Parks - IUCN

JOHN WATSON AND PETER WILKINS
To realise this potential and reach
long-term objectives, an assessment of
habitats is being made to determine
those which are of most value for a
bioregional wildlife corridor network.
Characteristics that are being assessed
include:
❚ remnants with significant nature
conservation value. Factors to determine
conservation value include representation
of vegetation types within the current
protected area system, habitat values,
and the presence or absence of rare and
threatened flora and fauna;
❚ the location of remnant vegetation within the landscape which is necessary to
assess the degree of risk from threatening processes, such as rising groundwater (see
George et al. 1995). Vegetation along drainage-lines and other low-lying areas is
particularly vulnerable to salinity and/or waterlogging, whilst wind erosion is
adversely affecting small patches of remnant vegetation located high in the
landscape. It is also important to determine the degree to which threats can be
managed;
❚ the strategic location of vegetation within the landscape determines whether
native vegetation can be incorporated within a continuous corridor or used as part
of a ‘stepping stone’ corridor;
❚ the function of corridors for native fauna. Some groups of birds, large mammals,
larger reptiles, and possibly some flying insects may not have special requirements
for corridors, whereas small mammals, reptiles, many invertebrates, and plants are
most likely to require continuous habitat to survive along corridors (Wallace, 1998).
In addition, it may be that some fauna require corridors that comprise a ‘stepping
stone’ habitat arrangement, whereas other smaller species may require continuous
native vegetation to maintain ecological stability. The ‘focal species approach’ may
be used to maximise habitat adequacy for wildlife. This approach identifies threats
to wildlife and ranks species according to their sensitivity to a threat or threats. Those
species that are most sensitive become the focus for habitat reconstruction as it is
considered that creating or managing habitat for these species will also benefit a
range of other non-target species (Lambeck, 1997); and
❚ a knowledge of other land-uses, available resources, and the attitudes and the
requirements of land managers (both private and government agencies) to nature
conservation need to be considered.
This strategic approach is identifying areas of high biodiversity and conservation
value, which in turn is assisting in prioritising the need for connectivity and is
providing information on the likelihood of maintaining, improving, or creating
connectivity between these areas. For example, a strategic approach has identified
linkages to the Stirling Range National Park, and the Porongurup National Park from
the State Forest to the southwest (Figure 4).
Furthermore, information regarding the longevity of remnants and their value for
wildlife dispersal can be used to plan the best alignment and location for macro
corridors.
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'Stepping stone'
corridors are an
alternative to
continuous
corridors.