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.

scholarly journals Satellite Detection Limitations of Sub-Canopy Smouldering Wildfires in the North American Boreal Forest

Fire ◽  
2018 ◽  
Vol 1 (2) ◽  
pp. 28 ◽  
Author(s):  
Joshua Johnston ◽  
Lynn Johnston ◽  
Martin Wooster ◽  
Alison Brookes ◽  
Colin McFayden ◽  
...  
Keyword(s):  
Boreal Forest ◽  
North American ◽  
Land Surface ◽  
Forest Canopy ◽  
Infrared Imaging ◽  
Time Window ◽  
Detection Threshold ◽  
Fire Detection ◽  
Canopy Interception ◽  
The North

We develop a simulation model for prediction of forest canopy interception of upwelling fire radiated energy from sub-canopy smouldering vegetation fires. We apply this model spatially across the North American boreal forest in order to map minimum detectable sub-canopy smouldering fire size for three satellite fire detection systems (sensor and algorithm), broadly representative of the Moderate Resolution Imaging Spectroradiometer (MODIS), Sea and Land Surface Temperature Radiometer (SLSTR) and Visible Infrared Imaging Radiometer Suite (VIIRS). We evaluate our results according to fire management requirements for “early detection” of wildland fires. In comparison to the historic fire archive (Canadian National Fire Database, 1980–2017), satellite data with a 1000 m pixel size used with an algorithm having a minimum MWIR channel BT elevation threshold of 5 and 3 K above background (e.g., MODIS or SLSTR) proves incapable of providing a sub-0.2 ha smouldering fire detection 70% and 45% of the time respectively, even assuming that the sensor overpassed the relevant location within the correct time window. By contrast, reducing the pixel area by an order of magnitude (e.g., 375 m pixels of VIIRS) and using a 3.5 K active fire detection threshold offers the potential for successfully detecting all fires when they are still below 0.2 ha. Our results represent a ‘theoretical best performance’ of remote sensing systems to detect sub-canopy smoldering fires early in their lifetime.

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.

scholarly journals Morphological variability in coenopopulations of the rare species Adonis villosa Ledeb. (Ranunculaceae) in the North Altai

2021 ◽  
Vol 10 (1) ◽  
pp. 24-32
Author(s):  
Altynai Alekseevna Achimova ◽  
Olga Nikolaevna Papina ◽  
Elena Viktorovna Zhmud
Keyword(s):  
Rare Species ◽  
Forest Canopy ◽  
Morphological Variability ◽  
Weather Conditions ◽  
Limiting Factors ◽  
The North ◽  
Lateral Shoots ◽  
The Right ◽  
Favorable Conditions ◽  
Observation Period

This paper examines the morphological variability in coenopopulations of the rare species Adonis villosa Ledeb., which grows in the North Altai. We have described the features of the places where this rare species grows in the Maiminsky (on the right bank of the Maima river, in the vicinity of the villages of Maima, Kyzyl-Ozek, Kutash) and Choysky Districts (in the vicinity of the villages of Choya, Karasuk, Paspaul, Levinka). The studies of intra- and inter-population variability in dynamics over the years were conducted. It is established that the degree of variability of morphological features in similar ecological and geographical conditions is influenced by weather conditions. Based on the analysis of the state of the studied coenopopulations, the limiting factors for the growth and development of plants and the most favorable conditions for the introduction of this rare species into the culture were identified. The limiting factors should be considered insufficient moisture in the winter-spring period, a higher altitude location, the presence of low grassy cover and the absence of woody and shrubby vegetation. All the A. villosa specimens we studied were confined to well-warmed, open slopes, mainly in the southern exposure. In the most favorable conditions, up to 7 lateral shoots can form on the axial shoot. In most cases, individuals of A. villosa form 23 lateral shoots. It was found that the parameters of the length of generative shoots were characterized by higher variability than the number of enrichment shoots. During the three-year observation period, individuals growing on the edge of the forest canopy were significantly higher. The shortest individuals were recorded (the height did not exceed 20 cm) in the coenopopulation located on an open, uncultivated area with low grass cover.

scholarly journals Understanding the Impact of Different Landscape-Level Fuel Management Strategies on Wildfire Hazard in Central Portugal

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 522
Author(s):  
Akli Benali ◽  
Ana C. L. Sá ◽  
João Pinho ◽  
Paulo M. Fernandes ◽  
José M. C. Pereira
Keyword(s):  
Management Strategies ◽  
Treatment Strategies ◽  
Fire Season ◽  
Burned Area ◽  
Treatment Area ◽  
Fuel Treatment ◽  
The North ◽  
Wildfire Hazard ◽  
Central Portugal ◽  
The Impact

The extreme 2017 fire season in Portugal led to widespread recognition of the need for a paradigm shift in forest and wildfire management. We focused our study on Alvares, a parish in central Portugal located in a fire-prone area, which had 60% of its area burned in 2017. We evaluated how different fuel treatment strategies may reduce wildfire hazard in Alvares through (i) a fuel break network with different extents corresponding to different levels of priority and (ii) random fuel treatments resulting from a potential increase in stand-level management intensity. To assess this, we developed a stochastic wildfire simulation system (FUNC-SIM) that integrates uncertainties in fuel distribution over the landscape. If the landscape remains unchanged, Alvares will have large burn probabilities in the north, northeast and center-east areas of the parish that are very often associated with high fireline intensities. The different fuel treatment scenarios decreased burned area between 12.1–31.2%, resulting from 1–4.6% increases in the annual treatment area and reduced the likelihood of wildfires larger than 5000 ha by 10–40%. On average, simulated burned area decreased 0.22% per each ha treated, and cost-effectiveness decreased with increasing area treated. Overall, both fuel treatment strategies effectively reduced wildfire hazard and should be part of a larger, holistic and integrated plan to reduce the vulnerability of the Alvares parish to wildfires.

scholarly journals Synthesizing published knowledge of boreal forest cover change for large-scale landscape dynamics modelling

2003 ◽  
Vol 79 (1) ◽  
pp. 132-146 ◽  
Author(s):  
Dennis Yemshanov ◽  
Ajith H Perera
Keyword(s):  
Boreal Forest ◽  
Large Scale ◽  
Forest Canopy ◽  
Forest Cover ◽  
Forest Succession ◽  
Simulation Models ◽  
Limiting Factors ◽  
Sources Of Information ◽  
Forest Cover Change ◽  
Discrete State

We reviewed the published knowledge on forest succession in the North American boreal biome for its applicability in modelling forest cover change over large extents. At broader scales, forest succession can be viewed as forest cover change over time. Quantitative case studies of forest succession in peer-reviewed literature are reliable sources of information about changes in forest canopy composition. We reviewed the following aspects of forest succession in literature: disturbances; pathways of post-disturbance forest cover change; timing of successional steps; probabilities of post-disturbance forest cover change, and effects of geographic location and ecological site conditions on forest cover change. The results from studies in the literature, which were mostly based on sample plot observations, appeared to be sufficient to describe boreal forest cover change as a generalized discrete-state transition process, with the discrete states denoted by tree species dominance. In this paper, we outline an approach for incorporating published knowledge on forest succession into stochastic simulation models of boreal forest cover change in a standardized manner. We found that the lack of details in the literature on long-term forest succession, particularly on the influence of pre-disturbance forest cover composition, may be limiting factors in parameterizing simulation models. We suggest that the simulation models based on published information can provide a good foundation as null models, which can be further calibrated as detailed quantitative information on forest cover change becomes available. Key words: probabilistic model, transition matrix, boreal biome, landscape ecology

scholarly journals Controlling Shipping Along the North European Trade Axis

1971 ◽  
Vol 24 (4) ◽  
pp. 553-556
Author(s):  
D. J. Lindsay
Keyword(s):  
Weather Conditions ◽  
North Coast ◽  
Baltic Basin ◽  
Long Distance ◽  
The North ◽  
Large Numbers ◽  
Straight Line ◽  
European Trade ◽  
Trade Route ◽  
The Baltic

By the North European Trade Axis is meant the trade route from Ushant and Land's End, up the English Channel, through the Dover Strait fanning out to serve eastern England, the north coast of continental Europe and leading to the Baltic Basin. Recent events in this area have left a feeling that some form of tightening of control is not only desirable, but is rapidly becoming imperative. There is a basic conflict between the two forms of shipping using the area: the local users who use the area more or less constantly, and the long-distance traders, usually much larger, which arrive in the area for a brief stay after a prolonged period at sea, which has usually been in good weather conditions. Frequently these latter ships have a very poor notion of the hornet's nest into which they are steaming when they arrive. The net result is all too often the same: the local users, with familiarity breeding contempt, wander about as they see fit, with scant regard for routing or the regulations; all too often the big ships arrive from sea with navigating staffs who are too confused, sometimes too ignorant—and sometimes too terrified—to do much more than blunder forward in a straight line hoping for the best. Quite obviously this is not a total picture, and there are large numbers of ships which navigate perfectly competently, but the minority of those which do not seem to be rising rapidly, and show every sign of continuing to increase.

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