Delivering effective savanna fire management for defined biodiversity conservation outcomes: an Arnhem Land case study

2020 ◽  
Vol 29 (5) ◽  
pp. 386 ◽  
Author(s):  
Jay Evans ◽  
Jeremy Russell-Smith
Keyword(s):  
Prescribed Burning ◽  
Fire Management ◽  
Fire Regime ◽  
Dry Season ◽  
Prescribed Burns ◽  
Active Fire ◽  
Arnhem Land ◽  
Ecological Threshold ◽  
History Of ◽  
In Fire

Given the recent history of frequent and extensive late dry season wildfire in Australia’s fire-prone northern savannas, regional conservation-based fire management programs typically aim to mitigate wildfire through the use of strategic prescribed burning during the cooler early dry season. However, it remains unclear as to the extent such environmental management concerns are being addressed by these renewed fire management efforts. This study documents changes in fire regime in the western Arnhem Land region of northern Australia associated with the implementation of active fire management since 2006. Over a 12-year period, the regional fire regime has transitioned from late dry season, wildfire-dominated to being characterised by a majority of fires occurring as small early dry season prescribed burns. Although overall area burnt has not significantly decreased, most ecological threshold metrics have improved, with the exception of those describing the maintenance of longer-unburnt habitat. Challenges involved with defining, delivering, monitoring and evaluating heterogeneity targets are discussed.

scholarly journals Regional seasonality of fire size and fire weather conditions across Australia's northern savanna

2020 ◽  
Vol 29 (1) ◽  
pp. 1 ◽  
Author(s):  
Justin J. Perry ◽  
Garry D. Cook ◽  
Erin Graham ◽  
C. P. (Mick) Meyer ◽  
Helen T. Murphy ◽  
...  
Keyword(s):  
Prescribed Burning ◽  
Fire Regime ◽  
Weather Conditions ◽  
Temporal Variations ◽  
Dry Season ◽  
Fire Weather ◽  
Fire Size ◽  
Spatial Consistency ◽  
In Fire ◽  
Extreme Fire

Australia’s northern savannas have among the highest fire frequencies in the world. The climate is monsoonal, with a long, dry season of up to 9 months, during which most fires occur. The Australian Government’s Emissions Reduction Fund allows land managers to generate carbon credits by abating the direct emissions of CO2 equivalent gases via prescribed burning that shifts the fire regime from predominantly large, high-intensity late dry season fires to a more benign, early dry season fire regime. However, the Australian savannas are vast and there is significant variation in weather conditions and seasonality, which is likely to result in spatial and temporal variations in the commencement and length of late dry season conditions. Here, we assess the temporal and spatial consistency of the commencement of late dry season conditions, defined as those months that maximise fire size and where the most extreme fire weather conditions exist. The results demonstrate that significant yearly, seasonal and spatial variations in fire size and fire weather conditions exist, both within and between bioregions. The effective start of late dry season conditions, as defined by those months that maximise fire size and where the most extreme fire weather variables exist, is variable across the savannas.

Efficacy of permanent firebreaks and aerial prescribed burning in western Arnhem Land, Northern Territory, Australia

2007 ◽  
Vol 16 (3) ◽  
pp. 295 ◽  
Author(s):  
Owen F. Price ◽  
Andrew C. Edwards ◽  
Jeremy Russell-Smith
Keyword(s):  
Prescribed Burning ◽  
Fire Management ◽  
Fire Frequency ◽  
Northern Territory ◽  
Dry Season ◽  
Stream Order ◽  
Arnhem Land ◽  
Linear Modelling ◽  
Populated Region ◽  
Generalised Linear Modelling

We investigated the efficacy of firebreaks in the prevention of wildfires in the Arnhem Land Plateau, a vast, rugged and sparsely populated region with high biodiversity value and frequent wildfires. A total of 623 events where a fire met a permanent firebreak (cliffs, stream order, tracks and roads) in different fire seasons were compiled. Cliffs were more effective than streams at stopping fires, which were more effective than roads. Larger streams were more effective than small ones. The largest streams stop 75% of early dry season fires, but there are no firebreak types with more than 50% likelihood of stopping a late dry season fire. Geographic Information System (GIS) surfaces of the relative density of the three firebreak features in the landscape were randomly sampled and compared with the total number of fires and late dry season fires using generalised linear modelling. Several of the density variables were weakly but significantly related to fire frequency, and it appears that late dry season fires are influenced by features at a larger scale (16-km radius) than total fires (4 km). The Aerial Prescribed Burning program for 2004 was studied to identify how effective it was at stopping subsequent wildfires by dividing ignition lines into 137 5-km sections. Only 20% of sections achieved a 100% burn and where gaps occurred, a subsequent fire was 88% likely to penetrate the line. Firebreaks are not certain instruments for fire management in this area.

Contemporary fire regime risks to key ecological assets and processes in north Australian savannas

2015 ◽  
Vol 24 (6) ◽  
pp. 857 ◽  
Author(s):  
Andrew Edwards ◽  
Jeremy Russell-Smith ◽  
Mick Meyer
Keyword(s):  
Climate Change ◽  
Prescribed Burning ◽  
Fire Management ◽  
Fire Regime ◽  
Ghg Emissions ◽  
Fire Regimes ◽  
Dry Season ◽  
Suspended Sediment Transport ◽  
Change Models ◽  
Positive Effects

Despite the intact appearance of relatively unmodified north Australian savannas, mounting evidence indicates that contemporary fire regimes characterised by frequent, extensive and severe late dry season wildfires are having deleterious effects on a range of regional water, soil erosion, biodiversity conservation and greenhouse gas (GHG) emissions values. For the high rainfall (>1000 mm year–1) savannas (426 000 km2), we assessed the spatial effects of contemporary fire regimes within the context of ecosystem response models and three plausible alternative fire management scenarios on ecosystem attributes. Over the 2008–12 assessment period, mean annual fire frequency (0.53) comprised mostly late dry season fires. Although spatially variable, contemporary fire regimes resulted in substantial GHG emissions, hill slope erosion and suspended sediment transport, a slight decline in carbon biomass and slight positive effects on fire-vulnerable vegetation. Based on available climate change models and strategic fire management practice, we show that, relative to business-as-usual, improved fire management involving strategic prescribed burning results in substantial benefits to most ecosystem attributes, including under enhanced climate change conditions, whereas in the absence of improved fire management, climate change results in substantially worse outcomes.

scholarly journals Prescribed burning in a mediterranean-climate region mitigates the disturbance by bushfire to a critical food resource for an endangered bird, the Carnaby’s cockatoo

Fire Ecology ◽  
2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Valerie S. Densmore ◽  
Emma S. Clingan
Keyword(s):  
Seed Production ◽  
Prescribed Burning ◽  
Fire Regime ◽  
Fire Hazard ◽  
Food Resource ◽  
Management Tool ◽  
Fire Intensity ◽  
Prescribed Burns ◽  
Low Intensity ◽  
Percentage Survival

Abstract Background Prescribed burning is used to reduce fire hazard in highly flammable vegetation types, including Banksia L.f. woodland that occurs on the Swan Coastal Plain (SCP), Western Australia, Australia. The 2016 census recorded well over 1.9 million people living on the SCP, which also encompasses Perth, the fourth largest city in Australia. Banksia woodland is prone to frequent ignitions that can cause extensive bushfires that consume canopy-stored banksia seeds, a critical food resource for an endangered bird, the Carnaby’s cockatoo (Calyptorynchus latirostris, Carnaby 1948). The time needed for banksias to reach maturity and maximum seed production is several years longer than the typical interval between prescribed burns. We compared prescribed burns to bushfires and unburned sites at three locations in banksia woodland to determine whether low-intensity prescribed burns affect the number of adult banksias and their seed production. Study sites were matched to the same vegetation complex, fire regime, and time-since-fire to isolate fire intensity as a variable. Results Headfire rates of spread and differenced normalized burn ratios indicated that prescribed burning was generally of a much lower intensity than bushfire. The percentage survival of adult banksias and their production of cones and follicles (seeds) did not decrease during the first three years following a prescribed burn. However, survival and seed production were significantly diminished followed high-intensity bushfire. Thus, carrying capacity for Carnaby’s cockatoo was unchanged by prescribed burning but decreased markedly following bushfire in banksia woodland. Conclusions These results suggest that prescribed burning is markedly different from bushfire when considering appropriate fire intervals to conserve canopy habitats in fire-resilient vegetation communities. Therefore, low-intensity prescribed burning represents a viable management tool to reduce the frequency and extent of bushfire impacts on banksia woodland and Carnaby’s cockatoo.

scholarly journals A reconstruction of the recent fire regimes of Majete Wildlife Reserve, Malawi, using remote sensing

Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Willem A. Nieman ◽  
Brian W. van Wilgen ◽  
Alison J. Leslie
Keyword(s):  
Remote Sensing ◽  
Fire Management ◽  
Fire Regime ◽  
Fire Regimes ◽  
Dry Season ◽  
Annual Rainfall ◽  
Vegetation Types ◽  
Local Evidence ◽  
Hot Dry Season ◽  
Wildlife Reserve

Abstract Background Fire is an important process that shapes the structure and functioning of African savanna ecosystems, and managers of savanna protected areas use fire to achieve ecosystem goals. Developing appropriate fire management policies should be based on an understanding of the determinants, features, and effects of prevailing fire regimes, but this information is rarely available. In this study, we report on the use of remote sensing to develop a spatially explicit dataset on past fire regimes in Majete Wildlife Reserve, Malawi, between 2001 and 2019. Moderate Resolution Imaging Spectroradiometer (MODIS) images were used to evaluate the recent fire regime for two distinct vegetation types in Majete Wildlife Reserve, namely savanna and miombo. Additionally, a comparison was made between MODIS and Visible Infrared Imager Radiometer Suite (VIIRS) images by separately evaluating selected aspects of the fire regime between 2012 and 2019. Results Mean fire return intervals were four and six years for miombo and savanna vegetation, respectively, but the distribution of fire return intervals was skewed, with a large proportion of the area burning annually or biennially, and a smaller proportion experiencing much longer fire return intervals. Variation in inter-annual rainfall also resulted in longer fire return intervals during cycles of below-average rainfall. Fires were concentrated in the hot-dry season despite a management intent to restrict burning to the cool-dry season. Mean fire intensities were generally low, but many individual fires had intensities of 14 to 18 times higher than the mean, especially in the hot-dry season. The VIIRS sensors detected many fires that were overlooked by the MODIS sensors, as images were collected at a finer scale. Conclusions Remote sensing has provided a useful basis for reconstructing the recent fire regime of Majete Wildlife Reserve, and has highlighted a current mismatch between intended fire management goals and actual trends. Managers should re-evaluate fire policies based on our findings, setting clearly defined targets for the different vegetation types and introducing flexibility to accommodate natural variation in rainfall cycles. Local evidence of the links between fires and ecological outcomes will require further research to improve fire planning.

scholarly journals The influence of prescribed fire on the extent of wildfire in savanna landscapes of western Arnhem Land, Australia

2012 ◽  
Vol 21 (3) ◽  
pp. 297 ◽  
Author(s):  
Owen F. Price ◽  
Jeremy Russell-Smith ◽  
Felicity Watt
Keyword(s):  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Prescribed Fire ◽  
Fire History ◽  
Prescribed Burning ◽  
Landsat Imagery ◽  
Fire Regimes ◽  
Dry Season ◽  
Gas Emissions ◽  
Arnhem Land

Fire regimes in many north Australian savanna regions are today characterised by frequent wildfires occurring in the latter part of the 7-month dry season. A fire management program instigated from 2005 over 24 000 km2 of biodiversity-rich Western Arnhem Land aims to reduce the area and severity of late dry-season fires, and associated greenhouse gas emissions, through targeted early dry-season prescribed burning. This study used fire history mapping derived mostly from Landsat imagery over the period 1990–2009 and statistical modelling to quantify the mitigation of late dry-season wildfire through prescribed burning. From 2005, there has been a reduction in mean annual total proportion burnt (from 38 to 30%), and particularly of late dry-season fires (from 29 to 12.5%). The slope of the relationship between the proportion of early-season prescribed fire and subsequent late dry-season wildfire was ~–1. This means that imposing prescribed early dry-season burning can substantially reduce late dry-season fire area, by direct one-to-one replacement. There is some evidence that the spatially strategic program has achieved even better mitigation than this. The observed reduction in late dry-season fire without concomitant increase in overall area burnt has important ecological and greenhouse gas emissions implications. This efficient mitigation of wildfire contrasts markedly with observations reported from temperate fire-prone forested systems.

Bayes Nets as a method for analysing the influence of management actions in fire planning

2011 ◽  
Vol 20 (8) ◽  
pp. 909 ◽  
Author(s):  
T. D. Penman ◽  
O. Price ◽  
R. A. Bradstock
Keyword(s):  
Process Model ◽  
Management Practices ◽  
Prescribed Burning ◽  
Fire Management ◽  
Relative Reduction ◽  
Holistic Model ◽  
Bayes Nets ◽  
Management Actions ◽  
Fire Planning ◽  
In Fire

Wildfire can result in significant economic costs with inquiries following such events often recommending an increase in management effort to reduce the risk of future losses. Currently, there are no objective frameworks in which to assess the relative merits of management actions or the synergistic way in which the various combinations may act. We examine the value of Bayes Nets as a method for assessing the risk reduction from fire management practices using a case study from a forested landscape. Specifically, we consider the relative reduction in wildfire risk from investing in prescribed burning, initial or rapid attack and suppression. The Bayes Net was developed using existing datasets, a process model and expert opinion. We compared the results of the models with the recorded fire data for an 11-year period from 1997 to 2000 with the model successfully duplicating these data. Initial attack and suppression effort had the greatest effect on the distribution of the fire sizes for a season. Bayes Nets provide a holistic model for considering the effect of multiple fire management methods on the risk of wildfires. The methods could be further advanced by including the costs of management and conducting a formal decision analysis.

Ecological thresholds and the status of fire-sensitive vegetation in western Arnhem Land, northern Australia: implications for management

2009 ◽  
Vol 18 (2) ◽  
pp. 127 ◽  
Author(s):  
Andrew C. Edwards ◽  
Jeremy Russell-Smith
Keyword(s):  
National Parks ◽  
Fire History ◽  
Fire Management ◽  
Fire Regime ◽  
Vegetation Types ◽  
Northern Australia ◽  
Study Region ◽  
Ecological Thresholds ◽  
Arnhem Land ◽  
The Status

The paper examines the application of the ecological thresholds concept to fire management issues concerning fire-sensitive vegetation types associated with the remote, biodiversity-rich, sandstone Arnhem Plateau, in western Arnhem Land, monsoonal northern Australia. In the absence of detailed assessments of fire regime impacts on component biota such as exist for adjoining Nitmiluk and World Heritage Kakadu National Parks, the paper builds on validated 16-year fire history and vegetation structural mapping products derived principally from Landsat-scale imagery, to apply critical ecological thresholds criteria as defined by fire regime parameters for assessing the status of fire-sensitive habitat and species elements. Assembled data indicate that the 24 000 km2 study region today experiences fire regimes characterised generally by high annual frequencies (mean = 36.6%) of large (>10 km2) fires that occur mostly in the late dry season under severe fire-weather conditions. Collectively, such conditions substantially exceed defined ecological thresholds for significant proportions of fire-sensitive indicator rain forest and heath vegetation types, and the long-lived obligate seeder conifer tree species, Callitris intratropica. Thresholds criteria are recognised as an effective tool for informing ecological fire management in a variety of geographic settings.

scholarly journals Historical fire records at the two ends of Iberian Central Mountain System: Estrela massif and Ayllón massif

2019 ◽  
pp. 31
Author(s):  
Catarina Romão Sequeira ◽  
Cristina Montiel-Molina ◽  
Francisco Castro Rego
Keyword(s):  
Fire Regime ◽  
Fire Regimes ◽  
Historical Record ◽  
Multiscale Approach ◽  
Natural Region ◽  
Fire Use ◽  
Prone Area ◽  
Mountain System ◽  
History Of ◽  
In Fire

The Iberian Peninsula has a long history of fire, as the Central Mountain System, from the Estrela massif in Portugal to the Ayllón massif in Spain, is a major fire-prone area. Despite being part of the same natural region, there are different environmental, political and socio-economic contexts at either end, which might have led to distinct human causes of wildfires and associated fire regimes. The hypothesis for this research lies in the historical long-term relationship between wildfire risks and fire use practices within a context of landscape dynamics. In addition to conducting an analysis of the statistical period, a spatial and temporal multiscale approach was taken by reconstructing the historical record of prestatistical fires and land management history at both ends of the Central Mountain System. The main result is the different structural causes of wildland fires at either end of the Central Mountain System, with human factors being more important than environmental factors in determining the fire regimes in both contexts. The study shows that the development of the fire regime was non-linear in the nineteenth and twentieth centuries, due to broader local human context factors which led to a shift in fire-use practices.

scholarly journals Postglacial Fire Frequency and its Relation to Long-Term Vegetational and Climatic Changes in Yellowstone Park

1992 ◽  
Vol 16 ◽  
pp. 212-218
Author(s):  
Cathy Whitlock
Keyword(s):  
Fire Regime ◽  
Fire Frequency ◽  
Northern Rocky Mountains ◽  
Modern Pollen ◽  
Pollen Rain ◽  
History Of ◽  
Fossil Records ◽  
In Fire ◽  
The Relationship

The primary research objective has been to study the vegetational history of Yellowstone and its sensitivity to changes in climate and fire frequency. To establish a sequence of vegetational changes, a network of pollen records spanning the last 14,000 years has been studied from different types of vegetation within the Park. The relationship between modern pollen rain, modern vegetation and present­day climate in the northern Rocky Mountains has been the basis for interpreting past vegetation and climate from the fossil records. Changes in fire regime during the past 14,000 years have been inferred from sedimentary charcoal and other fire proxy in lake sediments. Calibration of the fire signal is based on a study that measures the input of charcoal into lakes following the 1988 fires in Yellowstone.

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