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IV. Conclusions
To some extent, the timber harvesting regime is superimposed on
the natural fire regime, it does not replace it. If there is
a significant adverse impact, the consequence for stands protected
only by the Code of Forest Practices is that the interval between
events may not be sufficiently long to ensure recovery of the
rainforest-sclerophyll forest ecotone from the incursion of edge
effects. Nor may it be long enough to ensure full recovery of
mature rainforest after other disturbances such as disease with
which adjacent timber harvesting activities may interact. Rainforest
protection measures must also consider the possibility that some
impacts such as weed invasion and disease represent change from
which there may be no recovery. Furthermore, because the Government's
definition of rainforest (CFL 1987) excludes most forest with
eucalypt emergents, there is little doubt that some of the mixed
forest and seral and transitional communities associated with
rainforest will be logged. These consequences will not be an
issue for those rainforest stands that are protected in conservation
reserves or within Special Protection Zones in State Forest, such
as many of those in East Gippsland.
At a landscape scale, the most important threats to rainforest
stands appear to be the potential of catastrophic fire to substantially
or permanently change the composition and distribution of rainforest
in Victoria and the risk of epidemic disease. These propositions
are more difficult to judge because our understanding of the processes
involved is even poorer than it is for edge effects at a local
scale, and relevant information is scarce. The resolution of
differences of scientific opinion and the implementation of management
strategies that ensure adequate protection may only be made by
the acquisition of empirical data. Until such data are acquired,
it is incumbent on planners to treat rainforest threats cautiously,
and to implement protection measures that will cope with the potential
for long-term and landscape scale impacts. Given that the Government
accepts the principle that forest management must provide for
the ecological sustainability of all rainforest values, rainforest
must be afforded the benefit of the doubt in areas where the values
are unique or irreplaceable, and where there is uncertainty about
the impacts that may result from management.
The data most urgently required for planning adequate protection
for rainforest include estimates of the background probability
of disease and fire events, together with the risks of impact
due to timber harvesting activities. There will necessarily be
a delay before these data are available. Approaches to obtaining
the necessary information upon which to base decisions are recommended
below.
It is not possible to say conclusively that impacts on rainforest
will be negligible or that they will be significant in the medium
or long term. Data from other temperate systems and analogous
communities in Tasmania suggest that significant medium or long-term
impacts are possible. In the absence of the necessary data on
natural disturbance regimes and the ecological processes affected
by management in Victoria, it is not possible to say if current
or stated practices are within the bounds of natural disturbance,
or if these practices are likely to result in unacceptable impacts.
Until the necessary data and understanding are available, a more
cautious approach to management is required than is currently
specified in CNR policy documents and the Code of Forest Practice.
The reason is that there is a prima facie case that current
management practices in timber utilisation areas have the potential
to elevate the risks of impact on some rainforest values in the
medium or long term, especially in those stands protected only
by the Code of Forest Practices for timber production. Forest
management practices that affect rainforest and associated ecosystems,
particularly harvesting and regeneration practices, should aim
to maintain or restore pre-disturbance species composition. Management
recommendations are made to mitigate the potential for adverse
impacts of management on rainforest. The research recommendations
aim to provide the most critical information as quickly and efficiently
as possible.
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