New Book Announcement

[McComas]

'Risk of Extinction: Ranking management options for Leadbeater's Possum 
using Population Viability Analysis. DB Lindenmayer and HP Possingham. 
Australian National University, Centre for Resource and Environmental 
Studies. Canberra. 204pp. A$20 + $5 handling ($10 international 
handling).

Details: e-mail: publications at cres.anu.edu.au

WWW Site and ofer form : http://cres20.anu.edu.au/possum/possum.html

Abstract

This book by David Lindenmayer and Hugh Possingham contains 
recommendations for forest management to minimise the chance of 
extinction of Leadbeater's Possum (Gymnobelideus leadbeateri. These 
recommendations are based on the consideration of the biology of 
Leadbeater's Possum and an extensive population simulation study in which 
the likelihood of extinction of the species was assessed under a wide 
range of scenarios. A brief overview of Population Viability Analysis 
(PVA) is outlined in Chapter 1. 

The computer simulation model (ALEX) that was applied in this study is 
described in Chapter 2. Chapter 3 contains a short summary of aspects of 
the biology and ecology of Leadbeater's Possum relevant to our 
investigation. Key results from PVA are presented in Chapters 4-7. 
Baseline explorations of the dynamics of populations of Leadbeater's 
Possum within existing patches of suitable habitat are described in 
Chapter 4.

An investigation of population behaviour resulting from catastrophic 
wildfire events is outlined in Chapter 5. Further complexity is added to 
our analyses in Chapter 6, in which we model the impacts of disturbances 
arising from a combination of fire and logging operations. In that 
chapter, the relative merits of different management strategies for the 
conservation of Leadbeater's Possum within wood production forests is 
examined. 

Given that a major outcome of Chapter 6 was that the permanent 
reservation of key forest patches was one of the most useful conservation 
strategies, the analyses in Chapter 7 focus on aspects of reserve size, 
position and number. Notably, in many parts of Chapters 6 and 7 we have 
concentrated on ranking different management options. In these cases we 
are primarily concerned with the relative effectiveness of different 
conservation strategies rather than precise values for the probability of 
extinction.

The key findings and conclusions associated with each phase of analysis 
are presented in several places in this document. A brief overview of the 
results is given in the Executive Summary at the front of the book, 
together with key recommendations for forest management to enhance 
long-term conservation strategies for Leadbeater's Possum. In addition, 
there are Summary and Conclusions sections accompanying each chapter 
where we completed PVA.

Finally, in Chapter 8 we present a synthesis of some of the key findings 
of the study. An important part of PVA is to understand the limitations 
of the analyses that have been completed. On this basis, an Assumptions 
and Limitations section accompanies each chapter in which the results of 
analyses are presented.