If the current reserve system in Victoria - both formal and informal - cannot save Leadbeater's Possum, why would just adding area to the formal reserve system will make a positive difference?
A substantial increase in the formal area of reserve in Victoria, by itself, would not "save" the possum. At the very least, such an increase would need to occur in conjunction with an even more substantial increase in funding and resources to offer a chance of success. It is myth that National Parks can simply be locked up and left to follow healthy and sustainable trends. In cases where reserves have been simply fenced in, the ecosystems often drift off to something unexpected and undesirable as the result of altered fire or flood regimes, or invasive species, or a combination of factors. Active management, resource intensive management, will be increasingly needed for our existing reserves to "save" species in the face of ecological change wrought by climate change and other human impacts. Extension of the reserve boundaries will have to consider active management and substantial increases in funding. No doubt this will be an uncomfortable debate for many people, but one that is needed.
These extra resources won't be just for an extension of the track system, or better maintenance of fire trails, or better rubbish removal, or even more research that describes the current populations. In the specific case of Leadbetter's possum, if the lack of habitat hollows is already a population threatening problem, and hollows are not being formed naturally at a sufficiently fast rate, then active management will be necessary to correct this imbalance - just waiting another 70 years and hoping everything survives that long is not a recipe for success. The predominant factor relating to hollow development is tree size, and Foresters especially trained in silviculture and forest ecology, know how to manipulate population pressures within a forest to ensure a minimum number of trees can grow to reach the size to support hollow development in the minimum amount of time. Further, they can appropriately "damage" the crown of appropriate trees to speed up hollow development. The wait for hollows to home the possum can be substantially reduced from 70 years with active management. But such an exercise is expensive, labour intensive and will require some trees to be felled.
An even greater problem for under-resourced reserves is that weeds will take natural advantage of increased stress caused by changes in fire regimes or climate. Similarly, pest populations will boom as natural control mechanisms falter under already observed changes. How will the existing reserve system cope if Australia suffers a pest outbreak like the mountain pine beetle experienced in Canada? What happens to the potential for control or mitigation if the reserve system is twice as large due to an under funded increase in area? Active management was seen as an essential part of coping with this pine beetle outbreak with the Canadian Government providing substantial funding to First Nations, communities and school districts for fuel management and hazard tree removal in post-infested areas, as well as recovering some costs by selling the killed timber.
Changed fire regimes in the US have changed the species composition and structure of the forests leading to more mega fires than ever before. Active management is being pursued in the U.S., and products are being sold to offset some of the costs of management. United States taxpayers are fully funding their program but American Professor Scott Stephens said about 40 per cent of the cost of implementing the program is covered by repurposing the cleared timber (i.e. selling it as garden mulch, woodchip, fence posts of even sawn lumber).
An increasing concern is that Eucalypts have particularly poor dispersal capabilities, so natural stands will be generally be unable to track changing climatic conditions. (Booth et al, 2015). Will active management be needed to translocate species to new environments? Species like the "pioneer" Eucalyptus that dominate after a fire, need bare ground at least 80 m from standing dominant trees for their seeds to germinate and grow well. However, if the climate warms and the rainfall patterns change as predicted in many reputable Australian climate models, will these large gaps of bare earth may become too hot and dry for successful natural regeneration? Will reserve workers need to manually plant and water seedlings to avoid a species change?
More money and resources need to be allocated to the existing Reserves and National Parks to give a chance to "save" what humans hold precious. Substantially more funding will be required if the area of reserves increases - there is little opportunity for "economies of scale" in the reserve system management because each additional hectare added is unique. Without a substantial increase in general tax payer funding the reserve managers need opportunities to co-fund their own maintenance and safe keeping. Payments for ecosystem services have long been held out as a way of generating these sorts of funds, but the mechanisms for such funding are far from developed and active. Sale of products extracted from the reserves, especially when the mass of those products may themselves be contributing to the problem, is a much more immediate source for funding.