application of equilibrium (EMIB) assump-

tions to reserve systems has been neatly critiqued

by Saunders et al. (1991, p. 23):

It is commonly assumed that at some stage the remnant

will re-equilibrate with the surrounding landscape. It is

however, questionable whether a new stable equilibrium

will be reached since the equilibration process is liable to

be disrupted by changing fluxes from the surrounding

matrix, disturbances, and influx of new invasive species.

The final equilibrium can be likened to an idealized end

point that is never likely to be reached, in much the same

fashion as the climatic climax is now conceptualized in

succession theory. Management of remnant areas will

thus be an adaptive process directed at minimizing poten-

tial future species losses.

The general premise of much of the applied

island biogeography literature is that (1) the alarm-

ing fragmentation of many ‘natural’ systems will

continue and therefore (2) if much wildlife is to sur-

vive, it will have to do so in reserve systems, and

that (3) we have very little time in which to act.

These concerns explain the initial attractiveness of

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