Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Geoffrey J. Cary is active.

Publication


Featured researches published by Geoffrey J. Cary.


Landscape Ecology | 2006

Comparison of the sensitivity of landscape-fire-succession models to variation in terrain, fuel pattern, climate and weather

Geoffrey J. Cary; Robert E. Keane; Robert H. Gardner; Sandra Lavorel; Mike D. Flannigan; Ian D. Davies; Chao Li; James M. Lenihan; T. Scott Rupp; Florent Mouillot

The purpose of this study was to compare the sensitivity of modelled area burned to environmental factors across a range of independently-developed landscape-fire-succession models. The sensitivity of area burned to variation in four factors, namely terrain (flat, undulating and mountainous), fuel pattern (finely and coarsely clumped), climate (observed, warmer & wetter, and warmer & drier) and weather (year-to-year variability) was determined for four existing landscape-fire-succession models (EMBYR, FIRESCAPE, LANDSUM and SEM-LAND) and a new model implemented in the LAMOS modelling shell (LAMOS(DS)). Sensitivity was measured as the variance in area burned explained by each of the four factors, and all of the interactions amongst them, in a standard generalised linear modelling analysis. Modelled area burned was most sensitive to climate and variation in weather, with four models sensitive to each of these factors and three models sensitive to their interaction. Models generally exhibited a trend of increasing area burned from observed, through warmer and wetter, to warmer and drier climates with a 23-fold increase in area burned, on average, from the observed to the warmer, drier climate. Area burned was sensitive to terrain for FIRESCAPE and fuel pattern for EMBYR. These results demonstrate that the models are generally more sensitive to variation in climate and weather as compared with terrain complexity and fuel pattern, although the sensitivity to these latter factors in a small number of models demonstrates the importance of representing key processes. The models that represented fire ignition and spread in a relatively complex fashion were more sensitive to changes in all four factors because they explicitly simulate the processes that link these factors to area burned.


PLOS ONE | 2012

Land management practices associated with house loss in wildfires

Philip Gibbons; Linda van Bommel; A. Malcolm Gill; Geoffrey J. Cary; Don A. Driscoll; Ross A. Bradstock; Emma Knight; Max A. Moritz; Scott L. Stephens; David B. Lindenmayer

Losses to life and property from unplanned fires (wildfires) are forecast to increase because of population growth in peri-urban areas and climate change. In response, there have been moves to increase fuel reduction—clearing, prescribed burning, biomass removal and grazing—to afford greater protection to peri-urban communities in fire-prone regions. But how effective are these measures? Severe wildfires in southern Australia in 2009 presented a rare opportunity to address this question empirically. We predicted that modifying several fuels could theoretically reduce house loss by 76%–97%, which would translate to considerably fewer wildfire-related deaths. However, maximum levels of fuel reduction are unlikely to be feasible at every house for logistical and environmental reasons. Significant fuel variables in a logistic regression model we selected to predict house loss were (in order of decreasing effect): (1) the cover of trees and shrubs within 40 m of houses, (2) whether trees and shrubs within 40 m of houses was predominantly remnant or planted, (3) the upwind distance from houses to groups of trees or shrubs, (4) the upwind distance from houses to public forested land (irrespective of whether it was managed for nature conservation or logging), (5) the upwind distance from houses to prescribed burning within 5 years, and (6) the number of buildings or structures within 40 m of houses. All fuel treatments were more effective if undertaken closer to houses. For example, 15% fewer houses were destroyed if prescribed burning occurred at the observed minimum distance from houses (0.5 km) rather than the observed mean distance from houses (8.5 km). Our results imply that a shift in emphasis away from broad-scale fuel-reduction to intensive fuel treatments close to property will more effectively mitigate impacts from wildfires on peri-urban communities.


International Journal of Wildland Fire | 2011

Prescribed burning: how can it work to conserve the things we value?

Trent D. Penman; Fiona Christie; Alan N. Andersen; Ross A. Bradstock; Geoffrey J. Cary; M. K. Henderson; Owen F. Price; C. Tran; Glenda M. Wardle; Richard J. Williams; Alan York

Prescribed burning is a commonly applied management tool, and there has been considerable debate over the efficacy of its application. We review data relating to the effectiveness of prescribed burning in Australia. Specifically, we address two questions: (1) to what extent can fuel reduction burning reduce the risk of loss of human life and economic assets posed from wildfires? (2) To what extent can prescribed burning be used to reduce the risk of biodiversity loss? Data suggest that prescribed burning can achieve a reduction in the extent of wildfires; however, at such levels, the result is an overall increase in the total area of the landscape burnt. Simulation modelling indicates that fuel reduction has less influence than weather on the extent of unplanned fire. The need to incorporate ecological values into prescribed burning programmes is becoming increasingly important. Insufficient data are available to determine if existing programs have been successful. There are numerous factors that prevent the implementation of better prescribed burning practices; most relate to a lack of clearly defined, measurable objectives. An adaptive risk management framework combined with enhanced partnerships between scientists and fire-management agencies is necessary to ensure that ecological and fuel reduction objectives are achieved.


Biological Conservation | 1996

Conservation conflicts over burning bush in south-eastern Australia

David A. Morrison; Rodney T. Buckney; Belinda J. Bewick; Geoffrey J. Cary

Current fire management practices in the fire-prone vegetation of south-eastern Australia are based mainly on the concept of hazard reduction via the use of periodic low-intensity fires to maintain the amount of flammable fuel within specified (low) limits. We examined the possible conflict between the requirements of fire management for hazard reduction and requirements for species conservation in the dry-sclerophyll shrublands and woodlands of the Sydney region. Our data indicate that potentially severe fire hazards (fine fuel loads of ≥10 t.ha−1) can reappear in the woodland and shrubland vegetation within 2–4 years after low-intensity fires, such as are typical of the fuel-reduction burns usually prescribed. Our data also show that low-intensity fires will have significant effects on the species composition of the communities if they occur with an inter-fire interval of less than 7–8 years, causing a significantly reduced abundance of long-lived woody shrub species. There is thus a clear conflict in south-eastern Australia between fire management practices based solely on prescribed burning for hazard reduction and the fire management practices necessary to maintain ecosystem biodiversity, and this conflict is greatest for fire-sensitive shrub species. The conflict between these two vegetation management objectives cannot be resolved by a simple compromise, as prescribed fires with inter-fire intervals any greater than 4 years will allow a potentially severe fire hazard to exist, while a burning regime with any inter-fire intervals less than 8 years will result in loss of biodiversity. This conflict means that it will probably not be possible to achieve simultaneously both hazard reduction and species conservation for any specified managed area.


Trends in Ecology and Evolution | 2013

How does ecological disturbance influence genetic diversity

Sam C. Banks; Geoffrey J. Cary; Annabel L. Smith; Ian D. Davies; Don A. Driscoll; A. Malcolm Gill; David B. Lindenmayer; Rod Peakall

Environmental disturbance underpins the dynamics and diversity of many of the ecosystems of the world, yet its influence on the patterns and distribution of genetic diversity is poorly appreciated. We argue here that disturbance history may be the major driver that shapes patterns of genetic diversity in many natural populations. We outline how disturbance influences genetic diversity through changes in both selective processes and demographically driven, selectively neutral processes. Our review highlights the opportunities and challenges presented by genetic approaches, such as landscape genomics, for better understanding and predicting the demographic and evolutionary responses of natural populations to disturbance. Developing this understanding is now critical because disturbance regimes are changing rapidly in a human-modified world.


International Journal of Wildland Fire | 2009

Relative importance of fuel management, ignition management and weather for area burned: evidence from five landscape–fire–succession models

Geoffrey J. Cary; Mike D. Flannigan; Robert E. Keane; Ross A. Bradstock; Ian D. Davies; James M. Lenihan; Cheng Li; K. A. Logan; Russell A. Parsons

The behaviour of five landscape fire models (CAFE, FIRESCAPE, LAMOS(HS), LANDSUM and SEM- LAND) was compared in a standardised modelling experiment. The importance of fuel management approach, fuel management effort, ignition management effort and weather in determining variation in area burned and number of edge pixels burned (a measure of potential impact on assets adjacent to fire-prone landscapes) was quantified for a standardised modelling landscape. Importance was measured as the proportion of variation in area or edge pixels burned explained by each factor and all interactions among them. Weather and ignition management were consistently more important for explaining variation in area burned than fuel management approach and effort, which were found to be statistically unimportant. For the number of edge pixels burned, weather and ignition management were generally more important than fuel management approach and effort. Increased ignition management effort resulted in decreased area burned in all models and decreased number of edge pixels burned in three models. The findings demonstrate that year-to-year variation in weather and the success of ignition management consistently prevail over the effects of fuel management on area burned in a range of modelled ecosystems.


Journal of Environmental Management | 2012

Wildfires, fuel treatment and risk mitigation in Australian eucalypt forests: Insights from landscape-scale simulation

Ross A. Bradstock; Geoffrey J. Cary; Ian D. Davies; David B. Lindenmayer; Owen F. Price; Richard J. Williams

Wildfires pose significant risks to people and human infrastructure worldwide. The treatment of fuel in landscapes may alter these risks but the magnitude of this effect on risk is poorly understood. Evidence from Australian Eucalyptus forests suggests that mitigation of risk using prescribed burning as a fuel treatment is partial because weather and fuel dynamics are conducive to regular high intensity fires. We further examine the response of risk to treatment in eucalypt forests using landscape simulation modelling. We model how five key measures of wildfire activity that govern risk to people and property may respond to variations in rate and spatial pattern of prescribed fire. We then model effects of predicted climate change (2050 scenarios) to determine how the response of risk to treatment is likely to be altered in the future. The results indicate that a halving of risk to people and property in these forests is likely to require treatment rates of 7-10% of the area of the landscape per annum. Projections of 2050 weather conditions under climate change further substantially diminished the effect of rate of treatment. A large increase in rates of treatment (i.e. circa. 50% over current levels) would be required to counteract these effects of climate change. Such levels of prescribed burning are unlikely to be financially feasible across eucalypt dominated vegetation in south eastern Australia. Despite policy imperatives to expand fuel treatment, a reduction rather than an elimination of risk will result. Multi-faceted strategies will therefore be required for the management of risk.


Frontiers in Ecology and the Environment | 2013

Forest fire management, climate change, and the risk of catastrophic carbon losses

David M. J. S. Bowman; Brett P. Murphy; Mathias Boer; Ross A. Bradstock; Geoffrey J. Cary; Mark A. Cochrane; Rodderick J Fensham; Meg A. Krawchuk; Owen F. Price; Richard J. Williams

Approaches to management of fireprone forests are undergoing rapid change, driven by recognition that technological attempts to subdue fire at large scales (fire suppression) are ecologically and economically unsustainable. However, our current framework for intervention excludes the full scope of the fire management problem within the broader context of fire−vegetation−climate interactions. Climate change may already be causing unprecedented fire activity, and even if current fires are within the historical range of variability, models predict that current fire management problems will be compounded by more frequent extreme fire-conducive weather conditions (eg Fried et al. 2004). Concern about climate change has also made the mitigation of greenhouse-gas (GHG) emissions and increased carbon (C) storage a priority for forest managers.


International Journal of Wildland Fire | 2008

The relative importance of fine-scale fuel mosaics on reducing fire risk in south-west Tasmania, Australia

Karen J. King; Ross A. Bradstock; Geoffrey J. Cary; Joanne Chapman; Jb Marsden-Smedley

In many landscapes, an important fire management objective is to reduce the negative impacts from unplanned fires on people, property and ecological values. In Australia, there exists an inherent assumption that high spatial variability in fire ages and hence fuel loads will have negative effects on both the incidence and spread of subsequent fires, and will enhance ecological values. A recent study using the process-based computer simulation model FIRESCAPE-SWTAS predicted several relationships between prescribed burn treatment levels and spatial patterning and management objectives in south-west Tasmania, Australia. The present study extended this investigation to additionally explore the effects of prescribed burning treatment unit size on unplanned fire incidence and area burned both in the general landscape and specifically in fire-intolerant vegetation. Simulation results suggest that treatment level had the greatest influence on modifying fire effects, whereas treatment unit size had the least effect. The model predicted that all three parameters interacted to determine the mean annual area burnt by unplanned fires. In fire-intolerant vegetation, treatment unit size did not influence the incidence of unplanned fires and the area burnt by unplanned fires in these communities. Where significant differences were evident, fire risk was reduced by higher treatment levels, deterministic spatial patterns of burning units, and smaller burning unit sizes.


International Journal of Wildland Fire | 2006

Simulation of prescribed burning strategies in south-west Tasmania, Australia: effects on unplanned fires, fire regimes, and ecological management values

Karen J. King; Geoffrey J. Cary; Ross A. Bradstock; Joanne Chapman; Adrian Pyrke; Jonathon B. Marsden-Smedley

Computer simulation modelling provides a useful approach for determining the trade-offs between the extent of prescribed burning and the long-term impacts of unplanned fires on management values. In the present study, FIRESCAPE-SWTAS, a process-based fire regime and vegetation dynamics model, was used in the World Heritage Area of south-west Tasmania, Australia, to investigate the implications of different prescribed burning treatments on identified management objectives. Treatments included annual prescribed burning of different proportions of the most flammable vegetation community, buttongrass moorlands. Additionally, a proposed strategic burning treatment for this landscape was simulated for comparison with these treatments. Simulations identified the nature of the relationships between the prescribed burn treatment level and the fire size distributions, the mean incidence, and the mean annual areas burnt by unplanned fires, with all three parameters declining with increases in treatment level. The study also indicated that strategically located treatment units were able to enhance the reduction in the fire risk to vegetation species susceptible to fire (fire-intolerant species).

Collaboration


Dive into the Geoffrey J. Cary's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Ian D. Davies

Australian National University

View shared research outputs
Top Co-Authors

Avatar

Robert E. Keane

United States Forest Service

View shared research outputs
Top Co-Authors

Avatar

A. Malcolm Gill

Australian National University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Richard J. Williams

Commonwealth Scientific and Industrial Research Organisation

View shared research outputs
Top Co-Authors

Avatar

David B. Lindenmayer

Australian National University

View shared research outputs
Top Co-Authors

Avatar

Karen J. King

Australian National University

View shared research outputs
Top Co-Authors

Avatar

Sam C. Banks

Australian National University

View shared research outputs
Top Co-Authors

Avatar

Owen F. Price

University of Wollongong

View shared research outputs
Researchain Logo
Decentralizing Knowledge