The extraordinary 2019/20 Australian bushfire season: contributing processes and environmental impacts

2020 ◽  
Author(s):  
Albert van Dijk ◽  
Marta Yebra
Keyword(s):  
Fire Suppression ◽  
Fire Severity ◽  
Critical Factor ◽  
Fuel Load ◽  
Fire Season ◽  
Native Forest ◽  
Environmental Consequences ◽  
Eastern Australia ◽  
Ability To Regenerate ◽  
History Of

<p>The recent Australian summer witnessed bushfire at a scale that is without historical precedent. We analysed the scale and severity of the fires, the main processes contributing to their scale, and environmental consequences that have already become apparent.  We did this by combining satellite-derived information of vegetation cover, biomass and history, of soil and vegetation moisture content, and of fire extent and severity. More than 80,000 km2 was burnt, much of it native forest. Fire severity varied, but was overall greater than in preceding years. A critical factor contributing to fire conditions was a multi-year drought in Eastern Australia, which culminated in 2019 with the hottest and driest year in more than a century. During the fire season, fire danger conditions were further exacerbated by oceanic modes in the Indian and Southern Oceans, which limited circulation and caused excessive heating of the Australian land mass. Fuel availability in forests was unusually high. Reasons for this were several, including afforestation and regrowth as well as effective fire suppression in preceding years, while a contributing role for CO<sub>2</sub> fertilisation is also plausible. Combined with the drought and associated vegetation mortality, this created a high and flammable fuel load. The fires strongly affected Australia’s total living carbon pool, which was already depleted by several years of below-average rainfall. Greenhouse gas releases associated with drought and bushfires are not considered in official emission accounts, but are of comparable magnitude. The smoke emissions also caused direct health impacts, affecting cities like Sydney, Melbourne and Canberra for prolonged periods. Most of the burnt forests are resilient to fire and will regenerate, assuming rainfall conditions improve. The severity, scale and connectedness of some of the fire complexes suggest ecological recolonization may be very slow, while a number of threatened species may not recover. Perhaps most concerning, some of the forests affected had burnt only years before, whereas other areas contained vegetation communities not experiencing fire for centuries, raising questions about their ability to regenerate and possibly permanent ecological regime shifts.</p>

scholarly journals Short-term impact of a mega-fire on small mammal communities during prolonged drought

2012 ◽  
Vol 124 (1) ◽  
pp. 61 ◽  
Author(s):  
Mike Stevens ◽  
John White ◽  
Raylene Cooke
Keyword(s):  
Small Mammal ◽  
Prescribed Burning ◽  
Fire Suppression ◽  
Fire Severity ◽  
Mammal Species ◽  
Management Actions ◽  
Conservation Implications ◽  
Eastern Australia ◽  
Significant Life ◽  
The Impact

Increased size, severity and frequency of wildfire is predicted as a consequence of prolonged droughts associated with climate change. In south-eastern Australia severe landscape-scale wildfires (mega-fires) have elicited a strong anthropocentric response due to the significant life and property impacts. However, the impact of mega-fires on fauna, habitat and subsequent management actions are poorly understood. Small mammals were surveyed to examine mega-fire impact using the post-2006 wildfire landscape of the Grampians National Park, Victoria, Australia. Long-term research sites were established with 9620 trap nights completed in autumn 2008 across thirty-six sampling units. Vegetation structure, floristics, fire severity, patch size and overall fuel hazard were measured to investigate correlations with changes in small mammal abundance.Two years post-wildfire, rapid resurgence of house mouse (Mus musculus) was detected, conversely the abundance of native small mammal species was severely impacted. No sampling category within the burnt perimeter provided superior refuge presenting potential conservation implications. A habitat vacancy model is introduced where small mammal recolonisation post-wildfire depends on a lack of isolation and connectivity of populations. Floristic and structural contributions of vegetation to higher overall fuel hazard areas are essential in maintaining diverse fauna assemblages. As such, prescribed burning or fire suppression tactics such as ‘patching out’ or ‘burning out’ require consideration when contributing to further reduction of complex habitat patches following fires.

scholarly journals Two thresholds determine climatic control of forest-fire size in Europe

2012 ◽  
Vol 9 (7) ◽  
pp. 9065-9089 ◽  
Author(s):  
L. Loepfe ◽  
A. Rodrigo ◽  
F. Lloret
Keyword(s):  
Fire Suppression ◽  
Weather Conditions ◽  
Meteorological Conditions ◽  
Fuel Load ◽  
Fire Season ◽  
Annual Rainfall ◽  
Climate Change Scenarios ◽  
Fire Size ◽  
Large Fires ◽  
Fire Extent

Abstract. Fire weather indices predict fire extent from meteorological conditions assuming a monotonic function; this approach is frequently used to predict future fire patterns under climate change scenarios using linear extrapolation. However, the relationship between weather and fire extent may potentially depend on the existence of fuel humidity thresholds above which this relationship changes dramatically, challenging this statistical approach. Here we combine the continuous and the threshold approaches to analyze satellite-detected fires in Europe during 2001–2010 in relation to meteorological conditions, showing that fire size response to increasing dryness follows a ramp function, i.e. with two plateaus separated by a phase of monotonic increase. This study confirms that at a continental and a high-resolution temporal scales, large fires are very unlikely to occur under moist conditions, but it also reveals that fire size stops to be controlled by fuel humidity above a given threshold of dryness. Thus, fuel humidity control only applies when fire is not limited by other factors such as fuel load, as large fires are virtually absent in dry regions with less than 500 mm of average annual rainfall, i.e. where fuel amount is insufficient. In regions with sufficient fuel, other factors such as fire suppression or fuel discontinuity can impede large fires even under very dry weather conditions. These findings are relevant under current climatic trends in which the fire season length, in terms of number of days with DC (drought code) values above the observed thresholds (break points), is increasing in many parts of the Mediterranean, while it is decreasing in Eastern Europe and remains unchanged in Central Europe.

scholarly journals Predicting wildfire impacts on the prehistoric archaeological record of the Jemez Mountains, New Mexico, USA

Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Megan M. Friggens ◽  
Rachel A. Loehman ◽  
Connie I. Constan ◽  
Rebekah R. Kneifel
Keyword(s):  
New Mexico ◽  
Fire Severity ◽  
Fire Effects ◽  
Burn Severity ◽  
Fire Season ◽  
Archaeological Sites ◽  
Archaeological Record ◽  
Human Environment ◽  
Jemez Mountains ◽  
Archaeological Materials

Abstract Background Wildfires of uncharacteristic severity, a consequence of climate changes and accumulated fuels, can cause amplified or novel impacts to archaeological resources. The archaeological record includes physical features associated with human activity; these exist within ecological landscapes and provide a unique long-term perspective on human–environment interactions. The potential for fire-caused damage to archaeological materials is of major concern because these resources are irreplaceable and non-renewable, have social or religious significance for living peoples, and are protected by an extensive body of legislation. Although previous studies have modeled ecological burn severity as a function of environmental setting and climate, the fidelity of these variables as predictors of archaeological fire effects has not been evaluated. This study, focused on prehistoric archaeological sites in a fire-prone and archaeologically rich landscape in the Jemez Mountains of New Mexico, USA, identified the environmental and climate variables that best predict observed fire severity and fire effects to archaeological features and artifacts. Results Machine learning models (Random Forest) indicate that topography and variables related to pre-fire weather and fuel condition are important predictors of fire effects and severity at archaeological sites. Fire effects were more likely to be present when fire-season weather was warmer and drier than average and within sites located in sloped, treed settings. Topographic predictors were highly important for distinguishing unburned, moderate, and high site burn severity as classified in post-fire archaeological assessments. High-severity impacts were more likely at archaeological sites with southern orientation or on warmer, steeper, slopes with less accumulated surface moisture, likely associated with lower fuel moistures and high potential for spreading fire. Conclusions Models for predicting where and when fires may negatively affect the archaeological record can be used to prioritize fuel treatments, inform fire management plans, and guide post-fire rehabilitation efforts, thus aiding in cultural resource preservation.

Spatial and temporal variations of fire regimes in the Canadian Rocky Mountains and Foothills of southern Alberta

2016 ◽  
Vol 25 (11) ◽  
pp. 1117 ◽  
Author(s):  
Marie-Pierre Rogeau ◽  
Mike D. Flannigan ◽  
Brad C. Hawkes ◽  
Marc-André Parisien ◽  
Rick Arthur
Keyword(s):  
Rocky Mountains ◽  
Fire History ◽  
Fire Severity ◽  
Ecological Integrity ◽  
Fire Regimes ◽  
Temporal Variations ◽  
Fire Season ◽  
Canadian Rocky Mountains ◽  
Southern Alberta ◽  
Fire Exclusion

Like many fire-adapted ecosystems, decades of fire exclusion policy in the Rocky Mountains and Foothills natural regions of southern Alberta, Canada are raising concern over the loss of ecological integrity. Departure from historical conditions is evaluated using median fire return intervals (MdFRI) based on fire history data from the Subalpine (SUB), Montane (MT) and Upper Foothills (UF) natural subregions. Fire severity, seasonality and cause are also documented. Pre-1948 MdFRI ranged between 65 and 85 years in SUB, between 26 and 35 years in MT and was 39 years in UF. The fire exclusion era resulted in a critical departure of 197–223% in MT (MdFRI = 84–104 years). The departure in UF was 170% (MdFRI = 104 years), while regions of continuous fuels in SUB were departed by 129% (MdFRI = 149 years). The most rugged region of SUB is within its historical range of variation with a departure of 42% (MdFRI = 121 years). More mixed-severity burning took place in MT and UF. SUB and MT are in a lightning shadow pointing to a predominance of anthropogenic burning. A summer fire season prevails in SUB, but occurs from spring to fall elsewhere. These findings will assist in developing fire and forest management policies and adaptive strategies in the future.

Distribution and life history of caridean shrimps in regulated lowland rivers in southern Australia

2004 ◽  
Vol 55 (3) ◽  
pp. 295 ◽  
Author(s):  
A. J. Richardson ◽  
J. E. Growns ◽  
R. A. Cook
Keyword(s):  
Life History ◽  
Life Stages ◽  
Lowland Rivers ◽  
Flow Alteration ◽  
Eastern Australia ◽  
History Of ◽  
Paratya Australiensis ◽  
Juvenile Stages ◽  
Shrimp Abundance ◽  
Large Adult

Caridean shrimps are an integral component of lowland river ecosystems in south-eastern Australia, but their distributions may be affected by flow alteration. Monthly shrimp samples were collected from slackwaters in three hydrologically distinct sections of the heavily regulated Campaspe River and the less regulated Broken River for three consecutive years. The distributions of Paratya australiensis, Caridina mccullochi and Macrobrachium australiense, along with their life history in river sections with different hydrology are outlined. Paratya australiensis and M. australiense occurred in all sections, but C. mccullochi was absent from sections of the Campaspe River that received irrigation flows during summer/autumn. Shrimp larvae were most abundant in summer (December–February) and juvenile recruitment continued through to mid autumn (April). Breeding and recruitment of P. australiensis occurred for longer than other shrimps. Apart from large adult and berried M. australiense, all life stages of shrimps commonly occurred in slackwaters, particularly the larval and juvenile stages. Irrigation flows in summer/autumn probably adversely affect the size, extent and arrangement of slackwaters, at a time when they may be critical habitats for C. mccullochi larval development and recruitment. Dams and weirs in the Campaspe River may have influenced shrimp abundance and the timing of breeding.

Alternative Futures for Forest-Based Nanomaterials

2016 ◽  
Vol 8 (4) ◽  
pp. 197-221 ◽  
Author(s):  
David N. Bengston ◽  
Jim Dator ◽  
Michael J. Dockry ◽  
Aubrey Yee
Keyword(s):  
Forest Management ◽  
Collaborative Research ◽  
Research Agenda ◽  
Forest Products ◽  
The United States ◽  
Solar Panels ◽  
Alternative Futures ◽  
Environmental Consequences ◽  
History Of ◽  
The U.S

Forestry and forest products research has entered into a robust research agenda focused on creating nano-sized particles and nanoproducts from wood. As wood-based materials can be sustainably produced, the potential of these renewable products could be limitless and include high-end compostable electronics, paint-on solar panels, and lightweight materials for airplanes and cars. Others warn about potential serious negative health and environmental consequences. Either way, wood-based nanomaterials could disrupt forestry as we know it. This article is a summary and analysis of a collaborative research project exploring the futures of wood-based nanomaterials within the context of the futures of forests and forest management within the United States. We start by describing the history of forestry through the lens of the U.S. Forest Service, then describe nanotechnology in general and wood-based nanocellulose specifically. Next, we outline the Manoa School alternative futures method, and how we used it to design and carry out a “complete futures of x” project. Following the Manoa School approach, we describe four alternative futures for forestry and forest management. We conclude with implications for the future of forestry, forests, and forest-based nanomaterials, as well as a discussion on the implementation of a complete “futures of x” project.

scholarly journals PERFIL DOS INCÊNDIOS FLORESTAIS NO BRASIL DE 1994 A 1997

FLORESTA ◽  
2002 ◽  
Vol 32 (2) ◽  
Author(s):  
Ronaldo Viana Soares ◽  
Juliana Ferreira Santos
Keyword(s):  
Forest Fire ◽  
Vegetation Type ◽  
Secondary Growth ◽  
Minas Gerais ◽  
Size Class ◽  
Fire Season ◽  
Burned Area ◽  
Native Forest ◽  
Fire Statistics ◽  
Fire Control

O conhecimento do perfil dos incêndios florestais é muito importante para o planejamento do controle dos mesmos. O objetivo deste trabalho foi estabelecer o perfil dos incêndios florestais no país através de dados coletados, em áreas protegidas, no período de 1994 a 1997, através de formulários preenchidos por empresas e instituições florestais. Foram registrados e informados 1.957 incêndios e apesar deste número não representar a totalidade dos incêndios ocorridos no período estudado, constituiu-se numa base confiável para se conhecer as principais características dos incêndios. Os resultados mostraram que a área média atingida por incêndio no período analisado foi de aproximadamente 135 ha, sendo Minas Gerais o estado líder, tanto em número de incêndios informados (62,7% do total) como em área queimada (25,2%). O grupo Incendiários foi a principal causa dos incêndios, com 56,6% das ocorrências, vindo a seguir as Queimas para limpeza com 22,1%. Com relação à área queimada o grupo Queimas para limpeza , com 74,1% da superfície atingida, foi a principal causa, ficando o grupo Incendiários em segundo lugar com 19,8%. A principal estação de incêndios no país se estende de julho a novembro, quando ocorreram 79,2% dos incêndios, correspondendo a 98,6% da área atingida. O maior número de incêndios (39,7% das ocorrências) foi registrado em Outro tipo de vegetação, que inclui cerrado, capoeira e campo. Com relação à área atingida, entretanto, 92,5% foi registrada em Florestas Nativas. Quanto à distribuição dos incêndios através das classes de tamanho, 23,9% foi enquadrado na classe I ( 0,1 ha). É importante ressaltar que quanto maior a eficiência no combate aos incêndios, maior é a concentração dos mesmos na classe I. Apesar de corresponder a apenas 2,4% das ocorrências, os incêndios da classe V ( 200,0 ha) foram responsáveis por 94,5% da área queimada. FOREST FIRE STATISTICS IN BRAZIL FROM 1994 TO 1997 Abstract Forest fire statistics knowledge is an important tool for fire control planning. The objective of this research was to collect information on forest fire occurrence in Brazilian protected areas in the period of 1994 to 1997. The analyzed variables were the number of fires and burned areas per state of the federation, monthly distribution, probable causes, affected vegetation, size class distribution, and average burned area per fire. Results showed that the average burned area per fire was approximately 135 ha and Minas Gerais ranked first, both in number of registered fires (62.7%) and burned surface (25.2%). Incendiary, with 56.6% of the occurrences was the leading cause, followed by debris burning with 22.1%. However, as for the affected area, Debris burning was the leading cause (74.1%), followed by Incendiary (19.8%). The fire season extends from July to November, when 79.2% of the fires occurred, corresponding to 98.6% of the burned surface. Miscellaneous, that includes savanna, secondary growth forest, and grassland were the most affected vegetation type (39.7% of the occurrences). In relation to the burned surface, Native Forest (92.5%) ranked first. The distribution of the registered fires through the size classes presented 23.9% of the occurrences in Class I ( 0.1 ha), whereas 94.5% of the burned area were result of Class V ( 200 ha) fires. Size Class II (0.1 to 4.0 ha), with 49.1% of the occurrences, ranked first in number of registered fires during the analyzed period.

Messmate stringybark: bark ignitability and burning sustainability in relation to fragment dimensions, hazard score and time since fire

2017 ◽  
Vol 26 (10) ◽  
pp. 866 ◽  
Author(s):  
Tara E. Penman ◽  
Jane G. Cawson ◽  
Simon Murphy ◽  
Thomas J. Duff
Keyword(s):  
Physical Properties ◽  
Hazard Assessment ◽  
Fire Suppression ◽  
Assessment Methods ◽  
Tree Size ◽  
Fire Behaviour ◽  
Site Assessment ◽  
Field Surveys ◽  
Time Since Fire ◽  
Eastern Australia

Messmate stringybark is common in forests across south-eastern Australia. The bark of these trees is persistent and produces firebrands that contribute to house loss and the difficulty of fire suppression during wildfires. The trees typically survive fire with the amount of bark depleted. We compared two common methods to assess messmate bark fuels: (1) field-based hazard assessment, and (2) desk-based assessment using mapped time since fire. Our measurements included space-for-time field surveys and laboratory flammability tests. Although several physical properties of bark could be approximated from both assessment methods, some bark properties important to flammability were not captured. Ignitability was found to be dependent on the amount of char on bark fragments and could be predicted by the site assessment methods, whereas sustainability was dependent on bark fragment dimensions and could not be predicted by current methods. Bark fragment properties were found to be partially a function of tree size. Overall, these findings indicate that current bark assessment methods do not capture all the key bark properties that contribute to messmate bark’s flammability. Further research is warranted to improve bark assessment methods so they better reflect bark’s contribution to fire behaviour.

scholarly journals Challenging the Environmental History of the Cerrado: Science, Biodiversity and Politics on the Brazilian Agricultural Frontier

2020 ◽  
Vol 10 (1) ◽  
pp. 82-116 ◽  
Author(s):  
Sandro Dutra e Silva
Keyword(s):  
Environmental History ◽  
Political Process ◽  
Historical Change ◽  
Complex Relationship ◽  
Brazilian Cerrado ◽  
Agricultural Frontier ◽  
Environmental Consequences ◽  
Environmental Interactions ◽  
History Of

This article presents an overview of the environmental history of the Brazilian Cerrado, its environmental characteristics and the processes related to the historical change in the landscapes of this endangered ecosystem. It highlights competing classifications of the Cerrado, the role of politics in establishing them, and the environmental consequences of such classifications. More than just describing an environment, classifying an ecosystem is a political process that involves complex socio-environmental interactions. The sources used points out the different attempts to get to know and "conquered" the Cerrado, bringing together interdisciplinary perspectives from a variety of actors and institutions. Historiographic challenges go beyond environmental descriptions in that the socio-environmental interactions that made up this unique ecosystem are equally complex. This paper’s conclusions reinforce the interdisciplinary role of environmental history in the study of ecosystems and the complex relationship between culture and nature.

scholarly journals Podcast: Toxic City Under the Ice

Eos ◽  
2019 ◽  
Vol 100 ◽  
Author(s):  
Lauren Lipuma
Keyword(s):  
The Sun ◽  
Environmental Consequences ◽  
History Of

In the latest episode of its Centennial series, AGU’s Third Pod from the Sun recounts the history of a top-secret military project with unintended environmental consequences.

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