Key words: Rainforest restoration, assisted natural regeneration, Lantana control, threatened species conservation
Wompoo Gorge is a private property located at Huonbrook in the Byron Shire hinterland, north coast NSW. The property provides a link between Nightcap and Goonengerry National Parks with Coopers Creek running along the eastern boundary. Originally covered by lowland subtropical rainforest with a stand of eucalypt forest extending down from the 100m high escarpment, half of the site was cleared early last century and partially converted to pasture and banana plantations. At the commencement of the project, the area contained various stages of rainforest regeneration and dense infestations of Lantana (Lantana camara). Twenty-seven threatened species (10 threatened flora species and 17 vulnerable animal species) have been recorded at Wompoo Gorge. The site has exceptional restoration potential and overall conservation significance.
An ongoing ecological restoration project is being implemented at the property, based on the recommendations of the Wompoo Gorge (South) Restoration Action Plan. In the three years to date, dense areas of Lantana in the area originally cleared have been controlled by mechanical means. A 4-wheel drive tractor was used to drive over and flatten Lantana over 2ha, returning a few weeks later to slash the Lantana. This method (first developed by Ralph Woodford at Rocky Creek Dam) resulted in the death of the majortiy of Lantana treated. Care was taken to aviod any existing regrowth of rainforest species near edges and regrowth patches.
Bush regeneration works have now been extended over an additional 14ha. A range of weed control techniques (including overspray and use of a splatter gun) have been used in the denser areas of Lantana not accessable by tractor. Hand weeding with brush hooks and loppers and cut/scrape and paint of Lantana is being undertaken in the more lightly invested native vegetation. Fruits from native plants on site have been collected and spread through out regeneration areas, adding to seed in the soil bank and that which is naturally distributed.
A monitoring program was established on site prior to the commencement of works. This included eight monitoring transects. Structural and floristic information was collated and photos taken prior to the commencement of works and then at the end of the first year. Data were entered into MERV (Monitoring and Evalution of the Restoration of Vegetation) database and used to produce reports.
Results. The previously dense Lantana areas have converted from weed to strongly regenerating rainforest by means of natural regeneration occurring over the 3 years since treatment. The areas first treated in Year 1, in particular the area where a tractor was used to control Lantana, have had impressive growth of native species, now up to a height of over 5 metres. Common regrowth species include White Cedar (Melia azederach), Trema (Trema tomentosa), Red Cedar (Toona ciliata), Tamarind, Sandpaper Fig (Ficus coronata), Bangalow Palm (Achontophoenix cunninghamiana), Brown Kurrajong (Commersonia bartramia), Stinging Tree (Dendrocnide excelsa), Pencil Cedar (Polyscias murrayi), Celerywood (Polyscias elegans), Blue Quandong (Elaeocarpus grandis), Black Bean (Castanospermum australe) and Sally Wattle (Acacia sp.). A strong mix of later phase rainforest species are also germinating. Groundcovers include Soft Braken Fern (Culcita dubia), Cunjevoi Lily (Alocasia brisbanensis), Juncus spp., Cyperus spp. and a range of basket grasses (including Oplismenus spp. and Ottochloa gracillima).
Lessons learned. As with all projects, follow-up weed control is essential to ensure that native species come to dominate the site in the long term. The project has recently gained funds to continue the works for a further 3 years. This will allow the project to to continue works into nearby areas where it is known that significant and sustainable environmental outcomes can be achieved on a cost effective basis.
Funding. The project is funding by a 3 year NSW Environmental Trust project with addtional support from the 2010 DECCW Great Eastern Ranges Initiative-Connectivity Conservation Incentives; the Northern Rivers CMA Invasive Species Weeds of National Significance program, and the EnviTE Jobs Fund and Green Jobs Corps teams. Further funding has been gained through the Raymond Borland Bequest Grants program and the Big Scrub Rainforest Landcare Group’s Caring for Our Country project.
Contact: Maree Thompson, EnviTE Inc, 56 Carrington Street (P.O.Box 1124), Lismore NSW 2480; Tel: +61 2 6621 9588, Email: email@example.com