scholarly journals Landscape composition influences local pattern of fire size in the eastern Canadian boreal forest: role of weather and landscape mosaic on fire size distribution in mixedwood boreal forest using the Prescribed Fire Analysis System

2010 ◽  
Vol 19 (8) ◽  
pp. 1099 ◽  
Author(s):  
Christelle Hély ◽  
C. Marie-Josée Fortin ◽  
Kerry R. Anderson ◽  
Yves Bergeron
Keyword(s):  
Boreal Forest ◽  
Prescribed Fire ◽  
Boreal Forests ◽  
Weather Conditions ◽  
Landscape Composition ◽  
Burned Area ◽  
Fire Size ◽  
Fire Cycle ◽  
Area Burned ◽  
Analysis System

Wildfire simulations were carried out using the Prescribed Fire Analysis System (PFAS) to study the effect of landscape composition on fire sizes in eastern Canadian boreal forests. We used the Lake Duparquet forest as reference, plus 13 forest mosaic scenarios whose compositions reflected lengths of fire cycle. Three fire weather risks based on duff moisture were used. We performed 100 simulations per risk and mosaic, with topography and hydrology set constant for the reference. Results showed that both weather and landscape composition significantly influenced fire sizes. Weather related to fire propagation explained almost 79% of the variance, while landscape composition and weather conditions for ignition explained ∼14 and 2% respectively. In terms of landscape, burned area increased with increasing presence of shade-tolerant species, which are related to long fire cycles. Comparisons among the distributions of cumulated area burned from scenarios plus those from the Société de Protection des Forêts contre le Feu database archives showed that PFAS simulated realistic fire sizes using the 80–100% class of probable fire extent. Future analyses would best be performed on a larger region as the limited size of the study area could not capture fires larger than 11 000 ha, which represent 3% of fires but 65% of the total area burned at the provincial scale.

Fire emissions estimates in Siberia: evaluation of uncertainties in area burned, land cover, and fuel consumption

2013 ◽  
Vol 43 (5) ◽  
pp. 493-506 ◽  
Author(s):  
Elena A. Kukavskaya ◽  
Amber J. Soja ◽  
Alexander P. Petkov ◽  
Evgeni I. Ponomarev ◽  
Galina A. Ivanova ◽  
...  
Keyword(s):  
Land Cover ◽  
Fuel Consumption ◽  
Boreal Forests ◽  
Carbon Budget ◽  
Natural Disturbance ◽  
Weather Conditions ◽  
Burned Area ◽  
Data Sets ◽  
Fire Emissions ◽  
Area Burned

Boreal forests constitute the world's largest terrestrial carbon pools. The main natural disturbance in these forests is wildfire, which modifies the carbon budget and atmosphere, directly and indirectly. Wildfire emissions in Russia contribute substantially to the global carbon cycle and have potentially important feedbacks to changing climate. Published estimates of carbon emissions from fires in Russian boreal forests vary greatly depending on the methods and data sets used. We examined various fire and vegetation products used to estimate wildfire emissions for Siberia. Large (up to fivefold) differences in annual and monthly area burned estimates for Siberia were found among four satellite-based fire data sets. Official Russian data were typically less than 10% of satellite estimates. Differences in the estimated proportion of annual burned area within each ecosystem were as much as 40% among five land-cover products. As a result, fuel consumption estimates would be expected to vary widely (3%–98%) depending on the specific vegetation mapping product used and as a function of weather conditions. Verification and validation of burned area and land-cover data sets along with the development of fuel maps and combustion models are essential for accurate Siberian wildfire emission estimates, which are central to balancing the carbon budget and assessing feedbacks to climate change.

Relations between tree-ring widths, climate, and annual area burned in the boreal forest of Alberta

1995 ◽  
Vol 25 (11) ◽  
pp. 1746-1755 ◽  
Author(s):  
C.P.S. Larsen ◽  
G.M. MacDonald
Keyword(s):  
Boreal Forest ◽  
Tree Ring ◽  
National Park ◽  
Ring Width ◽  
Weather Conditions ◽  
Fire Weather ◽  
Severity Rating ◽  
Area Burned ◽  
Positive Correlations ◽  
Wood Buffalo National Park

Ring-width chronologies from three white spruce (Piceaglauca (Moench) Voss) and two jack pine (Pinusbanksiana Lamb.) sites in the boreal forest of northern Alberta were constructed to determine whether they could provide proxy records of monthly weather, summer fire weather, and the annual area burned by wildfires in Wood Buffalo National Park. All but one of the standard and residual chronologies exhibited significant positive correlations with June precipitation in the growth year, and all but three of the chronologies exhibited positive correlations with precipitation in June, July, or August of the previous year. Three of the residual chronologies also exhibited negative correlations with June temperature in the growth year. Four of the standard and residual chronologies exhibited significant correlations with the Seasonal Severity Rating fire weather variable from Fort Smith, N.W.T. Four of the standard chronologies and three of the residual chronologies exhibited significant correlations with the annual area burned in Wood Buffalo National Park. Significant correlations were also found for some of the standard and residual chronologies with fire weather and annual area burned in the previous year. These results suggest that ring widths and annual area burned in this portion of the boreal forest are sensitive to similar weather conditions. Tree-ring records may therefore provide a useful means of examining decadal to centennial length relations between climate and annual area burned in the boreal forest.

Fires can overwinter in boreal forests of North America

2020 ◽  
Author(s):  
Rebecca Scholten ◽  
Sander Veraverbeke
Keyword(s):  
North America ◽  
Boreal Forest ◽  
Northwest Territories ◽  
Boreal Forests ◽  
Fire Spread ◽  
Burned Area ◽  
Organic Soils ◽  
Boreal Winter ◽  
Large Fire ◽  
Lightning Strikes

<div>The boreal forest stores 35 % of the world’s soil carbon reserves. Wildfires burn frequently in the boreal forest of North America and drive the boreal forest carbon balance. Previously, lightning strikes and human activities were identified as the sole ignition sources for wildfires in the boreal regions of North America. In recent years however, fire managers in Alaska, USA and Northwest Territories, Canada have started reporting the occurrence of overwintering fires. Overwintering fires are fires, that survive the cold and wet boreal winter by smouldering in deep, carbon-rich soils and re-emerge early in the subsequent spring, when fire weather favours fire spread.</div><div>Using the location and ignition dates of 42 overwintering fires reported by fire managers in Alaska and Northwest Territories between 2002 and 2017, we developed an algorithm to identify these new ignition sources. Our algorithm detected 8 out of 9 additional reported fires we used for validation, and further identified 15 unreported overwintering fires. Even though overwintering fires make up only 0.5 % of the burned area in total, they can amount to up to more than 10 % of the annual burned area after exceptionally large fire years.</div><div>We found that overwintering of fires is facilitated by deep burning into the organic soils. Overwintering fires occur more frequently after large fire years in combination with subsequent mild winters and springs leading to an early snowmelt.</div><div>In a warming climate, the boreal forest is burning more frequently and more intensely. As a consequence, the burned area and burn depth are predicted to increase. Our results suggest that overwintering fires are closely tied to these conditions and will therefore occur more often in the future.</div>

Landscape structural features control fire size in a Mediterranean forested area of central Spain

2009 ◽  
Vol 18 (5) ◽  
pp. 575 ◽  
Author(s):  
Olga Viedma ◽  
D. G. Angeler ◽  
José M. Moreno
Keyword(s):  
Land Cover ◽  
Landscape Structure ◽  
Weather Conditions ◽  
Structural Features ◽  
Burned Area ◽  
Linear Regression Models ◽  
Fire Size ◽  
Central Spain ◽  
Fire Propagation ◽  
Landscape Characteristics

Landscape structure may affect fire propagation and fire size. Propagation may be favoured in landscapes that are homogeneous and hindered at places of greater heterogeneity, and where discontinuities occur. We tested whether there is continuity in landscape structure across the edges of 110 fires in the Sierra de Gredos (central Spain). We used Landsat Multispectral Scanner images to map and assess the land-cover composition and other features of fires. Landscape diversity along the pixel row of the fire edge and of the two adjacent ones (burned and unburned) was compared for all fires. Additionally, changes in landscape properties and fuel hazard perpendicular to the fire edge evaluated the degree of discontinuity from inside the burn towards the outside across the edge. Fire size was related to landscape properties and weather conditions using generalized linear regression models. Diversity increased from inside the burn towards the edge and outside the burn. Discontinuity in land-cover types and fuel hazard increased from the inside towards the outside. Modelling confirmed that fire size was in part related to landscape characteristics of the burned area and of the edges of the fire perimeter. We conclude that landscape structure was important in determining fire size in this area.

scholarly journals A Comparative Analysis of Burned Area Datasets in Canadian Boreal Forest in 2000

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Laia Núñez-Casillas ◽  
José Rafael García Lázaro ◽  
José Andrés Moreno-Ruiz ◽  
Manuel Arbelo
Keyword(s):  
Comparative Analysis ◽  
Boreal Forest ◽  
Boreal Forests ◽  
Burned Area ◽  
Diverse Group ◽  
Spatial Accuracy ◽  
Noaa Avhrr ◽  
Fire Activity ◽  
Canadian Boreal Forest ◽  
Area Data

The turn of the new millennium was accompanied by a particularly diverse group of burned area datasets from different sensors in the Canadian boreal forests, brought together in a year of low global fire activity. This paper provides an assessment of spatial and temporal accuracy, by means of a fire-by-fire comparison of the following: two burned area datasets obtained from SPOT-VEGETATION (VGT) imagery, a MODIS Collection 5 burned area dataset, and three different datasets obtained from NOAA-AVHRR. Results showed that burned area data from MODIS provided accurate dates of burn but great omission error, partially caused by calibration problems. One of the VGT-derived datasets (L3JRC) represented the largest number of fire sites in spite of its great overall underestimation, whereas the GBA2000 dataset achieved the best burned area quantification, both showing delayed and very variable fire timing. Spatial accuracy was comparable between the 5 km and the 1 km AVHRR-derived datasets but was remarkably lower in the 8 km dataset leading, us to conclude that at higher spatial resolutions, temporal accuracy was lower. The probable methodological and contextual causes of these differences were analyzed in detail.

scholarly journals Drought Modulated Boreal Forest Fire Occurrence and Linkage with La Nina Events in Altai Mountains, Northwest China

2020 ◽  
Author(s):  
Chunming Shi ◽  
Ying Liang ◽  
Cong Gao ◽  
Fengjun Zhao ◽  
Qiuhua Wang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Boreal Forest ◽  
Forest Fire ◽  
El Niño ◽  
Boreal Forests ◽  
El Nino ◽  
Fire Frequency ◽  
Burned Area ◽  
Fire Occurrence ◽  
La Nina

Warming-induced drought stress and El Nino associated summer precipitation failure are responsible for increased forest fire intensities of tropical and temperate forests in Asia and Australia. However, both effects are unclear for boreal forests, the largest biome and carbon stock over land. Here we combined fire frequency, burned area and climate data in the Altai boreal forests, the southmost extension of Siberia boreal forest into China, and explored their link with ENSO (El Nino and South Oscillation). Surprisingly, both summer drought severity and fire occurrence have shown significant (P<0.05) teleconnections with La Nina events of the previous year, and therefore provide an important reference for forest fire prediction and prevention in Altai. Despite a significant warming trend, the increased moisture over Altai has largely offset the effect of warming-induced drought stress, and lead to an insignificant fire frequency trend in the last decades, and largely reduced burned area since the 1980s. The reduced burned area could also benefit from the fire suppression efforts and greatly increased investment in fire prevention since 1987.

Fire impacts and crowning in the boreal forest: study of a large wildfire in western Quebec

2001 ◽  
Vol 10 (2) ◽  
pp. 119 ◽  
Author(s):  
Victor Kafka ◽  
Sylvie Gauthier ◽  
Yves Bergeron
Keyword(s):  
Boreal Forest ◽  
Forest Canopy ◽  
Linear Models ◽  
Weather Conditions ◽  
Ecological Impacts ◽  
Stand Age ◽  
Burned Area ◽  
Stepwise Logistic Regression ◽  
Site Factors ◽  
The North

Within the context of studying the ecological impacts of wildland fires in the boreal forest, a spatial analysis of a major wildfire was conducted. The fire covered nearly 500 km 2 in the north-western part of Quebec’s boreal forest in the summer of 1995. The spatial distribution of different fire impacts on the forest canopy was obtained using timber damage assessment maps. Fire impacts varied throughout the burned area, ranging from areas where trees had completely burned crowns (43%) to remaining patches of trees with green foliage (3%). The effects of local stand and site factors on crown fire, as assessed by the fire impacts, were evaluated using geographic information systems. Despite the large extent and high intensity of the wildfire created by extreme fire weather conditions, stepwise logistic regression and analysis by log–linear models indicated that variations in surface material, stand composition, and estimated stand age played a role in the presence or absence of crowning at the stand level. However, it appears that height and density of stand, as well as topography, did not have a significant influence. Our study presents the variability of fire impacts and its implications, and it provides a better understanding of the relationships between landscape components and fire crowning. Résumé.Dans le cadre de l’étude de la dynamique de la for&ecircumflex;t boréale, une analyse d’un grand incendie a été réalisée. À la fin de l’été 1995, cet incendie a couvert un territoire de près de 500 km 2 dans la partie nord-ouest de la for&ecircumflex;t boréale québécoise. La distribution spatiale des impacts du feu sur la voute forestière a été obtenue à partir de cartes d’évaluation des dommages aux for&ecircumflex;ts causés par le feu. Dans la zone br&ucircumflex;lée, la gamme des impacts de l’incendie varie d’étendues où les arbres présentent des cimes complètement br&ucircumflex;lées (43%) à des secteurs où le feuillage des arbres est demeuré vert (3%). L’effet de facteurs biotiques et abiotiques sur l’occurrence d’un feu de cime a été établi à l’aide d’un système d’information géographique. Une régression logistique pas à pas et une analyse de modèles log-linéaires ont révélé que certaines modalités des dépôts de surface, de la composition et de l’âge du peuplement ont joué un rôle important dans l’occurrence d’un feu de cime au niveau du peuplement. Par contre, il semble que la hauteur et la densité du peuplement, ainsi que la topographie, n’aient pas eu d’effets significatifs. Notre étude met en lumière la variabilité et l’importance des impacts d’un incendie, tout en permettant de mieux comprendre la relation entre les composantes du territoire et le comportement des incendies.

Mapping the Location of Wildfires in Alaskan Boreal Forests Using AVHRR Imagery

1995 ◽  
Vol 5 (2) ◽  
pp. 55 ◽  
Author(s):  
NHF French ◽  
ES Kasischke ◽  
LL Bourgeau-Chavez ◽  
D Berry
Keyword(s):  
Boreal Forest ◽  
Satellite Imagery ◽  
Forest Fire ◽  
Forest Fires ◽  
Boreal Forests ◽  
Fire Scars ◽  
Area Burned ◽  
Avhrr Data ◽  
Avhrr Imagery

The results of a study using satellite imagery to map boreal forest fires in Alaska in 1990 and 1991 are presented. Composite AVHRR data detected more than 80% of fires greater than 2000 ha in size. Additionally, using a two season method, 78% of the area of all boreal forest fires in Alaska was mapped. This technique is considered to be an accurate way to detect forest fire scars and estimate area burned throughout the boreal forests, and could be very important in those regions where wildfire data are presently difficult or impossible to gather.

Microbial Processes in the Alaskan Boreal Forest

2006 ◽  
Author(s):  
Joshua P. Schimel ◽  
F. Stuart Chapin III
Keyword(s):  
Boreal Forest ◽  
Tree Growth ◽  
Boreal Forests ◽  
Growing Season ◽  
Microbial Processes ◽  
Soil Processes ◽  
Forest Stands ◽  
Soil System ◽  
Fire Cycle ◽  
Successional Stages

Forest ecosystems typically occur in moderate environments where growing season rainfall is adequate to support tree growth and where nongrowing season conditions are not too extreme. The Alaskan boreal forests, however, occur at the limit of the forest biome, in an environment that is climatically extreme, with strong physical gradients. The seasonal variation in temperature is among the greatest on earth, with winter temperatures as low as –50ºC and summer growing season temperatures that can reach +30ºC (Chapter 4). The growing season is short, the climate is semi-arid, and growing season rainfall is limited. Forests exist in the region because evapotranspiration is also limited. Steep south-facing slopes can be too dry to support tree growth (Chapter 6). In contrast, in flat, low-lying areas, low evapotranspiration combined with permafrost produces wetlands despite the low rainfall. Regular drought makes the forest highly susceptible to fires. At large scales (many square kilometers), the boreal forest experiences regular, extensive fires that destroy whole stands, resetting succession (Chapter 17). This regular fire cycle produces a patchwork mosaic of forest stands in different successional stages across the landscape (Dyrness et al. 1986, Kasischke and Stocks 2000; Chapter 7). In large rivers (e.g., the Tanana), the cutting and filling of meander loops washes away some forest stands while depositing new silt bars for colonization and succession (Zasada 1986). At the landscape scale, the biogeochemical cycles in the boreal forest are therefore dominated by landscape structure (e.g., dry uplands vs. wet lowlands) and by disturbance (particularly fire). At smaller scales, however, the strong feedbacks between plant and soil processes control much of the functioning of individual forest stands, and possibly the rate of transition among successional stages. In this chapter, we discuss how microbial processes in the boreal forest produce unusual patterns of nutrient cycling that drive the overall functioning of boreal forest stands. Figure 14.1 illustrates the linkages between plant and microbial communities that dominate the functioning of the boreal forest soil system. In the feedbacks between plant and soil processes, plants drive the loop largely through inputs of organic materials.

Comment—A re-examination of the effects of fire suppression in the boreal forest

2001 ◽  
Vol 31 (8) ◽  
pp. 1462-1466 ◽  
Author(s):  
K Miyanishi ◽  
E A Johnson
Keyword(s):  
Boreal Forest ◽  
Fire Management ◽  
Fire Suppression ◽  
Fire Frequency ◽  
Stand Age ◽  
Reliable Estimate ◽  
Fire Size ◽  
Fire Cycle ◽  
Large Fires ◽  
In Fire

A report by Ward and Tithecott (P.C. Ward and A.G. Tithecott. 1993. Ontario Ministry of Natural Resources, Aviation, Flood and Fire Management Branch, Publ. 305.) is frequently cited in the literature as providing evidence of the effects of fire suppression on the boreal forest. The study is based on 15 years of fire data and stand age data from Ontario, Canada. A re-examination of this report reveals serious flaws that invalidate the conclusions regarding effects of fire suppression on fire size and fire frequency. The fire-size data from the unprotected zone are censored in the small size classes because of detection resolution, invalidating comparisons of shapes of the distributions between the protected and unprotected zones. Use of different plotting scales gives the false appearance of large differences in the number of large fires between the two zones. Stand age data are used to show a change in fire frequency in the 20th century, and this change is attributed to fire suppression. However, no evidence is presented to conclude that this change in fire frequency is attributable to fire suppression and not to climate change. The estimate of the current fire cycle is based on too short a record to give a reliable estimate given the variation in annual area burned. Therefore, this report does not present sound evidence of fire suppression effects and should not be cited as such.

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