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.

scholarly journals Variation in fire scar phenology from mixed conifer trees in the Sierra Nevada

2018 ◽  
Vol 48 (1) ◽  
pp. 101-104 ◽  
Author(s):  
Scott L. Stephens ◽  
Liam Maier ◽  
Lilah Gonen ◽  
Jennifer D. York ◽  
Brandon M. Collins ◽  
...  
Keyword(s):  
Sierra Nevada ◽  
Fire History ◽  
Fire Regimes ◽  
Fire Season ◽  
Mixed Conifer ◽  
Outer Bark ◽  
Individual Tree ◽  
Fire Scar ◽  
The Individual ◽  
In Fire

Fire scar based studies have provided robust reconstructions of past fire regimes. The season in which a fire occurs can have considerable impacts to ecosystems but inference on seasonality from fire scars is relatively uncertain. This study examined patterns in the phenology of cambium formation and wounding responses in the five common mixed conifer tree species of the Sierra Nevada. The outer bark was shaved on 35 trees and individual locations within the shaved portions were wounded systematically by applying direct heat using a handheld torch. Most of the trees had not commenced annual ring development by the first burning treatment in late May. By the second treatment, scars were identified mostly within the early or middle earlywood, although variation was high compared with other treatment periods. By late October, all scars were recorded at the ring boundary. Although intra-ring scar positions generally followed a logical temporal pattern, there was high tree to tree variation such as Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) burned on 26 June induced scars in the early, mid, and late earlywood depending on the individual tree. This high variation makes it somewhat challenging to precisely assign past fire season to published fire history studies.

scholarly journals Fire history in the Araucaria araucana forests of Argentina: human and climate influences

2013 ◽  
Vol 22 (2) ◽  
pp. 194 ◽  
Author(s):  
I. A. Mundo ◽  
T. Kitzberger ◽  
F. A. Roig Juñent ◽  
R. Villalba ◽  
M. D. Barrera
Keyword(s):  
Human Activities ◽  
Fire History ◽  
Southern Oscillation ◽  
Fire Regimes ◽  
Southern Annular Mode ◽  
Temporal Variations ◽  
La Niña ◽  
La Nina ◽  
Araucaria Araucana ◽  
Climate Influences

Little is known about drivers and trends of historic fire regimes in the Araucaria araucana forests of south-western Argentina. Fire history in these forests was reconstructed by the analysis of 246 fire-scarred partial cross-sections from this fire-resistant tree collected at 10 sites in Neuquén, northern Patagonia. Fire chronologies showed an increase in fire occurrence during the nineteenth century and a sharp decrease since the early twentieth century. The creation of Lanín National Park in 1937, the change in human activities, and the active suppression of wildfires led to a significant increase in mean fire intervals since 1930. In addition to these multidecadal to centennial scale drives of fire frequency, interannual variability in wildfire activity was associated with El Niño–Southern Oscillation. Years of widespread fire are related to negative departures of both Niño 3.4 and Pacific Decadal Oscillation indexes (i.e. La Niña conditions), as well as coincident phases of positive Southern Annular Mode and La Niña events. Temporal variations in the Araucaria fire history in Argentina clearly show the combined effect of human and climate influences on fire regimes. A comparison with previous fire history studies in the Araucaria forests of Chile reveals substantial differences related to differences in human activities on both sides of the Andes and the earlier implementation of protected areas in Argentina.

The influences of drought and humans on the fire regimes of northern Pennsylvania, USA

2013 ◽  
Vol 43 (8) ◽  
pp. 757-767 ◽  
Author(s):  
Patrick H. Brose ◽  
Daniel C. Dey ◽  
Richard P. Guyette ◽  
Joseph M. Marschall ◽  
Michael C. Stambaugh
Keyword(s):  
American Indians ◽  
Cross Sections ◽  
Prescribed Fire ◽  
Fire History ◽  
Fire Regime ◽  
Fire Regimes ◽  
European Settlement ◽  
Pine Regeneration ◽  
Fire Exclusion ◽  
Dormant Season

Understanding past fire regimes is necessary to justify and implement restoration of disturbance-associated forests via prescribed fire programs. In eastern North America, the characteristics of many presettlement fire regimes are unclear because of the passage of time. To help clarify this situation, we developed a 435-year fire history for the former conifer forests of northern Pennsylvania. Ninety-three cross sections of fire-scarred red pines (Pinus resinosa Aiton) collected from three sites were analyzed to determine common fire regime characteristics. Prior to European settlement, fires occurred every 35–50 years and were often large dormant-season burns that sometimes initiated red pine regeneration. American Indians probably ignited these fires. Fire occurrence had a weak association with multiyear droughts. After European settlement started around 1800, fires occurred every 5–7 years due to widespread logging. Fire size and seasonality expanded to include small growing-season fires. The weak drought–fire association ceased. In the early 1900s, logging ended and wildfire control began. Since then, fires have been nearly absent from the sites despite several multiyear droughts in the 20th century. The human influences of cultural burning, logging, and fire exclusion are more important than the influence of drought to the fire regimes of northern Pennsylvania.

Critical live fuel moisture in chaparral ecosystems: a threshold for fire activity and its relationship to antecedent precipitation

2009 ◽  
Vol 18 (8) ◽  
pp. 1021 ◽  
Author(s):  
Philip E. Dennison ◽  
Max A. Moritz
Keyword(s):  
Los Angeles ◽  
Fire History ◽  
Regression Tree ◽  
Fire Regimes ◽  
Winter Precipitation ◽  
Fire Season ◽  
Climate Change Scenarios ◽  
Fuel Moisture ◽  
Spring Precipitation ◽  
Live Fuel Moisture

Large wildfires in southern California typically occur during periods of reduced live fuel moisture (LFM) and high winds. Previous work has found evidence that a LFM threshold may determine when large fires can occur. Using a LFM time series and a fire history for Los Angeles County, California, we found strong evidence for a LFM threshold near 79%. Monthly and 3-month total precipitation data were used to show that the timing of this threshold during the fire season is strongly correlated with antecedent rainfall. Spring precipitation, particularly in the month of March, was found to be the primary driver of the timing of LFM decline, although regression tree analysis revealed that high winter precipitation may delay the timing of the threshold in some years. This work further establishes relationships between precipitation and fire potential that may prove important for anticipating shifts in fire regimes under climate-change scenarios.

Fire history of a naturally fragmented landscape in central Oregon

2006 ◽  
Vol 36 (5) ◽  
pp. 1108-1120 ◽  
Author(s):  
Karen B Arabas ◽  
Keith S Hadley ◽  
Evan R Larson
Keyword(s):  
Fire History ◽  
Fire Regimes ◽  
Spatial Arrangement ◽  
Fire Spread ◽  
Fragmented Landscape ◽  
Isolation Index ◽  
Fire Exclusion ◽  
History Of ◽  
Historical Agency ◽  
In Fire

We examined the fire history of 11 forest isolates surrounded by lava flows (kipukas) in central Oregon to determine historical differences in fire regimes between kipukas and the surrounding forest, and the role of spatial and environmental variables in fire occurrence. Tree-ring analysis and statistical comparisons show that historical agency records underestimate the number of fires based on the incidence of fire scars. Fires occurred more frequently on kipukas, were typically smaller, and were predominantly lightning-initiated. Except for three widespread fires, fires on kipukas and in the surrounding forest were largely asynchronous. The mean fire-return interval (MFRI) in the surrounding forest decreased following Euro-American settlement and increased on the kipukas with spot-fire removal. This suggests either that forest management and fire exclusion in the surrounding forest decreased fire spread to the kipukas, or that most fires originated on the kipukas. MFRI correlates strongly with distance to the nearest kipuka and a distance-weighted isolation index. The number of fires correlates with elevation change and distance to the nearest kipuka. Fire in naturally fragmented landscapes is influenced by the spatial arrangement of patches, environmental conditions, and human activities. Reconstructing fire histories from forest isolates in the context of their mainland counterparts may have methodological advantages and theoretical implications for forested landscapes characterized by human-imposed insularity.

Holocene fire history reconstruction of a mid-elevation mixed-conifer forest in the Eastern Cascades, Washington (USA)

The Holocene ◽  
2021 ◽  
pp. 095968362098803
Author(s):  
Zoe A Rushton ◽  
Megan K Walsh
Keyword(s):  
Fire History ◽  
Fire Regime ◽  
Fire Severity ◽  
Fire Regimes ◽  
Conifer Forest ◽  
Mixed Conifer ◽  
The Past ◽  
Mixed Conifer Forest ◽  
Fire Activity ◽  
Eastern Cascades

Fire histories of mid-elevation mixed-conifer forests are uncommon in the eastern Cascades, limiting our understanding of long-term fire dynamics in these environments. The purpose of this study was to reconstruct the fire and vegetation history for a moist mid-elevation mixed-conifer site, and to determine whether Holocene fire activity in this watershed was intermediate to fire regimes observed at higher and lower elevations in the eastern Cascades. Fire activity and vegetation change was reconstructed using macroscopic charcoal and pollen analysis of sediment core from Long Lake. This site is located ~45 km west of Yakima, WA, and exists in a grand fir-dominated, mixed-conifer forest. Results show low fire activity from ca. 9870 to 6000 cal yr BP, after which time fire increased and remained frequent until ca. 500 cal yr BP. A woodland environment existed at the site in the early Holocene, with the modern coniferous forest establishing ca. 6000–5500 cal yr BP. A mixed-severity fire regime has existed at the site for the past ~6000 years, with both higher- and lower-severity fire episodes occurring on average every ~80–100 years. However, only one fire episode occurred in the Long Lake watershed during the past 500 years, and none within the past ~150 years. Based on a comparison with other eastern Cascade sites, Holocene fire regimes at Long Lake, particularly during the late Holocene, appear to be intermediate between those observed at higher- and lower elevation sites, both in terms of fire severity and frequency.

Vegetation responses to fire history and soil properties in grazed semi-arid tropical savanna

2018 ◽  
Vol 40 (3) ◽  
pp. 271 ◽  
Author(s):  
Gabrielle Lebbink ◽  
Rod Fensham ◽  
Robyn Cowley
Keyword(s):  
Soil Properties ◽  
Fire History ◽  
Fire Regimes ◽  
Fire Season ◽  
Individual Plant ◽  
Vegetation Composition ◽  
Mixed Effect ◽  
Total Species Richness ◽  
Floristic Patterns ◽  
Semi Arid

A long-term (1993–2016) fire experiment in the grazed semi-arid savanna of the Northern Territory was used to investigate the relative impacts of soil properties and fire history on vegetation composition and diversity in grassland and woodland habitats. Subtle variation in soil texture influenced vegetation composition and abundance independently of fire variables and was generally a more important control on floristic patterns. Total species richness, lifeform richness and the abundance and presence of many individual plant species declined with increasing clay content. Linear mixed effect models with combined habitat data, showed total richness and richness of annual and perennial forbs, annual grasses and legumes increased with more frequent fire. Perennial grass abundance and richness was not influenced by fire. Total and lifeform mean richness did not vary between two and four yearly or early and late burnt treatments. Richness and abundance was generally significantly higher on burnt blocks than unburnt blocks regardless of fire season or interval. These results suggest greater diversity after burning is a result of an increase in ephemeral species. However, the overall influence of fire on floristic patterns is relatively moderate and fire regimes may therefore be manipulated for other management imperatives, such as fauna conservation, carbon sequestration and pastoral productivity without substantial impacts on botanical values in semi-arid tropical savannas.

Pathways for climate change effects on fire: Models, data, and uncertainties

2011 ◽  
Vol 35 (3) ◽  
pp. 393-407 ◽  
Author(s):  
Amy E. Hessl
Keyword(s):  
Climate Change ◽  
Fire History ◽  
Wildland Fire ◽  
Fire Severity ◽  
Empirical Studies ◽  
Large Body ◽  
Fire Regimes ◽  
Area Burned ◽  
Frequency Changes ◽  
In Fire

Fire is a global process affecting both the biosphere and the atmosphere. As a result, measuring rates of change in wildland fire and understanding the mechanisms responsible for such changes are important research goals. A large body of modeling studies projects increases in wildfire activity in future decades, but few empirical studies have documented change in modern fire regimes. Identifying generalizable pathways through which climate change may alter fire regimes is a critical next step for understanding, measuring, and modeling fire under a changing climate. In this progress report, I review recent model-, empirical-, and fire history-based studies of fire and climate change and propose three pathways along which fire regimes might respond to climate change: changes in fuel condition, fuel volume, and ignitions. Model- and empirical-based studies have largely focused on changes in fuel condition with some models projecting up to 50% increases in area burned under a 2 x CO2 climate. Fire history data derived from tree-rings, sediment charcoal, and soil charcoal have helped identify past trajectories of change in fire regimes and can point to possible future conditions. However, most fire history research has focused on changes in area burned and fire frequency. Changes in fire severity may be equally important for the earth system and require further attention. Critical research needs include next generation dynamic vegetation models (DGVMs) that consider changes in vegetation alongside changes in human activities and long fire history records from a variety of vegetation types suitable for validating these DGVMs.

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.

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