Document ID: chunk:federal_register_of_legislation:F2024L00270:body:0:p25
Version: federal_register_of_legislation:F2024L00270
Segment Type: other
Provision Reference: 
Character Range: 68360–71309

of the remaining stags and other large old trees (Lindenmayer and Ough 2006).
Figure 4: Observed and projected changes in the average density of large hollow-bearing trees in mountain ash forests in the Central Highlands
Source: Figure derived from Lindenmayer et al. (2013b), reproduced with permission from David Lindenmayer.
The persistence of large hollow-bearing trees has shown a rapid decline in their abundance across the Central Highlands (Lindenmayer 1996b; Lindenmayer et al. 1997; Lindenmayer 2009; Lindenmayer and Wood 2010; Lindenmayer et al. 2011b; Lindenmayer et al. 2012; Lindenmayer et al. 2015a; Lindenmayer and Sato 2018). The observed and projected rate of decline in the density of large hollow-bearing trees in the Central Highlands (Lindenmayer et al. 2013b; Figure 4) is projected to continue until at least 2065 when new hollow-bearing trees will begin to be recruited (Lindenmayer and Sato 2018).
The 2009 bushfires reduced the abundance of hollow-bearing trees because much of the montane ash forest then burnt was regrowth from the 1939 bushfires or younger forest and thus too small to form hollows. The 2009 bushfires also substantially increased rates of loss of stags that remained after the 1939 fires (Lindenmayer et al. 2012; Lindenmayer et al. 2015a). Currently, the highest proportion of montane ash forest age class now comprises relatively young regrowth (particularly from the 2009 bushfires, but also following timber harvesting in recent decades). Little of the forest is dominated by stands of trees old enough to form hollows suitable for Leadbeater's possum (i.e., trees dating from prior to 1900) (Lindenmayer et al. 2015b; Figure 5). However, note that some of the forests dominated by younger stands do contain remnant living old trees or dead stags that contain hollows.
Figure 5: The age class of dominant trees in stands of montane ash forests in the Central Highlands
Note: Decade indicates the date at which the trees germinated.
Source: Reproduced with permission from 'Mountain Ash: Fire, Logging and the Future of Victoria's Giant Forests' by David Lindenmayer, David Blair, Lachlan McBurney and Sam Banks (2015b) and CSIRO Publishing.
Survival of Leadbeater's possum during the projected bottleneck in hollow-bearing trees will depend on protection of refuge habitats, particularly patches of multi-age and old-growth forest, and individual mature and senescent trees, as well as the success of new methods of den provisioning (for example, creation of hollows), translocations or other management actions. Recovery after the bottleneck is expected to depend on the extent of successful fire management and the effects of climate change.

Implications for conservation management
    * Management to reduce the likelihood of extensive and severe bushfire will be critical for the long-term persistence of Leadbeater's possum in montane ash forests.
    * The 1939 regrowth is, in most areas,