Along with logging the
NSW Scientific Committee[1] has acknowledged that extensive canopy dieback
is a threat likely to drive koalas to extinction. There are two major forms of
canopy dieback in the Five Forests.
Community concerns were first reported about the spread of Bell Miner Associated Dieback (BMAD) after the species spread downstream from logging operations into forests on private properties in 1994[2]. BMAD affects trees at lower topographies, in gullies and along streams. After this logging Bell-miners occupied all the filter strips of logged coupes in Murrah and Mumbulla State Forest.
Dieback Associated with Dry weather (DAD) affects much of the remaining 80% of forests on slopes and ridges and was first recorded in the Bateman Bioregion in early 1998[3]. This event was followed by a more prolonged officially declared drought between the years 2002 and 2004. Forests NSW observations[4] indicate that 46% of all coastal forests are affected being 36% of National Parks, 44% of State Forest and 70% of forest on private land.
Exacerbated by this unplanned disturbance most of the moister areas, about 20% of the total forest area, are declining with BMAD. In late 2008 the NSW Scientific Committee made a final determination to list BMAD as a key threatening process in New South Wales.
The Commonwealth’s Caring for our Country business plan (2008, pg 80) indicates the coastal forests in NSW subject to BMAD are priority areas for investing in management practices to decrease the risk of soil acidification, a soil limitation associated with dispersion, reduced water holding capacity and increasing soil toxicity[5].
Unfortunately, while NSW government agencies have noticed BMAD in the Five Forests, there is no mention of DAD in the final state-wide koala recovery plan produced by NSW Department of Environment and Climate Change and approved by the NSW Minister for Climate Change and the Environment in November 2008.
[1] NSW Scientific Committee, December 2007: Final determination for koalas occupying the coastal catchment between Dignams Creek and Wapengo.
[2] Department of Urban Affairs and Planning, 1996: Environmental Impact Assessment: Proposed Forestry Operation Eden Management Area 1994.
[3] Bertram, R. (2001) Endangered population nomination koalas occupying the coastal catchment between Dignams Creek and Wapengo in South East NSW. (www.fiveforests.net)
[4] Jaggers, J. (2004) Estimating the extent of declining forest in south east New South Wales: Unpublished, presented at the proceedings of a colloquium at Batemans Bay 18-19 November 2003. (eds. T.C.R. White and V. Jurskis) State Forests of NSW, Sydney.
[5] Tulau, M. (1997) Soil Landscapes of the Bega-Goalen Point 1:100,000 Sheet: Department of Land and Water Conservation, GPO Box 39, Sydney, NSW 2001.