Principles and recommended tree species for revegetation
plantings on the Atherton Tablelands, North Queensland
Research Report
Nick Emtage, John Meadows and John Herbohn
School of Natural and Rural Systems Management, The
University of Queensland
ISBN 9781921359101
Published August 2008
Extract
The Wet Tropics bioregion, located on the coast and nearby
ranges of far northern Queensland between Ingham and Cooktown, is
one of the biodiversity ‘hotspots’ of the world. Far
North Queensland is world renowned for its highly productive
ecosystems including a spectacular variety and abundance of forest
communities.
The forests in the World Heritage area – mainly on the
eastern side of the Atherton Tablelands – and patches of
remnant forest within the agricultural landscape provide protected
habitat for unique endemic flora and fauna in the region. Just over
eighty percent of the bioregion is under wooded vegetation and
substantial areas are within the conservation reserve system under
World Heritage status. Despite the seemingly large areas of land in
conservation reserves, ecologists question whether these areas will
be sufficient to sustain biodiversity in the region into the
future. The most productive land in terms of the lands’ soil
types, topography and rainfall has been extensively cleared and
developed for agriculture. This land is not only the most
productive for agriculture; it also supported the highest levels of
biodiversity in the region in the past. The clearing of native
vegetation has adversely affected the ecosystems that were specific
to these parts of the region. While the land within the World
Heritage Area is thought to be in relatively good condition for the
conservation of biodiversity, assessment of land outside the
reserve system is rated as generally in ‘fair’
condition and in need of rehabilitation.
The greatest clearing of native vegetation in Australia has been
undertaken for the purpose of expanding agriculture. This has
resulted in a ‘fragmented landscape’, with remnant
vegetation in these parts retained in small, isolated patches. The
size, shape and isolation of these patches of remnant vegetation
leave them susceptible to degradation. Rapidly growing population
levels are leading to an intensification of land uses in the
region. While broad-scale clearing has reduced in the State
following the passing of the Queensland Vegetation Management
Act (1997) and subsequent amendments, the development of
housing and associated infrastructure has the potential to further
reduce and degrade remnant vegetation areas.
The responses of communities and government agencies to the
degradation of natural vegetation include increasing the areas of
land in the public reserve system, the development of plans for
natural resource management and urban development, and a range of
rehabilitation and revegetation projects by private landholders and
community groups. The planning strategies have sought to
identify and prioritise parts of the region that are under
particular threat and those areas which, if rehabilitated, would
provide the most substantial contributions to improving the health
of the natural environment. Often the focus is on replanting
riparian areas, protecting the edges of remnant patches of
vegetation and restoring connectivity between patches.
A number of community groups interested in natural resource
management are involved in revegetation programs whose purpose is
to improve ecosystem functioning. Timber plantations and
revegetation programs can have positive and negative effects on the
environmental values of a landscape depending on the management
practices applied, choice of species, and place in the landscape
that is developed. These revegetation efforts and the
rehabilitation of remnant vegetation areas are the focus of this
report.
The
objectives for this report are to:
-
Provide an overview of the current status of biodiversity in the
Wet Tropics region;
-
Examine the processes affecting biodiversity conservation in the
Wet Tropics region;
-
Review the outcomes of studies that have investigated the
potential biodiversity impacts of revegetation programs;
-
Identify design and management principles that can maximise the
positive impacts of revegetation programs on biodiversity
conservation; and
-
Report the results of a study to identify the optimal species to
use in revegetation and rehabilitation programs in the Atherton
Tablelands sub-region of the Wet Tropics.