Spatial pattern analyses of post-fire residual stands in the black spruce boreal forest of western Quebec

2010 ◽  
Vol 19 (8) ◽  
pp. 1110 ◽  
Author(s):  
Amar Madoui ◽  
Alain Leduc ◽  
Sylvie Gauthier ◽  
Yves Bergeron
Keyword(s):  
Black Spruce ◽  
Weather Conditions ◽  
Spatial Analyses ◽  
Fire Size ◽  
The West ◽  
Forest Patches ◽  
Burned Areas ◽  
Large Fires ◽  
The Many ◽  
Landsat Satellite

In this study, we characterised the composition and configuration of post-fire residual habitats belonging to two physiographic zones of the black spruce–moss domain in western Quebec. Thirty-three large fires (2000–52 000 ha) were selected and extracted on classified Landsat satellite imagery. The results show that a minimum of 2% and a maximum of 22% of burned areas escaped fire, with an overall average of 10.4%. The many forest patches that partially or entirely escaped fire formed residual habitats (RHs). It was found that although the area of RHs follows a linear relationship with fire size, their proportion appears relatively constant. Spatial analyses showed that the fires could be separated into two groups depending on the physiographic zones (East-Canadian Shield v. West-Clay Belt Lowlands). Fires in the west zone generate less RHs and appear to be associated with more extreme weather conditions. In most cases there was no association with water or wetlands; in some fires the presence of RHs is associated with the proximity of water bodies. The failure to find an association between RHs and wetlands suggests that this type of environment is part of the fuel. Coniferous woodland with moss appears particularly overrepresented within RHs. Our results suggest that the local and regional physiographic conditions strongly influence the creation of RHs; therefore, it is important to consider those differences when applying ecosystem-based management.

scholarly journals Contrasting large fire activity in the French Mediterranean

2019 ◽  
Vol 19 (5) ◽  
pp. 1055-1066 ◽  
Author(s):  
Anne Ganteaume ◽  
Renaud Barbero
Keyword(s):  
Fire Suppression ◽  
Sharp Decrease ◽  
Weather Conditions ◽  
Fire Spread ◽  
Return Level ◽  
Fire Season ◽  
Burned Area ◽  
The West ◽  
Forest Resilience ◽  
Large Fires

Abstract. In the French Mediterranean, large fires have significant socioeconomic and environmental impacts. We used a long-term georeferenced fire time series (1958–2017) to analyze both spatial and temporal distributions of large fires (LFs; ≥100 ha). The region was impacted in some locations up to six times by recurrent LFs and 21 % of the total area burned by LFs occurred on a surface that previously burned in the past, with potential impact on forest resilience. We found contrasting patterns between the east and the west of the study area, the former experiencing fewer LFs but of a larger extent compared to the latter, with an average time of occurrence between LFs exceeding 4000 ha < 7 years mostly in the eastern coastal area and > 50 years in the west. This longitudinal gradient in LF return level contrasts with what we would expect from mean fire weather conditions strongly decreasing eastwards during the fire season but is consistent with larger fuel cover in the east, highlighting the strong role of fuel continuity in fire spread. Additionally, our analysis confirms the sharp decrease in both LF frequency and burned area in the early 1990s, due to the efficiency of fire suppression and prevention reinforced at that time, thereby weakening the functional climate–fire relationship across the region.

scholarly journals The Role of Previous Fires in the Management and Expenditures of Subsequent Large Wildfires

Fire ◽  
2019 ◽  
Vol 2 (4) ◽  
pp. 57 ◽  
Author(s):  
Erin J Belval ◽  
Christopher D O’Connor ◽  
Matthew P Thompson ◽  
Michael S Hand
Keyword(s):  
United States ◽  
Regression Models ◽  
Fire Management ◽  
Fire Behavior ◽  
Western United States ◽  
Fire Size ◽  
Burned Areas ◽  
Large Fires ◽  
Percent Area

Previously burned areas can influence the occurrence, extent, and severity of subsequent wildfires, which may influence expenditures on large fires. We develop a conceptual model of how interactions of fires with previously burned areas may influence fire management, fire behavior, expenditures, and test hypotheses using regression models of wildfire size and suppression expenditures. Using a sample of 722 large fires from the western United States, we observe whether a fire interacted with a previous fire, the percent area of fires burned by previous fires, and the percent perimeter overlap with previous fires. Fires that interact with previous fires are likely to be larger and have lower total expenditures on average. Conditional on a fire encountering a previous fire, a greater extent of interaction with previous fires is associated with reduced fire size but higher expenditures, although the expenditure effect is small and imprecisely estimated. Subsequent analysis suggests that fires that interact with previous fires may be systematically different from other fires along several dimensions. We do not find evidence that interactions with previous fires reduce suppression expenditures for subsequent fires. Results suggest that previous fires may allow suppression opportunities that otherwise might not exist, possibly reducing fire size but increasing total expenditures.

Spatial and temporal extremes of wildfire sizes in Portugal (1984–2004)

2009 ◽  
Vol 18 (8) ◽  
pp. 983 ◽  
Author(s):  
P. de Zea Bermudez ◽  
J. Mendes ◽  
J. M. C. Pereira ◽  
K. F. Turkman ◽  
M. J. P. Vasconcelos
Keyword(s):  
Generalized Pareto Distribution ◽  
Fire Regimes ◽  
Temporal Analysis ◽  
Extreme Value Statistics ◽  
Spatial And Temporal Patterns ◽  
Burned Areas ◽  
Environmental Correlates ◽  
Original Dataset ◽  
Large Fires ◽  
Landsat Satellite

Spatial and temporal patterns of large fire (>100 ha) incidence in Portugal over the period 1984–2004 were modeled using extreme value statistics, namely the Peaks Over Threshold approach, which uses the Generalized Pareto Distribution (GPD) as a model. The original dataset includes all fires larger than 5 ha (30 616 fires) that were observed in Portugal during the study period, mapped from Landsat satellite imagery. The country was divided into eight regions, considered internally homogeneous from the perspective of their fire regimes and respective environmental correlates. The temporal analysis showed that there does not appear to be any trend in the incidence of very large fires, but revealed a cyclical behavior in the values of the GPD shape parameter, with a period in the range of 3 to 5 years. Spatial analysis highlighted strong regional differences in the incidence of large fires, and allowed the calculation of return levels for a range of fire sizes. This analysis was affected by the presence of a few outlying observations, which may correspond to clusters of contiguous fire scars, resulting in artificially large burned areas. We discuss some of the implications of our findings in terms of consequences for fire management aimed at preventing the occurrence of extremely large fires, and present ideas for extending the present study.

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.

Assessing the effect of a fuel break network to reduce burnt area and wildfire risk transmission

2016 ◽  
Vol 25 (6) ◽  
pp. 619 ◽  
Author(s):  
Tiago M. Oliveira ◽  
Ana M. G. Barros ◽  
Alan A. Ager ◽  
Paulo M. Fernandes
Keyword(s):  
Treatment Option ◽  
Weather Conditions ◽  
Risk Governance ◽  
Fire Size ◽  
Fuel Treatments ◽  
Management Scenarios ◽  
Management Options ◽  
Burnt Area ◽  
Burn Probability ◽  
Large Fires

Wildfires pose complex challenges to policymakers and fire agencies. Fuel break networks and area-wide fuel treatments are risk-management options to reduce losses from large fires. Two fuel management scenarios covering 3% of the fire-prone Algarve region of Portugal and differing in the intensity of treatment in 120-m wide fuel breaks were examined and compared with the no-treatment option. We used the minimum travel time algorithm to simulate the growth of 150 000 fires under the weather conditions historically associated with large fires. Fuel break passive effects on burn probability, area burned, fire size distribution and fire transmission among 20 municipalities were analysed. Treatments decreased large-fire incidence and reduced overall burnt area up to 17% and burn probability between 4% and 31%, depending on fire size class and treatment option. Risk transmission among municipalities varied with community. Although fire distribution shifted and large events were less frequent, mean treatment leverage was very low (1 : 26), revealing a very high cost–benefit ratio and the need for engaging forest owners to act in complementary area-wide fuel treatments. The study assessed the effectiveness of a mitigating solution in a complex socioecological system, contributing to a better-informed wildland fire risk governance process among stakeholders.

scholarly journals Impact of wildfire size on snowshoe hare relative abundance in southern British Columbia, Canada

Fire Ecology ◽  
2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Jenna Hutchen ◽  
Karen E. Hodges
Keyword(s):  
British Columbia ◽  
Relative Abundance ◽  
Pinus Contorta ◽  
Snowshoe Hare ◽  
Fire Size ◽  
Fire Scars ◽  
Burned Areas ◽  
Snowshoe Hares ◽  
Large Fires ◽  
Highly Correlated

Abstract Background Large wildfires result in more heterogeneous fire scars than do smaller fires because of differences in landscape context and high variability in burn intensity and severity. Previous research on mammal response to wildfire has often considered all fires as comparable disturbances regardless of size. Here, we explicitly examine whether fire size affects relative abundances of a keystone herbivore, snowshoe hare (Lepus americanus Erxleben, 1777), in regenerating stands of the same age. We surveyed vegetation and fecal pellets of snowshoe hares in nine 13-year-old wildfires, specifically, three fires in three size categories—small (80 to 200 ha), medium (1000 to 5000 ha), and large (>10 000 ha)—and in mature forests in southern British Columbia, Canada. Results Snowshoe hare density was low (0.4 hares ha−1), but hares were present at 57% of mature sites. Hares were absent from all areas where small fires had burned and were found in only one medium area post fire (0.2 hares ha−1). Hares were found within the fire scars of all three large burned areas, and with much higher numbers (3.8 hares ha−1) than in the medium fire area or mature forest. Snowshoe hare abundance was highly correlated with the number of sapling trees, especially lodgepole pine (Pinus contorta Douglas ex Loudon). Sapling densities were highly variable, but dense stands of saplings were found only in burn scars from large wildfires. Conclusions Fire size is an important predictor of snowshoe hare relative abundance in areas that are regenerating post fire; fires of different sizes are not comparable disturbances. Specifically, the post-fire heterogeneity after large fires enabled both the highest hare numbers as well as patches with no hares. These results suggest that forest and wildlife managers should protect areas with dense regeneration post fire, as these sites are necessary for hares after large wildfires.

Last Jewish Writings, 1915–1918

2018 ◽  
Author(s):  
Frederick C. Beiser
Keyword(s):  
Western World ◽  
The West ◽  
Rational Form ◽  
Jewish Communities ◽  
Special Obligation ◽  
Moral Content ◽  
The Many ◽  
At Home

The Jewish writings of these final years develop themes of the earlier years. Cohen continues to explore one of his favorite topics: the affinity of German and Jewish character. Despite his cosmopolitan conception of Judaism, Cohen still thought that the Jews were most at home in Germany. Yet, despite his belief in the special affinity between Germans and Jews, Cohen still shows his cosmopolitanism by his sympathy for the Ostjuden; he maintains that they should be freed from the many immigration controls imposed on them. Cohen continues to worry about the growing weakening of Jewish communities in Germany, and argues, as Socrates did in the Crito, that people have a special obligation to stay within the communities which nurtured them. In a remarkable 1916 lecture on Plato and the prophets Cohen argues that they are the two major ethical voices in the Western world: Plato gave the West a rational form while the prophets gave it moral content. Cohen now reduces his earlier striving for a unity of religions down to the demand for a unity of conscience.

Scandinavian Thing-steads

Antiquity ◽  
1928 ◽  
Vol 2 (7) ◽  
pp. 328-336
Author(s):  
F. Wildte
Keyword(s):  
Judicial System ◽  
Christian Faith ◽  
The South ◽  
The West ◽  
History Of ◽  
History Of Law ◽  
English Speaking ◽  
The Many ◽  
Judicial Systems

The Scandinavian peoples emerge into the light of history much later than their neighbours in the South and the West, the Teutons on the Continent and in England. It was only through the Viking raids that the Nordic peoples came into touch with the rest of Europe, and were gradually converted to Christianity. Long after the introduction of the Christian faith they preserved many peculiar and archaic traits. Thus the Nordic peoples retained, with great tenacity and conservatism, their ancient judicial system. This system has therefore been the object of considerable interest even outside Scandinavia, although the manuscripts through which it has become known are much later than the corresponding documents of other Teutonic nations.An investigation of the localities where justice was dispensed in former ages is of importance not only for the history of civilization, but also as a complement to the study of oral and written tradition, and thus to the history of law itself. In view of the many points of similarity between the judicial systems of the various Teutonic nations, some notes on the Thing-steads, or places of assembly, in Sweden, Norway, and Denmark, may perhaps be of interest to English-speaking readers.

Lahndā and Lahndī

1930 ◽  
Vol 5 (4) ◽  
pp. 883-887
Author(s):  
George A. Grierson
Keyword(s):  
Separate Entity ◽  
The West ◽  
Independent Form ◽  
The Many

In the Linguistic Survey of India the language spoken in the Western Panjāb is called Lahndā. Previously it had, in India, not been recognized as any independent form of speech, the many local dialects there spoken—Mūltānī, Sirāikī, Hindkī, Jaṭkī, and so on—being looked upon merely as so many dialects of Panjābī. Panjābīs themselves had no general name for this group as a separate entity. When they wished to express that idea they employed a periphrasis, such as Lahndē-dī bōlī, or “ the dialect of the West ”.European scholars, however, had by that time long recognized the fact that a general name for the whole group was needed, and more than forty years ago one of the first describers of the language, Mr. Tisdall, named it “ the Lahindā ”, i.e. Lahndā, “ dialect.” I am not especially enamoured, myself, of this name, but as it had not been challenged for some thirty years, as it was not inconsistent with English idiom, and as no better name had been suggested, I employed it in the Survey.

scholarly journals Distribution, Morphology, Survival, and Genetics of Aspen (Populus Tremuloides) Seedlings Following the 1988 Yellowstone Fires

1996 ◽  
Vol 20 ◽  
pp. 118-122
Author(s):  
Monica Turner ◽  
Rebecca Reed ◽  
William Romme ◽  
Gerald Tuskan
Keyword(s):  
Populus Tremuloides ◽  
Yellowstone National Park ◽  
National Park ◽  
Plant Competition ◽  
Mineral Soil ◽  
Rare Event ◽  
Weather Conditions ◽  
Elevational Gradient ◽  
Quaking Aspen ◽  
Burned Areas

An unexpected consequence of the 1988 Yellowstone fires was the widespread establishment of seedlings of quaking aspen (Populus tremuloides) in the burned forests, including areas outside the previous range of aspen (Kay 1993; Romme et al. 1997). Although aspen is the most widely distributed tree species in North America (Powells 1965), it is relatively uncommon and localized in distribution within Yellowstone National Park (Despain 1991). Most aspen stands in Yellowstone are found in the lower elevation landscapes in the northern portion of the park, and the species was absent - prior to 1988 -- across most of the high plateaus that dominate the southern and central park area. Aspen in the Rocky Mountain region reproduces primarily by means of vegetative root sprouting. Although viable seeds are regularly produced, establishment of seedlings in the wild is apparently a rare event due to the limited tolerance of aspen seedlings for desiccation or competition (e.g., Pearson 1914; McDonough 1985). In the immediate aftermath of the 1988 Yellowstone fires, there was a brief "window of opportunity" for aspen seedling establishment, as a result of abundant aspen seed production, moist weather conditions in spring and summer, and bare mineral soil and reduced plant competition within extensive burned areas (Jelinski and Cheliak 1992; Romme et al. 1997). We initiated this 3-year study in 1996 to address four questions about the aspen seedlings now growing in burned areas across the Yellowstone Plateau: (1) What are the broad-scale patterns of distribution and abundance of aspen seedlings across the subalpine plateaus of Yellowstone National Park? (2) What is the morphology and population structure -- e.g., proportions of genets (genetic individuals that developed from a single seed) and ramets (vegetative root sprouts produced by a genet) of various ages - in aspen seedling populations? (3) What are the mechanisms leading to eventual persistence or extirpation of seedling populations along an elevational gradient, particularly with respect to ungulate browsing and plant competition? (4) What is the genetic diversity and relatedness of the seedling populations along gradients of elevation and substrate?

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