Accurate estimation of mean fire interval for managing fire

2006 ◽  
Vol 15 (4) ◽  
pp. 489 ◽  
Author(s):  
Xiaojun Kou ◽  
William L. Baker
Keyword(s):  
Fire History ◽  
Fire Regimes ◽  
New Method ◽  
Tree Age ◽  
Accurate Estimation ◽  
Individual Tree ◽  
Interval Method ◽  
Population Mean ◽  
Fire Scar ◽  
Mean Fire Interval

Accurate fire-history data are needed if local management of fire or costly national plans for restoring and managing fire and forest structure are to succeed. Fire-history researchers often use fire scars and the composite fire interval method to reconstruct parameters of past fire regimes, such as the population mean fire interval, but the composite method has serious limitations. We modified an alternative non-composite fire interval method, the individual-tree fire-interval method, to derive a more accurate new method, the all-tree fire-interval method. A stochastic fire-scar generating model to assess the accuracy of the new method and its predecessors was then used. Three factors (scarring ratio, population mean fire interval, and tree age) that affect accuracy were varied in the model runs. More complexity (trees with varied scarring ratio between the first scar and successive scars) also was modelled to test the robustness of the method. The all-tree fire-interval method was shown to greatly improve accuracy and provide unbiased estimates of the population mean fire interval. The method also produced encouraging results when scarring was more complex. The new all-tree fire-interval method will require further research on the rates at which trees are scarred by fire, but this would be generally beneficial to understanding fire history.

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.

Spatial interpolation and mean fire interval analyses quantify historical mixed-severity fire regimes

2017 ◽  
Vol 26 (2) ◽  
pp. 136 ◽  
Author(s):  
Gregory A. Greene ◽  
Lori D. Daniels
Keyword(s):  
Fire Regimes ◽  
Spatial Modelling ◽  
Sensitivity Analyses ◽  
Tree Age ◽  
Fire Scars ◽  
Fire Scar ◽  
Distance Weighted ◽  
Mean Fire Interval ◽  
Fire Intervals ◽  
Inverse Distance

Tree-age data in combination with fire scars improved inverse-distance-weighted spatial modelling of historical fire boundaries and intervals for the Darkwoods, British Columbia, Canada. Fire-scarred trees provided direct evidence of fire. The presence of fire-sensitive trees at sites with no fire scars indicated fire-free periods over their lifespan. Sensitivity analyses showed: (1) tree ages used in combination with fire-scar dates refined fire boundaries without biasing mean fire return intervals; and (2) compared with derived conservative, moderate and liberal thresholds (i.e. minimum burn likelihood cut-off values), fixed thresholds generated area burned estimates that were most consistent with estimates based on the proportion of plots that recorded historical fires. Unweighted and weighted spatial mean fire intervals (50–56 and 58–68 years respectively) exceeded dendrochronological plot-level (38-year) estimates based on fire scars only. Including tree-age data from fire-sensitive trees to calculate landscape-level fire interval metrics lengthened the mean return intervals, better representing historical high-severity fires. Supplementing fire scars with tree ages better reflects the spatiotemporal diversity of fire frequencies and severities inherent to mixed-severity fire regimes.

Anthropogenic impact on past and present fire regimes in a boreal forest landscape of southeastern Norway

2005 ◽  
Vol 35 (11) ◽  
pp. 2719-2726 ◽  
Author(s):  
Rune Groven ◽  
Mats Niklasson
Keyword(s):  
Fire History ◽  
Nature Reserve ◽  
Fire Regimes ◽  
Mining Activity ◽  
Forest Landscape ◽  
Sample Mean ◽  
History Of ◽  
Mean Fire Interval ◽  
Fire Intervals ◽  
Historical Accounts

Fire-scarred wood samples from 50 stumps, snags, and living trees of Scots pine (Pinus sylvestris L.) were dendrochronologically cross-dated to describe an 800 year long fire history of Eldferdalen Nature Reserve (~6 ha) and its surroundings (~4000 ha) in southeastern Norway. In the western part of the study area, we recorded 55 different fires within a 200 ha area around the reserve between 1511 and 1759 and a mean fire interval in single samples of 24.6 years. The composite mean fire interval for the nature reserve was 10.5 years. Fire intervals were longer in the eastern part of the study area, with a single sample mean fire interval of 49.1 years. Only three fires were detected after 1759, the last one in 1822. Based on historical accounts, we assume that the high number of fires and short fire intervals were influenced by deliberate ignition for agricultural purposes, most likely burning to improve the conditions for cattle grazing and slash-and-burn cultivation. We suggest that the cessation of fires was influenced by the increased value of timber and mining activity, thereby leading to increased interest in conservation of the timber resources.

Fire history and forest structure of an endangered subtropical ecosystem in the Florida Keys, USA

2013 ◽  
Vol 22 (3) ◽  
pp. 394 ◽  
Author(s):  
Grant L. Harley ◽  
Henri D. Grissino-Mayer ◽  
Sally P. Horn
Keyword(s):  
Fire History ◽  
Management Practices ◽  
Fire Management ◽  
Stand Structure ◽  
Florida Keys ◽  
Fire Regimes ◽  
Pinus Elliottii ◽  
South Florida ◽  
Prescribed Burns ◽  
Fire Scar

We focussed on the influence of historical fire and varied fire management practices on the structure of globally endangered pine rockland ecosystems on two adjacent islands in the Florida Keys: Big Pine Key and No Name Key. We reconstructed fire history in two stands from fire scars on South Florida slash pines (Pinus elliottii Engelm. var. densa Little & Dor.) that were accurately dated using dendrochronology, and quantified stand structure to infer successional trajectories. Fire regimes on Big Pine Key and No Name Key over the past 150 years differed in fire return interval and spatial extent. Fire scar analysis indicated that fires burnt at intervals of 6 and 9 years (Weibull median probability interval) on Big Pine Key and No Name Key with the majority of fires occurring late in the growing season. On Big Pine Key, pine recruitment was widespread, likely due to multiple, widespread prescribed burns conducted since 2000. No Name Key experienced fewer fires than Big Pine Key, but pines recruited at the site from at least the 1890s through the 1970s. Today, pine recruitment is nearly absent on No Name Key, where fire management practices since 1957 could result in loss of pine rockland habitat.

Fire History and Tree Recruitment in an Uncut New England Forest

1994 ◽  
Vol 42 (2) ◽  
pp. 206-215 ◽  
Author(s):  
Daniel H. Mann ◽  
F.Brett Engstrom ◽  
Jill L. Bubier
Keyword(s):  
New England ◽  
Fire History ◽  
Fire Frequency ◽  
Tree Age ◽  
Fuel Load ◽  
Summer Drought ◽  
Climate History ◽  
Fire Scar ◽  
15Th Century ◽  
Dead Trees

AbstractFire and forest histories in a hemlock-pine forest in Vermont have been reconstructed by dating fire scars and reconstructing the age distributions of living and dead trees. The ages of living red pines, white pines, and hemlocks show that most of the present forest germinated after a series of spatially overlapping fires between A.D. 1790 and 1850. The ages of cross-dated, dead red pines indicate that this was the third major recruitment interval for pines in this forest since ca. A.D. 1450. We interpret the fire scar and tree age data as recording ca. 50-yr intervals of increased fire frequency recurring every 100-200 yr in response to accumulating fuel loads that coincide with summer drought. The historical records of fires and tree ages, together with the present fuel load, suggest that the next interval of stand-regenerating fires is now overdue. Our success in cross-dating the remnants of dead red pines as old as the 15th century A.D. holds promise for extending reconstructions of fire, forest, and climate history in other parts of this tree's range.

scholarly journals Fire History (1896–2013) in an Abies religiosa Forest in the Sierra Norte of Puebla, Mexico

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 700
Author(s):  
Julián Cerano-Paredes ◽  
Dante A. Rodríguez-Trejo ◽  
José M. Iniguez ◽  
Rosalinda Cervantes-Martínez ◽  
José Villanueva-Díaz ◽  
...  
Keyword(s):  
Fire History ◽  
Southern Oscillation ◽  
Ring Width ◽  
Fire Regimes ◽  
Drought Severity ◽  
Past Century ◽  
Fire Scars ◽  
Fire Scar ◽  
Management Actions ◽  
Abies Religiosa

The oyamel forests, as Abies dominated forests are commonly known as, register their largest distribution (95% of their population) along the Trans-Mexican Volcanic Belt (TMVB). Although efforts have been made to study these forests with various approaches, dendrochronology-based studies have been limited, particularly in pure Abies forests in this region. The objective of this study was to reconstruct fire regimes in an Abies religiosa forest in the Sierra Norte in the state of Puebla, Mexico. Within an area of 50-ha, we collected 40 fire-scar samples, which were processed and analyzed using dendrochronological techniques to identify 153 fire scars. The fire history was reconstructed for a period of 118 years (1896–2013), with low severity surface fires occurring mainly during in the spring (92.8%) and summer (7.2%). Over the past century, fires were frequent, with an mean fire interval (MFI) and Weibull median probability of (WMPI) of five years when considering all fire scars and less than 10 years for fires covering larger areas (fires recorded by ≥25% of samples). Extensive fires were synchronized with drought conditions based on Ring Width Indexes, Palmer Drought Severity Index (PDSI) and El Niño Southern Oscillation (ENSO). After 1983, we observed a change in fire frequencies attributed to regulated management. Longer fire intervals within the last several decades are likely leading to increased fuel accumulations and could potentially result in more severe fires in the future, threatening the sustainability of these forests. Based on our finding, we recommend management actions (silvicultural or prescribed fire) to reduce fuels and the risk of severe fires, particularly in the face of climatic changes.

scholarly journals Uncertainty in surface-fire history: the case of ponderosa pine forests in the western United States

2001 ◽  
Vol 31 (7) ◽  
pp. 1205-1226 ◽  
Author(s):  
William L Baker ◽  
Donna Ehle
Keyword(s):  
United States ◽  
Forest Structure ◽  
Ponderosa Pine ◽  
Fire History ◽  
Pine Forests ◽  
Western United States ◽  
Surface Fire ◽  
Population Mean ◽  
Ponderosa Pine Forests ◽  
Fire Scar

Present understanding of fire ecology in forests subject to surface fires is based on fire-scar evidence. We present theory and empirical results that suggest that fire-history data have uncertainties and biases when used to estimate the population mean fire interval (FI) or other parameters of the fire regime. First, the population mean FI is difficult to estimate precisely because of unrecorded fires and can only be shown to lie in a broad range. Second, the interval between tree origin and first fire scar estimates a real fire-free interval that warrants inclusion in mean-FI calculations. Finally, inadequate sampling and targeting of multiple-scarred trees and high scar densities bias mean FIs toward shorter intervals. In ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.) forests of the western United States, these uncertainties and biases suggest that reported mean FIs of 2-25 years significantly underestimate population mean FIs, which instead may be between 22 and 308 years. We suggest that uncertainty be explicitly stated in fire-history results by bracketing the range of possible population mean FIs. Research and improved methods may narrow the range, but there is no statistical or other method that can eliminate all uncertainty. Longer mean FIs in ponderosa pine forests suggest that (i) surface fire is still important, but less so in maintaining forest structure, and (ii) some dense patches of trees may have occurred in the pre-Euro-American landscape. Creation of low-density forest structure across all parts of ponderosa pine landscapes, particularly in valuable parks and reserves, is not supported by these results.

Historical high-severity fire patches in mixed-conifer forests

2015 ◽  
Vol 45 (11) ◽  
pp. 1587-1596 ◽  
Author(s):  
Larissa L. Yocom-Kent ◽  
Peter Z. Fulé ◽  
Windy A. Bunn ◽  
Eric G. Gdula
Keyword(s):  
Fire Regime ◽  
Fire Severity ◽  
Grand Canyon ◽  
Fire Regimes ◽  
Tree Age ◽  
Mixed Conifer ◽  
Fire Scar ◽  
High Severity ◽  
The North ◽  
Mixed Conifer Forests

Two ends of the fire regime spectrum are a frequent low-intensity fire regime and an infrequent high-intensity fire regime, but intermediate fire regimes combine high- and low-severity fire over space and time. We used fire-scar and tree-age data to reconstruct fire regime attributes of mixed-conifer and aspen forests in the North Rim area of Grand Canyon National Park, with a goal of estimating patch sizes of historical high-severity fire and comparing them with modern patch sizes. We used three methods based on (i) aspen groves, (ii) even-aged stands, and (iii) inverse distance weighting, to estimate occurrence and patch sizes of historical high-severity fire. Evidence of high-severity fire was common in the 1800s, and high-severity fire years were associated with drought. High-severity fire patch sizes likely ranged from 10−1 to 102 ha. However, the forest is quite young, and we cannot rule out a historical large high-severity fire that could have reinitiated much of the 1400 ha study area. Fire scars, which are indicative of low-severity fire, were also common. Historical fire was likely heterogeneous across the landscape. Maintaining heterogeneity of fire severity, size, and frequency would promote heterogeneity of forest structure and composition and resilience to future disturbances.

Influence of short-interval fire occurrence on post-fire recovery of fire-prone shrublands in California, USA

2013 ◽  
Vol 22 (2) ◽  
pp. 184 ◽  
Author(s):  
Caitlin L. Lippitt ◽  
Douglas A. Stow ◽  
John F. O'Leary ◽  
Janet Franklin
Keyword(s):  
Life Histories ◽  
Fire History ◽  
Short Interval ◽  
Fire Regimes ◽  
Fire Frequency ◽  
Natural Occurrence ◽  
Contributing Factors ◽  
Type Conversion ◽  
Short Intervals ◽  
Mean Fire Interval

In recent decades, fire frequency has increased with population growth at the wildland–urban interface in southern California, USA. Short intervals (<5 years) between successive fires can be detrimental to plant species that require longer intervals between fires to reach reproductive maturity. The resilience of vegetation to changes in fire regimes is of particular interest for shrublands in Mediterranean climates, which in general are susceptible to high frequencies of wildfire. Research on how fire has shaped the life histories of shrubs in Mediterranean climates is central to understanding how to protect sensitive habitat while allowing for the natural occurrence of wildfire in these regions. Frequently burned chamise chaparral shrublands in San Diego County, California, were mapped in the field with the aid of satellite imagery and analysed to investigate changes in vegetation condition and composition associated with short intervals between fires. Fire history, terrain and land-cover characteristics of mapped stands were tested to determine the factors associated with disturbed and converted vegetation. Results indicate that number of burns and mean fire interval are contributing factors in post-fire change in chaparral stands. Chamise chaparral is vulnerable to alteration and type conversion when fire return intervals are 4–5 years or less.

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.

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