Mapping prescribed fire severity in south-east Australian eucalypt forests using modelling and satellite imagery: a case study

Accurate fire severity maps are fundamental to the management of flammable landscapes. Severity mapping methods have been developed and tested for wildfire, but need further refinement for prescribed fire. We evaluated the accuracy of two severity mapping methods for a low-intensity, patchy prescribed fire in a south-eastern Australian eucalypt forest: (1) the Normalised Difference Vegetation Index (NDVI) derived from RapidEye satellite imagery, and (2) PHOENIX RapidFire, a fire-spread simulation model. We used each method to generate a fire severity map (four-category: unburnt, low, moderate and severe), and then validated the maps against field-based data. We used error matrices and the Kappa statistic to assess mapping accuracy. Overall, the satellite-based map was more accurate (75%; Kappa±95% confidence interval 0.54±0.06) than the modelled map (67%; Kappa 0.40±0.06). Both methods overestimated the area of unburnt forest; however, the satellite-based map better represented moderately burnt areas. Satellite- and model-based methods both provide viable approaches for mapping prescribed fire severity, but refinements could further improve map accuracy. Appropriate severity mapping methods are essential given the increasing use of prescribed fire as a forest management tool.

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Fire severity and ecosystem resilience – lessons from the Wombat Fire Effects Study (1984-2003)

Proceedings of the Royal Society of Victoria ◽

10.1071/rs12030 ◽

2012 ◽

Vol 124 (1) ◽

pp. 30

Author(s):

Kevin G. Tolhurst

Keyword(s):

Prescribed Fire ◽

Fire Severity ◽

Fire Effects ◽

Royal Commission ◽

Mixed Species ◽

Terrestrial Mammals ◽

Low Intensity ◽

Eucalypt Forest ◽

Fire Characteristics ◽

Understorey Plants

The Wombat Fire Effects Study was established to address a number of questions in relation to the effects of repeated low-intensity fires in mixed species eucalypt forest in the foothills of Victoria. This study has now been going for 25 years and has included the study of understorey plants, fuels, bats, terrestrial mammals, reptiles, invertebrates, fungi, birds, soils, tree growth, fire behaviour and weather. This forest system has shown a high resilience to fire that is attributed here to the patchiness and variability in the fire characteristics within a fire and the relatively small proportion of the landscape being affected. A means of comparing the level of “injury” caused by low-intensity prescribed fire with high intensity wildfire is proposed so that the debate about leverage benefits (the reduction in wildfire area compared to the area of planned burning) can be more rational. There are some significant implications for assessing the relative environmental impacts of wildfire compared with the planned burning program being implemented in Victoria since the Victorian Bushfires Royal Commission recommendations (Teague et al. 2010).

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Project Vesta: Fire in Dry Eucalypt Forest

10.1071/9780643101296 ◽

2008 ◽

Cited By ~ 29

Author(s):

JS Gould ◽

WL McCaw ◽

NP Cheney ◽

PF Ellis ◽

IK Knight ◽

...

Keyword(s):

Wind Speed ◽

Fire Spread ◽

Fire Behaviour ◽

Understorey Vegetation ◽

Eucalypt Forest ◽

Age Related ◽

Vegetation Structures ◽

Eucalypt Forests ◽

The Relationship ◽

New Algorithms

Project Vesta was a comprehensive research project to investigate the behaviour and spread of high-intensity bushfires in dry eucalypt forests with different fuel ages and understorey vegetation structures. The project was designed to quantify age-related changes in fuel attributes and fire behaviour in dry eucalypt forests typical of southern Australia. The four main scientific aims of Project Vesta were: To quantify the changes in the behaviour of fire in dry eucalypt forest as fuel develops with age (i.e. time since fire); To characterise wind speed profiles in forest with different overstorey and understorey vegetation structure in relation to fire behaviour; To develop new algorithms describing the relationship between fire spread and wind speed, and fire spread and fuel characteristics including load, structure and height; and to develop a National Fire Behaviour Prediction System for dry eucalypt forests. These aims have been addressed through a program of experimental burning and associated studies at two sites in the south-west of Western Australia.

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Propensities of Old Growth, Mature and Regrowth Wet Eucalypt Forest, and Eucalyptus nitens Plantation, to Burn During Wildfire and Suffer Fire-Induced Crown Death

Fire ◽

10.3390/fire3020013 ◽

2020 ◽

Vol 3 (2) ◽

pp. 13 ◽

Cited By ~ 3

Author(s):

Suyanti Winoto-Lewin ◽

Jennifer Sanger ◽

James Kirkpatrick

Keyword(s):

Fire Severity ◽

Eucalyptus Nitens ◽

Forest Types ◽

Plantation Forest ◽

Old Growth ◽

Eucalypt Forest ◽

Old Growth Forest ◽

Eucalypt Forests ◽

Fire Incidence ◽

Topographic Variation

There are conflicting conclusions on how the flammability of wet eucalypt forests changes in the time after disturbances such as logging or wildfire. Some conclude that forests are most flammable in the decades following disturbance, while others conclude that disturbance has no effect on flammability. The comparative flammability of Eucalyptus nitens plantations in the same environment as wet eucalypt forest is not known. We determined fire incidence and fire severity in regrowth, mature and old growth wet eucalypt forest, and E. nitens plantation, in the Huon Valley, Tasmania after the January–February 2019 wildfire. To control for topographic variation and fire weather, we randomly selected sites within the fire footprint, then randomly located a paired site for each in different forest types in the same topographic environment within 3 km. Each pair of sites was burned on the same day. Old growth forest and plantations were the least likely to burn. Old growth and mature forest exhibited scorched eucalypt crowns to a much lesser degree than regrowth forests. In a comparison of paired sites, plantation forest was less likely to burn than combined mature and old growth forests, but in all cases of detected ignition the canopy of plantation was scorched. The lower flammability of older forests, and their importance as an increasing store of carbon, suggests that a cessation of logging outside plantations might have considerable benefits.

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Crop Suitability Mapping for Rice, Cassava, and Yam in North Central Nigeria

Journal of Agricultural Science ◽

10.5539/jas.v9n1p96 ◽

2016 ◽

Vol 9 (1) ◽

pp. 96 ◽

Cited By ~ 1

Author(s):

Roland Clement Abah ◽

Brilliant Mareme Petja

Keyword(s):

Crop Yield ◽

Satellite Imagery ◽

Agricultural Development ◽

Vegetation Index ◽

Policy Makers ◽

Rural Economic Development ◽

Crop Suitability ◽

Normalised Difference Vegetation Index ◽

Development Data ◽

Elevation Model

<p>Agricultural production has contributed over time to food security and rural economic development in developing countries particularly supporting the countryside. Evidence of crop yield decline exist in the Lower River Benue Basin. This was a crop suitability mapping for rice, cassava, and yam to guide policy makers in strategic planning for sustainable agricultural development. Data was collected on various themes including climate, drainage, soil, satellite imagery, and maps. Remote Sensing was used to analyse satellite imagery to produce a digital elevation model, land use and land cover map, and normalised difference vegetation index map. GIS was used to produce thematic maps, weighted percentages of attribute data, and to produce crop suitability maps through weighted overlay. Soils in the study area require fertility enhancement with inorganic fertilisers for better crop yield. Soils in the Lower River Benue Basin are suitable for yam, cassava, and rice cultivation on maps of suitable areas. Some areas were found to be highly suitable for the cultivation of rice (34.22%), cassava (17.08%) and yam (16.08%). Some other areas were found to be moderately suitable for the cultivation of cassava (48.18%), rice (45.46%), and yam (48.85%). Areas with low suitability were 14.99% (rice), 33.68% (cassava), and 29.57% (yam). This study has demonstrated the importance of crop suitability mapping and recommends that farmers’ cooperative societies and policy makers utilise the information presented to improve decision making methods and policies for agricultural development.</p>

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Estimation and monitoring of aboveground carbon stocks using spatial technology

South African Journal of Science ◽

10.17159/sajs.2015/20140170 ◽

2015 ◽

Vol 111 (9/10) ◽

Author(s):

Adolph Nyamugama ◽

Vincent Kakembo

Keyword(s):

Regression Model ◽

Satellite Imagery ◽

Geographical Information Systems ◽

Vegetation Index ◽

Anthropogenic Activities ◽

Temporal Changes ◽

Geographical Information ◽

Aboveground Carbon ◽

Normalised Difference Vegetation Index ◽

Spot 5

Monitoring temporal changes of aboveground carbon (AGC) stocks distribution in subtropical thicket is key to understanding the role of vegetation in carbon sequestration. The main objectives of this research paper were to model and quantify the temporal changes of AGC stocks between 1972 and 2010 in the Great Fish River Nature Reserve and its environs, Eastern Cape Province, South Africa. We used a method based on the integration of remote sensing and geographical information systems to estimate AGC stocks in a time series framework. A non-linear regression model was developed using Normalised Difference Vegetation Index values generated from SPOT 5 High Resolution Geometric satellite imagery of 2010 as an independent variable and AGC stock estimates from field plots as the dependent variable. The regression model was used to estimate AGC stocks from satellite imagery for 1972 (Landsat TM), 1982 (Landsat 4 TM), 1992 (Landsat 7 ETM), 2002 (Landsat ETM+) and 2010 (SPOT 5) satellite imagery. AGC stocks for the respective years were compared by means of change detection analysis at the subtropical thicket class level. The results showed a decline of AGC stocks in all the classes from 1972 to 2010. Degraded and transformed thicket classes had the highest AGC stock losses. The decline of AGC stocks was attributed to thicket transformation and degradation, which were attributed to anthropogenic activities.

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The post-fire measurement of fire severity and intensity in the Christmas 2001 Sydney wildfires

International Journal of Wildland Fire ◽

10.1071/wf03041 ◽

2004 ◽

Vol 13 (2) ◽

pp. 227 ◽

Cited By ~ 117

Author(s):

Chris J. Chafer ◽

Mark Noonan ◽

Eloys Macnaught

Keyword(s):

Vegetation Index ◽

Fire Severity ◽

Energy Levels ◽

Satellite Image ◽

Visual Assessment ◽

Fuel Load ◽

Fire Intensity ◽

Simple Method ◽

Affected Area ◽

Normalised Difference Vegetation Index

Using pre- and post-fire satellite imagery from SPOT2, we examined the fire severity and intensity of the Christmas 2001 wildfires in the greater Sydney Basin, Australia. We computed a Normalised Difference Vegetation Index (NDVI) from the two satellite images captured before (November 2001) and after (January 2002) the wildfires, then subtracted the later from the former to produce a difference image (NDVIdiff) which was subsequently classified into six fire severity classes (unburnt, low, moderate, high, very high and extreme severity). We then tested the fire severity classification on 342 sample sites within the 225 000ha fire affected area using a qualitative visual assessment guide. We found that the NDVIdiff classification produced an accuracy of at least 88% (K hat = 0.86), with the greatest discrepancy being between the low and moderate classification. Knowledge of rate of spread over some of the affected area, coupled with a complete knowledge of fuel loads, was used to retrospectively model fire intensity, which in areas of extreme fire intensity, produced heat energy levels exceeding 70 000 kW m–1. Importantly, we found no positive effect of topography on fire severity, in fact finding an inverse relationship between slope and fire severity and no effect due to aspect. Further analysis showed that flat to moderate slopes less than 18° across all aspects suffered the greatest vegetal destruction, and there was no relationship between north-westerly aspects and fire severity. We also introduce a relatively simple method for estimating fuel load biomass using a combination of satellite image and rapid field assessment. We found 79% accuracy for this method based on 125 sample sites. It is postulated that this type of analysis can greatly improve our understanding of the spatial impact of fire, how natural areas within the fire ground were impacted, and how remote sensing and GIS technologies can be efficiently used in fire management planning and post-fire analysis.

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The Effect of Antecedent Fire Severity on Reburn Severity and Fuel Structure in a Resprouting Eucalypt Forest in Victoria, Australia

Forests ◽

10.3390/f12040450 ◽

2021 ◽

Vol 12 (4) ◽

pp. 450

Author(s):

Luke Collins ◽

Adele Hunter ◽

Sarah McColl-Gausden ◽

Trent D. Penman ◽

Philip Zylstra

Keyword(s):

Seedling Recruitment ◽

Fire Severity ◽

Fire Weather ◽

Canopy Layer ◽

Eucalypt Forest ◽

Crown Scorch ◽

Eastern Australia ◽

Eucalypt Forests ◽

High Level

Research highlights—Feedbacks between fire severity, vegetation structure and ecosystem flammability are understudied in highly fire-tolerant forests that are dominated by epicormic resprouters. We examined the relationships between the severity of two overlapping fires in a resprouting eucalypt forest and the subsequent effect of fire severity on fuel structure. We found that the likelihood of a canopy fire was the highest in areas that had previously been exposed to a high level of canopy scorch or consumption. Fuel structure was sensitive to the time since the previous canopy fire, but not the number of canopy fires. Background and Objectives—Feedbacks between fire and vegetation may constrain or amplify the effect of climate change on future wildfire behaviour. Such feedbacks have been poorly studied in forests dominated by highly fire-tolerant epicormic resprouters. Here, we conducted a case study based on two overlapping fires within a eucalypt forest that was dominated by epicormic resprouters to examine (1) whether past wildfire severity affects future wildfire severity, and (2) how combinations of understorey fire and canopy fire within reburnt areas affect fuel properties. Materials and Methods—The study focused on ≈77,000 ha of forest in south-eastern Australia that was burnt by a wildfire in 2007 and reburnt in 2013. The study system was dominated by eucalyptus trees that can resprout epicormically following fires that substantially scorch or consume foliage in the canopy layer. We used satellite-derived mapping to assess whether the severity of the 2013 fire was affected by the severity of the 2007 fire. Five levels of fire severity were considered (lowest to highest): unburnt, low canopy scorch, moderate canopy scorch, high canopy scorch and canopy consumption. Field surveys were then used to assess whether combinations of understorey fire (<80% canopy scorch) and canopy fire (>90% canopy consumption) recorded over the 2007 and 2013 fires caused differences in fuel structure. Results—Reburn severity was influenced by antecedent fire severity under severe fire weather, with the likelihood of canopy-consuming fire increasing with increasing antecedent fire severity up to those classes causing a high degree of canopy disturbance (i.e., high canopy scorch or canopy consumption). The increased occurrence of canopy-consuming fire largely came at the expense of the moderate and high canopy scorch classes, suggesting that there was a shift from crown scorch to crown consumption. Antecedent fire severity had little effect on the severity patterns of the 2013 fire under nonsevere fire weather. Areas affected by canopy fire in 2007 and/or 2013 had greater vertical connectivity of fuels than sites that were reburnt by understorey fires, though we found no evidence that repeated canopy fires were having compounding effects on fuel structure. Conclusions—Our case study suggests that exposure to canopy-defoliating fires has the potential to increase the severity of subsequent fires in resprouting eucalypt forests in the short term. We propose that the increased vertical connectivity of fuels caused by resprouting and seedling recruitment were responsible for the elevated fire severity. The effect of antecedent fire severity on reburn severity will likely be constrained by a range of factors, such as fire weather.

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Tree Mortality following Prescribed Fire and a Storm Surge Event in Slash Pine (Pinus elliottiivar.densa) Forests in the Florida Keys, USA

International Journal of Forestry Research ◽

10.1155/2010/204795 ◽

2010 ◽

Vol 2010 ◽

pp. 1-13 ◽

Cited By ~ 10

Author(s):

Jay P. Sah ◽

Michael S. Ross ◽

James R. Snyder ◽

Danielle E. Ogurcak

Keyword(s):

Storm Surge ◽

Prescribed Fire ◽

Statistical Power ◽

Tree Mortality ◽

Prescribed Burning ◽

Fire Severity ◽

Practical Importance ◽

Florida Keys ◽

Management Tool ◽

Individual Tree

In fire-dependent forests, managers are interested in predicting the consequences of prescribed burning on postfire tree mortality. We examined the effects of prescribed fire on tree mortality in Florida Keys pine forests, using a factorial design with understory type, season, and year of burn as factors. We also used logistic regression to model the effects of burn season, fire severity, and tree dimensions on individual tree mortality. Despite limited statistical power due to problems in carrying out the full suite of planned experimental burns, associations with tree and fire variables were observed. Post-fire pine tree mortality was negatively correlated with tree size and positively correlated with char height and percent crown scorch. Unlike post-fire mortality, tree mortality associated with storm surge from Hurricane Wilma was greater in the large size classes. Due to their influence on population structure and fuel dynamics, the size-selective mortality patterns following fire and storm surge have practical importance for using fire as a management tool in Florida Keys pinelands in the future, particularly when the threats to their continued existence from tropical storms and sea level rise are expected to increase.

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A New Application of the Disturbance Index for Fire Severity in Coastal Dunes

Remote Sensing ◽

10.3390/rs13234739 ◽

2021 ◽

Vol 13 (23) ◽

pp. 4739

Author(s):

Marcio D. DaSilva ◽

David Bruce ◽

Patrick A. Hesp ◽

Graziela Miot da Silva

Keyword(s):

Vegetation Index ◽

Fire Severity ◽

Coastal Dune ◽

Burn Severity ◽

Soil Conditions ◽

Initiation Mechanism ◽

Disturbance Index ◽

Dune Systems ◽

Normalised Difference Vegetation Index ◽

Vegetation Loss

Fires are a disturbance that can lead to short term dune destabilisation and have been suggested to be an initiation mechanism of a transgressive dune phase when paired with changing climatic conditions. Fire severity is one potential factor that could explain subsequent coastal dune destabilisations, but contemporary evidence of destabilisation following fire is lacking. In addition, the suitability of conventional satellite Earth Observation methods to detect the impacts of fire and the relative fire severity in coastal dune environments is in question. Widely applied satellite-derived burn indices (Normalised Burn Index and Normalised Difference Vegetation Index) have been suggested to underestimate the effects of fire in heterogenous landscapes or areas with sparse vegetation cover. This work assesses burn severity from high resolution aerial and Sentinel 2 satellite imagery following the 2019/2020 Black Summer fires on Kangaroo Island in South Australia, to assess the efficacy of commonly used satellite indices, and validate a new method for assessing fire severity in coastal dune systems. The results presented here show that the widely applied burn indices derived from NBR differentially assess vegetation loss and fire severity when compared in discrete soil groups across a landscape that experienced a very high severity fire. A new application of the Tasselled Cap Transformation (TCT) and Disturbance Index (DI) is presented. The differenced Disturbance Index (dDI) improves the estimation of burn severity, relative vegetation loss, and minimises the effects of differing soil conditions in the highly heterogenous landscape of Kangaroo Island. Results suggest that this new application of TCT is better suited to diverse environments like Mediterranean and semi-arid coastal regions than existing indices and can be used to better assess the effects of fire and potential remobilisation of coastal dune systems.

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Bats and fire: a global review

Fire Ecology ◽

10.1186/s42408-021-00109-0 ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Susan C. Loeb ◽

Rachel V. Blakey

Keyword(s):

Climate Change ◽

South America ◽

Prescribed Fire ◽

Fire Severity ◽

Fire Effects ◽

Fire Frequency ◽

Management Tool ◽

Additional Stress ◽

Lack Of Information ◽

Season Of Burn

Abstract Background Bats are important components of forested ecosystems and are found in forests worldwide. Consequently, they often interact with fire. Previous reviews of the effects of fire on bats have focused on prescribed fire effects, in part due to the limited number of studies on bat responses to wildfire. However, over the past several years, studies on bat responses to wildfire and prescribed fire have increased considerably. We reviewed this rapidly expanding body of literature to determine whether bats respond differently to prescribed fire and wildfire, and the important factors driving those differences. We also examined regional similarities and differences in bat response to prescribed fire and wildfire and identified areas in need of further research. Results Our review included 52 studies (29 prescribed fire, 23 wildfire) from North and South America, Europe, Australia, and Africa, although studies from Europe, South America, and Africa were limited. In general, we found that bats show positive or neutral responses to prescribed fire, whereas a greater proportion of negative responses were reported for wildfire. However, some of the negative responses to wildfire are short-lived or local, suggesting that bats may be resilient to the effects of fire. Factors such as fire severity, fire frequency, time since last burn, burn extent, season of burn, and pyrodiversity were all found to be important drivers of bats’ responses to both prescribed fire and wildfire. Conclusions The importance of the spatial and temporal aspects of fire suggests that these factors need to be considered when designing future studies and interpreting results. Pyrodiversity may be a particularly important concept to further our understanding of bats’ responses to fire. We found several gaps in our knowledge including lack of information on direct effects of fire (e.g., mortality), regional and taxonomic biases, effects of wildfire on roosting habitat, and the effects of climate change. Although current studies suggest that fire may be an important management tool for improving bat habitat, the threat of more frequent, extensive, and severe wildfires may put additional stress on some bat populations, particularly those being impacted by disease, habitat loss and fragmentation, and climate change.

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