Logging/ timber harvesting and all associated processes lead to loss and fragmentation of habitat. It can also increase the risk of large fires through the creation of areas with uniformly dense fuel in the form of young trees and a heightened ignition risk. (DellaSala et al, 2004, Lindenmayer et al, 2009)

We know that western ringtail possums are more abundant in forest areas that have stayed unlogged for at least several decades and that they are highly sensitive to logging. (Wayne et al, 2006)
The Kingston Report (Wayne et al, 2000) pointed at reduced survivorship during the operations but also at declines as a delayed response to the logging.
Young trees will fill the gaps but also have high water requirements and might die off again in times of drought. It will take decades for them to become adequate sources of food and shelter for ringtail possums.

Any clearing operation will alter the forest structure and reduce canopy connectivity and leave gaps between stands which can only be traversed over the ground. As a consequence vulnerability to predation is greatly increased.
Food and shelter resources are diminished which leads to higher intra and inter-species competition. 
Removal of old hollow-bearing trees and short logging intervals that prevent new hollows from forming are a threat for all hollow-dependent arboreal marsupials and birds alike. (Lindenmayer et al, 2012)

decline of habitat trees