The conservation of arboreal marsupials in the montane ash forests of the central highlands of Victoria, south-eastern Australia — VII. Modelling the persistence of Leadbeater's possum in response to modified timber harvesting practices

Abstract

A computer model for Population Viability Analysis (PVA) was used to simulate the relationship between the persistence of populations of the endangered species, Leadbeater's possum, Gymnobelideus leadbeateri and the implementation of a range of possible modified timber harvesting practices in two wood production blocks within the montane ash forests of the central highlands of Victoria, south-eastern Australia. The results of our analyses revealed that under the existing conservation strategies there was a high probability of extinction over the next 150 years in both blocks. Given that timber production areas comprise more than 75% of the distribution of G. leadbeateri, our findings highlight a need for additional conservation measures to enhance the survival prospects of the species. The range of upgraded conservation strategies that were examined included (1) extending the rotation time between logging operations; (2) modifying silvicultural practices to increase the amount of forest retained within each harvested coupe; and (3) permanently withdrawing areas from wood production. All of each of these approaches were found significantly to reduce the probability of extinction of populations of G. leadbeateri. However, when the relative merits of the various strategies were compared, the permanent withdrawal of potential logging coupes from timber harvesting was predicted to be the most efficient approach. Importantly, this strategy would have a number of practical advantages including that it overcomes both (1) the logistic difficulties of ensuring the long-term survival of retained trees within logged areas; and (2) human safety issues arising from implementing modified silvicultural practices. This practical application of PVA to compare the merits of different potential management options has provided new information that will enhance present efforts to conserve G. leadbeateri in wood production areas.

The occurrence of arboreal mammals in the rain forest fragments in the Anamalai Hills, south India

“…Nonetheless, it has been found that survival of species is related to several landscape and habitat variables such as the extent and quality of habitat (Lovejoy et al, 1986;Laurance, 1994;Lindenmayer and Possingham, 1995), connectivity between fragments (Lovejoy et al, 1986;Laurance, 1994;Lindenmayer et al, 1994), time since isolation and elevation (Lindenmayer et al, 1994), distance to the nearest fragment (Fitzgibbon, 1997) and location of the fragment in the landscape (Laurance 1990;Lindenmayer and Possingham, 1995).…”

Roost site selection and roosting behaviour in lesser short‐tailed bats(Mystacina tuberculata)in comparison with long‐tailed bats(Chalinolobus tuberculatus)inNothofagusforest, Fiordland

“…These behaviours make bats particularly vulnerable to reduction in abundance and quality of roosting habitat. Forests that are managed for timber production do not have as many cavity-bearing trees as unmodified forests (Mackowski 1984;Newton 1994;Lindenmayer & Possingham 1995). Therefore, it can be assumed that logging will reduce both abundance of cavities, and range of cavity sizes and quality.…”

Forest road and fuelbreak siting with respect to reference fire intensities

“…Stochastic methods of fire scenario development such as those used by Lindenmayer and Possingham (1995) may be useful as scientific model inputs but their reliance on random factors limits their utility as management planning tools. To provide an objective means of rating a road or road system it is then necessary to develop repeatable 'reference' fire conditions that road options may be judged against.…”