A method for predicting the spatial distribution of arboreal marsupials

1995 ◽  
Vol 22 (4) ◽  
pp. 445 ◽  
Author(s):  
DB Lindenmayer ◽  
K Ritman ◽  
RB Cunningham ◽  
JBD Smith ◽  
D Horvath
Keyword(s):  
Spatial Distribution ◽  
Kernel Smoothing ◽  
Eucalyptus Regnans ◽  
Field Surveys ◽  
Probability Of Occurrence ◽  
Predicted Probability ◽  
Arboreal Marsupials ◽  
Large Trees ◽  
Mountain Ash ◽  
Smoothing Procedure

A method is described for predicting the spatial distribution of arboreal marsupials. The approach is demonstrated using a statistical habitat association model for the greater glider (Petauroides volans), developed in the mountain ash (Eucalyptus regnans) forests of the central highlands of Victoria. The method is applied to predict the spatial distribution of P. volans in the Ada Forest Block, using forestinventory data on the values of the two significant variables in the statistical model (the age of a stand of forest and the abundance of large trees with hollows in a 3-ha area). The application of the model enabled values for the estimated probability of occurrence of P, volans (with a 95% confidence interval) to be generated for each of approximately 2200 3-ha pixels in the Ada Forest Block. A kernel smoothing procedure was then applied to allow for the spatial dependence implicit in these data. The standard measures of statistical uncertainty employed in our analysis revealed substantial variation in the predicted probability of occurrence of P. volans, even though the terms in the statistical relationship were highly significant. However, whilst the model is unable to reliably predict the occurrence of P. volans at any given 3-ha site, tests of the performance of the model showed that it performed well when the results of field surveys were aggregated over many sites. The results of our analysis emphasise the importance of including measures of uncertainty in spatial predictions generated from statistical models.

The use of topographic fire refuges by the greater glider (Petauroides volans) and the mountain brushtail possum (Trichosurus cunninghami) following a landscape-scale fire

2015 ◽  
Vol 37 (1) ◽  
pp. 39 ◽  
Author(s):  
Laurence E. Berry ◽  
Don A. Driscoll ◽  
Samuel C. Banks ◽  
David B. Lindenmayer
Keyword(s):  
Forest Ecosystem ◽  
Landscape Scale ◽  
Brushtail Possum ◽  
Crown Fire ◽  
Eucalyptus Regnans ◽  
Additional Work ◽  
Arboreal Marsupials ◽  
Mountain Ash ◽  
Central Highlands ◽  
Burnt Areas

We examined the abundance of arboreal marsupials in topographic fire refuges after a major fire in a stand-replacing crown-fire forest ecosystem. We surveyed the abundance of arboreal marsupials across 48 sites in rainforest gullies burnt to differing extents by the 2009 fires in the mountain ash (Eucalyptus regnans) forests of the Victorian Central Highlands, Australia. The greater glider (Petauroides volans) was less abundant within the extent of the 2009 fire. The mountain brushtail possum (Trichosurus cunninghami) was more abundant within the extent of the 2009 fire, particularly within unburnt peninsulas protruding into burnt areas from unburnt edges. Our results indicate that fire refuges may facilitate the persistence of some species within extensively burnt landscapes. Additional work should seek to clarify this finding and identify the demographic mechanisms underlying this response.

The influence of time since fire and distance from fire boundary on the distribution and abundance of arboreal marsupials in Eucalyptus regnans-dominated forest in the Central Highlands of Victoria

2002 ◽  
Vol 29 (2) ◽  
pp. 151 ◽  
Author(s):  
R. van der Ree ◽  
R. H. Loyn
Keyword(s):  
Brushtail Possum ◽  
Age Classes ◽  
Eucalyptus Regnans ◽  
Salvage Logging ◽  
Age Class ◽  
Time Since Fire ◽  
Arboreal Marsupials ◽  
Mountain Ash ◽  
Central Highlands ◽  
The Impact

The impact of time since fire after two consecutive wildfires 44 years apart (1939 and 1983) within the same area, and the distance from the fire boundary (<100 m or 500-2000 m), were investigated in relation to the distribution and abundance of arboreal marsupials in 1994. Arboreal marsupials were censused by stagwatching and spotlighting in two relatively young age classes of mountain ash (Eucalyptus regnans) dominated forest in the Central Highlands of Victoria. Five species of arboreal marsupial were detected, but only three were detected in sufficient numbers to determine habitat preferences. Petauroides volans (greater glider) was statistically more abundant in 1939 regrowth forests, while Trichosurus caninus (mountain brushtail possum) showed no significant preference for either age class of forest. All but one record of Gymnobelideus leadbeateri (Leadbeater's possum) came from young forest, though the effect of age-class was not statistically significant. Distance from fire boundary explained little or no variation in mammal distribution or abundance. While the actual number of hollow-bearing trees was similar in both age classes of forest, the long-term lifespan of hollow-bearing trees in more recently burnt forest is predicted to be lower than in unburnt or not recently burnt forest. Post-fire salvage logging following the 1983 wildfires appears to have reduced the number of hollow-bearing trees at sites burnt in 1983.

Long-term patterns in the decay, collapse, and abundance of trees with hollows in the mountain ash (Eucalyptus regnans) forests of Victoria, southeastern Australia

2010 ◽  
Vol 40 (1) ◽  
pp. 48-54 ◽  
Author(s):  
David B. Lindenmayer ◽  
Jeff T. Wood
Keyword(s):  
Population Dynamics ◽  
Structural Complexity ◽  
Time Dependent ◽  
Old Growth ◽  
Eucalyptus Regnans ◽  
Southeastern Australia ◽  
Large Trees ◽  
Mountain Ash ◽  
Over Time

Large trees with hollows are an important component of stand structural complexity worldwide. Understanding their population dynamics is needed to manage cavity-dependent biota. We quantified long-term rates of collapse of 302 measured trees with hollows in 1939-aged regrowth mountain ash ( Eucalyptus regnans F. Muell.) forest in southeastern Australia. We identified time-dependent dynamics in which the collapse rates of trees slowed from ∼4% annually between 1983 and 1993 to ∼2.2% between 1993 and 2007. Transitions of trees between different decay states (forms) also slowed over time. Nevertheless, during the 24-year period of our study, over half of our marked and measured trees had fallen, but there was no recruitment of new trees with hollows. Under current projections, few trees with hollows will occur on our field sites by ∼2050, although more had been forecast in earlier investigations. Such a paucity of trees with hollows in extensive areas of regrowth mountain ash forests will lead to a shortage of nesting and sheltering sites for cavity-dependent biota. We suggest a short–medium (10- to 100-year) focus on the conservation of old growth and multi-aged stands will be needed to maintain populations of those species strongly associated with trees with hollows in mountain ash forests.

scholarly journals A Bioclimate-Based Maximum Entropy Model for Comperiella calauanica Barrion, Almarinez and Amalin (Hymenoptera: Encyrtidae) in the Philippines

Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 26
Author(s):  
Billy Joel M. Almarinez ◽  
Mary Jane A. Fadri ◽  
Richard Lasina ◽  
Mary Angelique A. Tavera ◽  
Thaddeus M. Carvajal ◽  
...  
Keyword(s):  
Maximum Entropy ◽  
Habitat Suitability ◽  
Species Distribution Model ◽  
Biological Control Agent ◽  
The Philippines ◽  
Distribution Model ◽  
Field Surveys ◽  
Probability Of Occurrence ◽  
Precipitation Seasonality ◽  
Bioclimatic Variables

Comperiella calauanica is a host-specific endoparasitoid and effective biological control agent of the diaspidid Aspidiotus rigidus, whose outbreak from 2010 to 2015 severely threatened the coconut industry in the Philippines. Using the maximum entropy (Maxent) algorithm, we developed a species distribution model (SDM) for C. calauanica based on 19 bioclimatic variables, using occurrence data obtained mostly from field surveys conducted in A. rigidus-infested areas in Luzon Island from 2014 to 2016. The calculated the area under the ROC curve (AUC) values for the model were very high (0.966, standard deviation = 0.005), indicating the model’s high predictive power. Precipitation seasonality was found to have the highest relative contribution to model development. Response curves produced by Maxent suggested the positive influence of mean temperature of the driest quarter, and negative influence of precipitation of the driest and coldest quarters on habitat suitability. Given that C. calauanica has been found to always occur with A. rigidus in Luzon Island due to high host-specificity, the SDM for the parasitoid may also be considered and used as a predictive model for its host. This was confirmed through field surveys conducted between late 2016 and early 2018, which found and confirmed the occurrence of A. rigidus in three areas predicted by the SDM to have moderate to high habitat suitability or probability of occurrence of C. calauanica: Zamboanga City in Mindanao; Isabela City in Basilan Island; and Tablas Island in Romblon. This validation in the field demonstrated the utility of the bioclimate-based SDM for C. calauanica in predicting habitat suitability or probability of occurrence of A. rigidus in the Philippines.

Does nitrogen limit the growth of native eucalypt forests:some observations for mountain ash (Eucalyptus regnans)

2001 ◽  
Vol 52 (1) ◽  
pp. 111 ◽  
Author(s):  
P. M. Attiwill ◽  
P. M. Attiwill ◽  
B. M. May ◽  
B. M. May
Keyword(s):  
N Availability ◽  
Ecological Research ◽  
Biological Fixation ◽  
Ecological Processes ◽  
Eucalyptus Regnans ◽  
Rate Of Growth ◽  
Wild Fire ◽  
N Supply ◽  
Eastern Australia ◽  
Mountain Ash

It is often stated that the availability of N limits the rate of growth of native forests. We discuss this hypothesis with particular reference to the mountain ash (Eucalyptus regnans) forests of south-eastern Australia. The abundance of 15 N in leaves and soil of mountain ash forest is in accord with data for Northern Hemisphere temperate forests and for tropical forests,and indicates that N availability is relatively high.None of the nutrient elements has limited the rate of growth of mountain ash forest regenerating after major disturbance (clear-felling and intense wild-fire). There is some evidence that P may be limiting to some ecological processes (e.g. the rate of litter decomposition). We conclude that phosphorus is more likely to be limiting than nitrogen in mountain ash forest because nitrogen cycling is conservative and continual inputs of N through biological fixation supplement this conservative N supply, and the stands never become N-deficient. The development of methodologies to determine the rate of N2-fixation in forests should be of high priority in ecological research.

Economics of a nest-box program for the conservation of an endangered species: a reappraisal

2001 ◽  
Vol 31 (11) ◽  
pp. 1992-2003 ◽  
Author(s):  
Daniel A Spring ◽  
Michael Bevers ◽  
John OS Kennedy ◽  
Dan Harley
Keyword(s):  
Net Present Value ◽  
Population Recovery ◽  
Optimal Management ◽  
Present Value ◽  
Eucalyptus Regnans ◽  
Nest Boxes ◽  
Mountain Ash ◽  
Local Abundance ◽  
Leadbeater's Possum

An optimization model is developed to identify timing and placement strategies for the installation of nest boxes and the harvesting of timber to meet joint timber–wildlife objectives. Optimal management regimes are determined on the basis of their impacts on the local abundance of a threatened species and net present value (NPV) and are identified for a range of NPV levels to identify production possibility frontiers for abundance and NPV. We apply the model to a case study focusing on an area of commercially productive mountain ash (Eucalyptus regnans F. Muell.) forest in the Central Highlands region of Victoria, Australia. The species to be conserved is Leadbeater's possum (Gymnobelideus leadbeateri McCoy), which is locally limited by a scarcity of nesting hollows. The modeling is exploratory but indicates that nest boxes may offer a promising population recovery tool if consideration is taken of their placement and areal extent through time.

Mountain Ash

2015 ◽  
Author(s):  
David Lindenmayer ◽  
David Blair ◽  
Lachlan McBurney ◽  
Sam Banks
Keyword(s):  
Forest Ecosystems ◽  
Fire Severity ◽  
Fire Dynamics ◽  
High Severity ◽  
Fire Environment ◽  
Arboreal Marsupials ◽  
New Findings ◽  
Mountain Ash ◽  
Old Trees ◽  
Very High

Mountain Ash draws together exciting new findings on the effects of fire and on post-fire ecological dynamics following the 2009 wildfires in the Mountain Ash forests of the Central Highlands of Victoria. The book integrates data on forests, carbon, fire dynamics and other factors, building on 6 years of high-quality, multi-faceted research coupled with 25 years of pre-fire insights. Topics include: the unexpected effects of fires of varying severity on populations of large old trees and their implications for the dynamics of forest ecosystems; relationships between forest structure, condition and age and their impacts on fire severity; relationships between logging and fire severity; the unexpectedly low level of carbon stock losses from burned forests, including those burned at very high severity; impacts of fire at the site and landscape levels on arboreal marsupials; persistence of small mammals and birds on burned sites, including areas subject to high-severity fire, and its implications for understanding how species in this group exhibit post-fire recovery patterns. With spectacular images of the post-fire environment, Mountain Ash will be an important reference for scientists and students with interests in biodiversity, forests and fire.

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