About the project
Why burn? What alternatives are there to burning?
It is about cleaning up the mess left behind from logging operations. Unless the timber debris is removed, the original forest of rainforest and tall eucalypts is unlikely to revegetate a site – even with restoration work the sites will take hundreds of years to return to their original forest composition.
Alternatives are mechanical disturbance and /or direct planting and seeding. This option is being trialled at Tyenna 42A where there is significant standing vegetation and burning is not feasible.
Direct planting and seeding are not usually a good alternative to burning because of the large quantities of timber debris from logging operations which cover the ground. Many species have a low survival rate from direct planting, a key factor being animal browsing.
Mechanical disturbance using machinery to clear timber debris, though sometimes appropriate to specific site circumstances, will usually have a higher impact through soil compaction and the subsequent increased risk of erosion. Ecological burning mimics the natural bushfire process including creating the desirable ash bed and helps understorey species as well as eucalypts to grow much faster. The end result of ecological burning has been found to be a mix of eucalypts and understorey species with very similar composition to forest that returns after a natural bushfire.
What about the rainforest species?
The Wylds Craig restoration site (Counsel 10B) is adjacent to mixed forest including myrtle, celery top pine, sassafras, and leatherwood. Care has been taken to ensure that the ecological burn of the site in 2014 did not impact on the values of adjacent rainforest. The shape and size of the coupe (>50% of logged area within one tree height of a forested edge) means that these rainforest species will colonise naturally from the adjacent native forest. In addition, there will be follow up planting of myrtle and leatherwood on the site. Options for other replanting trials are being investigated.
Will local seed be used?
Where possible we use only local provenance seed. The short time frame for this project means that for sites in 2014 some in-zone seed was also needed. Tasmania has about 50 mapped seed zones, and in-zone seed in the site areas has been found to have closely similar genetic composition to local seed. Recent research at UTAS also indicates that browsing animals favour the less healthy non-local seedlings so that the final forest composition will have a composition that is almost entirely local provenance.
The eucalyptus species composition of each of these forest sites was recorded by Forestry Tasmania prior to logging, and the seeding ratios used will reflect this. Other species recorded in pre-harvest assessments will come back through seed banks in the ground, seed from adjacent forest, or plantings.
Why pay FT to do these burns? Isn’t it their job anyway if they logged the coupes?
The Parks and Wildlife Service is the land manager but does not have the capacity or expertise to undertake ecological restoration burns in logged forests. Forestry Tasmania is working closely with the Parks and Wildlife Service to ensure that the project addresses ecological objectives. And without Environment Tasmania funding for this restoration project, the window of opportunity to successfully restore these sites would have been lost, as these restoration activities need to occur within a few years of logging.
How is this ecological restoration work different from Forestry Tasmania’s burns for production forest?
For this project we are doing low intensity ecological burns to help to restore a forest damaged by logging back to a natural state as soon as is possible.
Forestry Tasmania carries out intense burns that encourage the dense growth of a crop of eucalypts which would be cut down again after 40-80 years. Our ecological burns are less severe and help to reduce the logging debris that blocks the growth of new trees. Our emphasis is on restoring all the elements of the original forest, such as rainforest and understorey species - not just eucalypts.
It is a long-term process. Even with our help, an old-growth forest that has been damaged by clearfelling will take between 100 and 400 years to return to its previous state.
This project is about ecological restoration rather than creating production forests, and includes planting and seeding trials to favour rehabilitation of rainforest species and the understorey. Forestry Tasmania does not plant or seed understorey or rainforest species as part of its regeneration of trees for wood production. In addition, burns will be carried out to favour rainforest species by doing milder slower burning. Advice on methodology is being provided by UTAS plant ecologists and PWS / DPIPWE specialist staff.
Can these sites be logged in the future, given the collapse of the TFA?
All sites are managed by the Parks and Wildlife Service and have World Heritage status.
These sites are protected in perpetuity as part of the Tasmanian Wilderness World Heritage Area.