Forest Stand Dynamics Drive a Conservation Conundrum for the Critically Endangered Leadbeater’s Possum

Abstract

Leadbeater’s possum (Gymnobelideus leadbeateri) is a critically endangered arboreal marsupial found primarily in the mountain ash forests of Victoria’s Central Highlands in southeastern Australia. It has two very specific and well-known habitat requirements: a dense, connected lower stratum of Acacia spp. for foraging and movement within the forest and hollow-bearing trees for nesting. Early habitat suitability models for Leadbeater’s possum focused primarily on the dynamics of the hollow-bearing tree component, assuming that sufficient Acacia persisted throughout the development of the stand. Recent research has highlighted the transient nature of the Acacia component in these forests and shown that old-growth forests are relatively poor habitat for Leadbeater’s possum. The stand dynamics of mountain ash forests mean that the presence and abundance of Acacia and hollow-bearing trees are largely independent of one another. This presents a fundamental conundrum for the conservation of Leadbeater’s possum – the Acacia component is associated with young, post-disturbance forests, whereas hollow-bearing trees are associated with older forests. Conservation-oriented silviculture needs to accommodate these dynamics and focus on the provision of both habitat elements in close proximity to each other in time and space. A landscape-scale approach that focuses on long-term habitat restoration and management will be critical to the long-term viability of Leadbeater’s possum, particularly in a warming climate.Keywords Acacia dealbata Eucalyptus regnans Habitat suitabilityConservation-oriented silviculture