Effective fire suppression in boreal forests

2005 ◽  
Vol 35 (4) ◽  
pp. 772-786 ◽  
Author(s):  
S G Cumming
Keyword(s):  
Boreal Forests ◽  
Regression Models ◽  
Fire History ◽  
Fire Suppression ◽  
Fire Regimes ◽  
Operational Effectiveness ◽  
Logistic Regression Models ◽  
Area Burned ◽  
Large Fires ◽  
Northeastern Alberta

Fire suppression is (functionally) effective insofar as it reduces area burned. In North American boreal forests, fire regimes and historical records are such that this effect cannot be detected or estimated directly. I present an indirect approach, proceeding from the practice of initial attack (IA), which is intended to limit the proportion of "large" fires. I analysed IA's (operational) effectiveness by a controlled retrospective study of fire-history data for an approximately 86 000 km2 region of boreal forest in northeastern Alberta, Canada, from 1968 to 1998 (31 years). Over this interval, various improvements to IA practice, including a 1983 change in management strategy, created a natural experiment. I tested the results with multiple logistic regression models of the annual probabilities of a fire becoming larger than 3 and 200 ha. Annual fire counts (Nt) were a surrogate for fire weather and peak daily counts within years (arrival load). Measured by odds ratios, mean IA effectiveness against 3- and 200-ha fires increased in 1983 by factors of 2.02 (95% CI = 1.70–2.40) and 2.41 (95% CI = 1.69–3.45), respectively. Prior to 1983, the functional response to Nt was consistent with saturation of IA capacity at high arrival loads. From 1983–1998, effectiveness was independent of Nt. I introduce the proportional reduction in area burned (impact) as a measure of functional effectiveness and state conditions under which it can be estimated from the regression models. Over 1983–1998, if suppressed and actual fires were comparable, relative IA impact ([Formula: see text]) was 0.58 (95% CI = 0.34–0.74) and area burned was reduced by 457 500 ha. If fires larger than 1 × 105, 1 × 104, or 1 × 103 ha are assumed to be unpreventable, [Formula: see text] declines to 0.46, 025, or 0.08, respectively, but there is no evidence this is the case.

Fire regimes and their correlates in the Darwin region of northern Australia

2007 ◽  
Vol 13 (3) ◽  
pp. 177 ◽  
Author(s):  
Owen Price ◽  
Bryan Baker
Keyword(s):  
Fire History ◽  
Ad Hoc ◽  
Fire Regime ◽  
Negative Impact ◽  
Fire Suppression ◽  
Landsat Imagery ◽  
Fire Regimes ◽  
Fire Frequency ◽  
Dry Season ◽  
Generalized Linear Modelling

A nine year fire history for the Darwin region was created from Landsat imagery, and examined to describe the fire regime across the region. 43% of the region burned each year, and approximately one quarter of the fires occur in the late dry season, which is lower than most other studied areas. Freehold land, which covers 35% of the greater Darwin region, has 20% long-unburnt land. In contrast, most publicly owned and Aboriginal owned land has very high fire frequency (60-70% per year), and only 5% long unburnt. It seems that much of the Freehold land is managed for fire suppression, while the common land is burnt either to protect the Freehold or by pyromaniacs. Generalized Linear Modelling among a random sample of points revealed that fire frequency is higher among large blocks of savannah vegetation, and at greater distances from mangrove vegetation and roads. This suggests that various kinds of fire break can be used to manage fire in the region. The overall fire frequency in the Darwin region is probably too high and is having a negative impact on wildlife. However, the relatively low proportion of late dry season fires means the regime is probably not as bad as in some other regions. The management of fire is ad-hoc and strongly influenced by tenure. There needs to be a clear statement of regional fire targets and a strategy to achieve these. Continuation of the fire mapping is an essential component of achieving the targets.

Fire Regimes on Andesitic Mountain Terrain in Northeastern Yellowstone-National-Park, Wyoming

1994 ◽  
Vol 4 (2) ◽  
pp. 65 ◽  
Author(s):  
SW Barrett
Keyword(s):  
Yellowstone National Park ◽  
National Park ◽  
Fire History ◽  
Forest Type ◽  
Lodgepole Pine ◽  
Fire Suppression ◽  
Short Interval ◽  
Fire Regimes ◽  
High Elevation ◽  
Forest Community

A fire history investigation was conducted for three forest community types in the Absaroka Mountains of Yellowstone National Park, Wyoming. Master fire chronologies were based on fire-initiated age classes and tree fire scars. The area's major forest type, lodgepole pine (Pinus contorta Dougl. var. latifolia) ecosystems, revealed a predominant pattern of stand replacing fires with a 200 year mean interval-nearly half the length estimated in previous studies of lodgepole pine on less productive subalpine plateaus in YNP. High elevation whitebark pine (P. albicaulis Engelm.) forests had primarily stand replacing fires with >350 year mean intervals, but some stands near timberline also occasionally experienced mixed severity- or non-lethal underburns. Before nearly a century of effective fire suppression in Yellowstone's northern range, lower elevation Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco.) communities adjacent to Artemesia tridentata (Nutt.) grasslands experienced primarily non-lethal underburns at 30 year mean intervals. While short interval fire regimes have been altered by longterm fire suppression, fire exclusion apparently had only limited influence on the area's infrequently burned ecosystems prior to widespread stand replacement burning in 1988.

scholarly journals Effects of large fires on boreal forests of China : historical reconstruction and future prediction through landscape modeling

2020 ◽  
Author(s):  
◽  
Wenru Xu
Keyword(s):  
Remote Sensing ◽  
Species Composition ◽  
Climate Warming ◽  
Boreal Forests ◽  
Fire Regimes ◽  
Forest Recovery ◽  
Burn Severity ◽  
Inventory Data ◽  
Large Fires ◽  
Species Composition And Distribution

Boreal forests of China store about 350 Tg tree biomass carbon, which is approximately 24â€"31 [percent] of the total forest carbon storage in China, and thus, play an important role in maintain national carbon balance. Long-term fire exclusion and climate warming have foster larger and more severe fires. On 1987 May 6, a catastrophic fire, known as the Black Dragon Fire, occurred in this region, and burned 1.3 million ha. This fire is among the top five of such megafires ever recorded in the world, resulting in high degree of tree mortality and reset forest succession stage for most burned stands. Forests have grown back since, with much more homogeneous age classes and composition, which post new ecological risks and challenges. It is predicted that the warming will continue in the next century, and thus uncertainties exist in future fire regimes and vegetation response under novel climate. Chapter II estimate the burn severity and carbon emissions from the Black Dragon fire. I combined field and remote sensing data to map four burn severity classes and calculated combustion efficiency in terms of the biomass immediately consumed in the fire. Results of this chapter showed that 1.30 million hectares burned and 52 [percent] of that area burned with high severity. The emitted carbon dioxide equivalents (CO2e), accounted for approximately 10 [percent] of total fossil fuel emissions from China in 1987, along with CO (2 [percent] - 3 [percent] of annual anthropogenic CO emissions from China) and non-methane hydrocarbons (NMHC) contributing to the atmospheric pollutants. This study provides an important basis for carbon emission estimation and understanding the impacts of megafires. Chapter III developed a novel framework to spatially reconstruct the post-fire time-series of forest conditions after the 1987 Black Dragon fire of China by integrating a forest landscape model (LANDIS) with remote sensing and inventory data. I derived pre-fire (1985) forest composition and the megafire perimeter and severity using remote sensing and inventory data. I simulated the megafire and the post-megafire forest recovery from 1985-2015 using the LANDIS model. I calibrated the model and validated the simulation results using inventory data. I demonstrated that the framework was effective in reconstructing the post-fire stand dynamics and that it is applicable to other types of disturbances. Chapter IV investigated the effects of future fire regimes on boreal forests of China under a warming climate. I simulated species composition and distribution changes to the year 2100 using a coupled forest dynamic model (LANDIS PRO) and ecosystem process model (LINKAGES). I focused on two possible fire regimes (frequent small fires and infrequent large fires). Results of this chapter showed that climate warming and fires strongly affected tree species composition and distribution in the boreal forests of China. Climate warming promoted transitions from boreal species to pioneer and temperate species. Fire effects acted in the same direction as climate change effects on species occurrences, thereby catalyzing climate-induced transitions. Frequent small fires exerted stronger effects on the species composition shifts than infrequent large fires. The combined effects of climate warming and fire on the shifts in species composition will accumulate through time and space and can induce a complete transition of forest type, and alter forest dynamics and functions.

A 560-Year Record of Santa Ana Fires Reconstructed from Charcoal Deposited in the Santa Barbara Basin, California

1999 ◽  
Vol 51 (3) ◽  
pp. 295-305 ◽  
Author(s):  
Scott A. Mensing ◽  
Joel Michaelsen ◽  
Roger Byrne
Keyword(s):  
Fire History ◽  
Fire Regime ◽  
Fire Suppression ◽  
Strong Relationship ◽  
Fire Control ◽  
Santa Barbara ◽  
Santa Barbara Basin ◽  
Santa Ana ◽  
Active Fire ◽  
Large Fires

AbstractMicroscopic charcoal from varved Santa Barbara Basin sediments was used to reconstruct a 560-yr record (A.D. 1425 to 1985) of Santa Ana fires. Comparison of large (>3750 μm2) charcoal with documented fire records in the Santa Barbara Ranger District shows that high accumulations correspond to large fires (>20,000 ha) that occurred during Santa Ana conditions. The charcoal record reconstructed a minimum of 20 large fires in the Santa Barbara region during the study period. The average time between fires shows no distinct change across three different land use periods: the Chumash period, apparently characterized by frequent burning, the Spanish/Early American period with nominal fire control, and the 20th century with active fire suppression. Pollen data support the conclusion that the fire regime has not dramatically changed during the last 500 yr. Comparison of large charcoal particle accumulation rates and precipitation reconstructed from tree rings show a strong relationship between climate and fire history, with large fires consistently occurring at the end of wet periods and the beginning of droughts.

The history and pattern of fire in the boreal forest of southeastern Labrador

1983 ◽  
Vol 61 (9) ◽  
pp. 2459-2471 ◽  
Author(s):  
David R. Foster
Keyword(s):  
Boreal Forest ◽  
Fire History ◽  
Fire Regimes ◽  
Strongly Correlated ◽  
History Of ◽  
Large Fires ◽  
Modern Landscape ◽  
Fire Incidence ◽  
Topographic Relief ◽  
Birch Forests

The fire history of the wilderness of southeastern Labrador is marked by a patchy distribution of large fires in time and space. During the 110-year period encompassed by this study, major fires occurred in four decades, 1870–1879, 1890–1899, 1950–1959, 1970–1979. From 1900 to 1951 only 1125 km2 burned; this represents approximately 10% of the total area consumed from 1870 to 1980. Fire records indicate an asynchroneity of the important fire years in southeastern Labrador and adjacent provinces and within Labrador itself. This observation suggests that the meteorological conditions controlling fire occurrence in this portion of the eastern boreal forest are local in nature and extent. The fire rotation for southeastern Labrador is calculated at approximately 500 years, significantly longer than that estimated for other regions of boreal forest. The rare occurrence of large fires is explained by high levels of precipitation and by the preponderance of fire breaks, primarily lakes and peatlands. On the basis of physiographic criteria the region is subdivided into two types of landscape displaying contrasting fire regimes. The large interior plateau, which is covered by extensive peatlands and numerous lakes, has a low fire incidence and extremely long fire rotation. In contrast, large fires are common in the watersheds of the Alexis, Paradise, and St. Augustin rivers where the topographic relief is quite varied and peatlands are scarce. The regional pattern of fire activity has important phytogeographical implications. The lichen woodlands and birch forests are fire-dependent vegetation types; their distribution in the modern landscape is strongly correlated with the historical occurrence of fire during the past 110 years. In addition it is postulated that the historical absence of fire across the large plains in southeastern Labrador has contributed to the development of extensive peatlands in these areas.

Large fires, fire effects and the fire-regime concept

2008 ◽  
Vol 17 (6) ◽  
pp. 688 ◽  
Author(s):  
A. Malcolm Gill ◽  
Grant Allan
Keyword(s):  
Prescribed Burning ◽  
Fire Regime ◽  
Fire Suppression ◽  
Wide Spectrum ◽  
Current Trend ◽  
Fire Regimes ◽  
Fire Effects ◽  
Spatial Variables ◽  
Historical Series ◽  
Large Fires

‘Large’ fires may be declared so because of their absolute or relative area. Huge fires – with areas of more than 106 ha (104 km2) have occurred across a wide spectrum of Australian environments and are known on other continents. Such large fires are rare whereas fires with much smaller areas are common. Large fires are initiated by single or multiple ignitions and become large because of some combination of: rapid rates of spread; long ‘life’; merging, and failure of initial suppression operations. Fires as ecological ‘events’ occur within a ‘regime’ – an historical series. Both events and regimes have effects that may be discerned in terms of water, land, air or organisms. What have been regarded as the components of ‘regimes’ have differed between observers, the main issue being whether or not spatial variables need to be included; ‘area’ involvement is briefly addressed. The current trend toward fire-regime control through fuel treatment, including management (prescribed) burning, and fire suppression may be expected to continue. These trends, among others, can be expected to change fire regimes. What is regarded as ‘large’ among fires may change as the planet becomes increasingly human-dominated.

Stratigraphic Charcoal Analysis on Petrographic Thin Sections: Application to Fire History in Northwestern Minnesota

1988 ◽  
Vol 30 (1) ◽  
pp. 81-91 ◽  
Author(s):  
James S. Clark
Keyword(s):  
Lake Sediments ◽  
Fire History ◽  
Fire Regime ◽  
Fire Suppression ◽  
Fire Regimes ◽  
Charcoal Analysis ◽  
Fire Scars ◽  
Good Correspondence ◽  
Thin Sections ◽  
Fire Scar

Results of stratigraphic charcoal analysis from thin sections of varved lake sediments have been compared with fire scars on red pine trees in northwestern Minnesota to determine if charcoal data accurately reflect fire regimes. Pollen and opaque-spherule analyses were completed from a short core to confirm that laminations were annual over the last 350 yr. A good correspondence was found between fossil-charcoal and fire-scar data. Individual fires could be identified as specific peaks in the charcoal curves, and times of reduced fire frequency were reflected in the charcoal data. Charcoal was absent during the fire-suppression era from 1920 A.D. to the present. Distinct charcoal maxima from 1864 to 1920 occurred at times of fire within the lake catchment. Fire was less frequent during the 19th century, and charcoal was substantially less abundant. Fire was frequent from 1760 to 1815, and charcoal was abundant continuously. Fire scars and fossil charcoal indicate that fires did not occur during 1730–1750 and 1670–1700. Several fires occurred from 1640 to 1670 and 1700 to 1730. Charcoal counted from pollen preparations in the area generally do not show this changing fire regime. Simulated “sampling” of the thin-section data in a fashion comparable to pollen-slide methods suggests that sampling alone is not sufficient to account for differences between the two methods. Integrating annual charcoal values in this fashion still produced much higher resolution than the pollen-slide method, and the postfire suppression decline of charcoal characteristic of my method (but not of pollen slides) is still evident. Consideration of the differences in size of fragments counted by the two methods is necessary to explain charcoal representation in lake sediments.

scholarly journals Medieval warming initiated exceptionally large wildfire outbreaks in the Rocky Mountains

2015 ◽  
Vol 112 (43) ◽  
pp. 13261-13266 ◽  
Author(s):  
W. John Calder ◽  
Dusty Parker ◽  
Cody J. Stopka ◽  
Gonzalo Jiménez-Moreno ◽  
Bryan N. Shuman
Keyword(s):  
Fire Regimes ◽  
Vegetation Changes ◽  
Western North America ◽  
Medieval Climate Anomaly ◽  
Climate Anomaly ◽  
Us History ◽  
Area Burned ◽  
The Past ◽  
Median Estimate ◽  
Large Fires

Many of the largest wildfires in US history burned in recent decades, and climate change explains much of the increase in area burned. The frequency of extreme wildfire weather will increase with continued warming, but many uncertainties still exist about future fire regimes, including how the risk of large fires will persist as vegetation changes. Past fire-climate relationships provide an opportunity to constrain the related uncertainties, and reveal widespread burning across large regions of western North America during past warm intervals. Whether such episodes also burned large portions of individual landscapes has been difficult to determine, however, because uncertainties with the ages of past fires and limited spatial resolution often prohibit specific estimates of past area burned. Accounting for these challenges in a subalpine landscape in Colorado, we estimated century-scale fire synchroneity across 12 lake-sediment charcoal records spanning the past 2,000 y. The percentage of sites burned only deviated from the historic range of variability during the Medieval Climate Anomaly (MCA) between 1,200 and 850 y B.P., when temperatures were similar to recent decades. Between 1,130 and 1,030 y B.P., 83% (median estimate) of our sites burned when temperatures increased ∼0.5 °C relative to the preceding centuries. Lake-based fire rotation during the MCA decreased to an estimated 120 y, representing a 260% higher rate of burning than during the period of dendroecological sampling (360 to −60 y B.P.). Increased burning, however, did not persist throughout the MCA. Burning declined abruptly before temperatures cooled, indicating possible fuel limitations to continued burning.

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

2001 ◽  
Vol 31 (8) ◽  
pp. 1467-1480 ◽  
Author(s):  
P C Ward ◽  
A G Tithecott ◽  
B M Wotton
Keyword(s):  
Fire History ◽  
Fire Management ◽  
Forest Disturbance ◽  
Fire Suppression ◽  
Fire Disturbance ◽  
Fire Size ◽  
Area Burned ◽  
Return Interval ◽  
The Past ◽  
Northwestern Ontario

Ward and Tithecott (P.C. Ward and A.G. Tithecott. 1993. Ontario Ministry of Natural Resources, Aviation, Flood and Fire Management Branch, Publ. 305) presented data that indicated fire suppression activities in Ontario led to reductions in average annual area burned and greater numbers of small fires, compared with what would have been observed in the absence of suppression. Miyanishi and Johnson (K. Miyanishi and E.A. Johnson. 2001. Can. J. For. Res. 31: 1462–1466) have questioned aspects of that report, suggesting that the evidence does not demonstrate that suppression influences fire size or frequency. Fire-history studies in Ontario's forests and recent fire disturbance records do show that the fire-return interval has lengthened considerably in Ontario's protected forest since pre-suppression times. Analysis of forest inventory age-class distributions also reflect a reduction in overall forest disturbance rates in the past 40 years. Average annual burn fractions (ABF) calculated for protected and unprotected forests in northwestern Ontario for the period 1976-2000 show an ABF of 1.11% in the unprotected forest and only 0.34% in the protected forest. There is clear evidence that fire suppression in Ontario contains many fires at small sizes that would have otherwise grown to larger sizes, and reduces the overall average annual area burned in the protected forest.

Fire-regime changes in Canada over the last half century

2019 ◽  
Vol 49 (3) ◽  
pp. 256-269 ◽  
Author(s):  
Chelene C. Hanes ◽  
Xianli Wang ◽  
Piyush Jain ◽  
Marc-André Parisien ◽  
John M. Little ◽  
...  
Keyword(s):  
Fire Regime ◽  
Fire Regimes ◽  
Fire Season ◽  
Western Canada ◽  
Half Century ◽  
Regime Changes ◽  
Area Burned ◽  
Active Fire ◽  
Large Fires ◽  
In Fire

Contemporary fire regimes of Canadian forests have been well documented based on forest fire records between the late 1950s to 1990s. Due to known limitations of fire datasets, an analysis of changes in fire-regime characteristics could not be easily undertaken. This paper presents fire-regime trends nationally and within two zonation systems, the homogeneous fire-regime zones and ecozones, for two time periods, 1959–2015 and 1980–2015. Nationally, trends in both area burned and number of large fires (≥200 ha) have increased significantly since 1959, which might be due to increases in lightning-caused fires. Human-caused fires, in contrast, have shown a decline. Results suggest that large fires have been getting larger over the last 57 years and that the fire season has been starting approximately one week earlier and ending one week later. At the regional level, trends in fire regimes are variable across the country, with fewer significant trends. Area burned, number of large fires, and lightning-caused fires are increasing in most of western Canada, whereas human-caused fires are either stable or declining throughout the country. Overall, Canadian forests appear to have been engaged in a trajectory towards more active fire regimes over the last half century.

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