Global fire size distribution is driven by human impact and climate

2014 ◽  
Vol 24 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Stijn Hantson ◽  
Salvador Pueyo ◽  
Emilio Chuvieco
Keyword(s):  
Size Distribution ◽  
Human Impact ◽  
Fire Size ◽  
Fire Size Distribution

scholarly journals Correction: Land cover, more than monthly fire weather, drives fire-size distribution in Southern Québec forests: Implications for fire risk management

PLoS ONE ◽  
2017 ◽  
Vol 12 (9) ◽  
pp. e0185515 ◽  
Author(s):  
Jean Marchal ◽  
Steve G. Cumming ◽  
Eliot J. B. McIntire
Keyword(s):  
Risk Management ◽  
Land Cover ◽  
Size Distribution ◽  
Fire Risk ◽  
Fire Weather ◽  
Fire Size ◽  
Fire Size Distribution

scholarly journals Land cover, more than monthly fire weather, drives fire-size distribution in Southern Québec forests: Implications for fire risk management

PLoS ONE ◽  
2017 ◽  
Vol 12 (6) ◽  
pp. e0179294 ◽  
Author(s):  
Jean Marchal ◽  
Steve G. Cumming ◽  
Eliot J. B. McIntire
Keyword(s):  
Risk Management ◽  
Land Cover ◽  
Size Distribution ◽  
Fire Risk ◽  
Fire Weather ◽  
Fire Size ◽  
Fire Size Distribution

A parametric model of the fire-size distribution

2001 ◽  
Vol 31 (8) ◽  
pp. 1297-1303 ◽  
Author(s):  
S G Cumming
Keyword(s):  
Size Distribution ◽  
Sampling Interval ◽  
Parametric Modelling ◽  
Fire Size ◽  
Disturbance History ◽  
Threshold Size ◽  
Mixedwood Forests ◽  
Large Fires ◽  
Fire Size Distribution ◽  
Burnt Areas

This paper developes statistical models of the size distribution of lightning-caused wildfires in the boreal mixedwood forests of Alberta, Canada, for the intervals 1980––1998 and 1961––1998. Above any minimum threshold size [Formula: see text]3 ha, the logarithm of fire size is approximately exponentially distributed. However, computer simulations using the best-fit distribution would over predict the frequency of large fires, and thus the mean rate of disturbance. A truncated exponential distribution, which places an upper bound on fire size, is more suitable and, according to probability plots, provides an excellent fit to the data. I estimate the maximum fire size in the study area to be [Formula: see text] 650 000 ha. This estimate is insensitive to the choice of lower bound for fire sizes (between 3 and 1000 ha) and to the choice of sampling interval. Parametric modelling of fire sizes using covariates derived from forest inventory data shows that the expected size of a fire is positively related to the abundance of pine forest in the vicinity of the point of detection and negatively related to the abundance of recently logged or burnt areas. This implies that variation in forest structure and disturbance history impose marked spatial variability on the fire size distribution. Other covariates, such as periodic indices of fire weather, could readily be evaluated in this framework.

Global fire size distribution: from power law to log-normal

2016 ◽  
Vol 25 (4) ◽  
pp. 403 ◽  
Author(s):  
Stijn Hantson ◽  
Salvador Pueyo ◽  
Emilio Chuvieco
Keyword(s):  
Size Distribution ◽  
Frequency Distribution ◽  
Power Law ◽  
Likelihood Estimation ◽  
Fire Size ◽  
Chi Square ◽  
Size Frequency Distribution ◽  
Size Frequency ◽  
Fire Size Distribution ◽  
Log Normal

Wildland fires are one of the main alleged examples of Self-Organised Criticality (SOC), with simple SOC models resulting in the expectation of a power-law fire size frequency distribution. Here, we test whether fire size distributions systematically follow a power law and analyse their spatial variation for eight distinct areas over the globe. For each of the areas, we examine the fire size frequency distribution using two types of plots, maximum likelihood estimation and chi-square tests. Log-normal emerges as a suitable option to fit the fire size distribution in this variety of environments. In only two of eight areas was the power law (which is a particular case of the log-normal) not rejected. Notably, the two parameters of log-normal are related to each other, displaying a general linear relation, which extends to the sites that can be described with a power law. These results do not necessarily refute the SOC hypothesis, but reveal the presence of other processes that are, at least, modulating the outcome of SOC in some areas.

What do we know about forest fire size distribution, and why is this knowledge useful for forest management?

2008 ◽  
Vol 17 (2) ◽  
pp. 234 ◽  
Author(s):  
Wenbin Cui ◽  
Ajith H. Perera
Keyword(s):  
Forest Management ◽  
Size Distribution ◽  
Forest Fire ◽  
Management Practices ◽  
Fire Management ◽  
Future Research ◽  
Research Approach ◽  
Fire Size ◽  
Forest Fire Management ◽  
Fire Size Distribution

Forest fire size distribution (FSD) is one of the suite of indicators of forest fire regimes. It is applied in forest fire management, particularly for planning and evaluating suppression efforts. It is also used in forest management in the context of emulating natural fire disturbances. Given the recent growth in research and applied interest in this topic, we review and synthesise the state of knowledge on FSD, and identify sources of knowledge uncertainties and future research directions. Based on literature, it is common for forest fires to follow the power law probability distribution, particularly the truncated subtype, under a variety of forest types and forest and fire management practices. Other types of FSD are also observed, but under specific circumstances. Although there is evidence that observed FSDs vary both over space and time, the knowledge is too fragmented to generalise the cause–effect relationships for such variation. As well, it is not clear how the various methods of studying FSD and their spatio-temporal scales influence derivations of FSDs. We suggest that a hypothetico-deductive research approach, combining empirical studies with process-based simulations is an effective means to advance the knowledge of FSD. We suggest caution in the use of FSD in forest management because applying different distributions or even different parameters for the same distribution may result in great fire size class differences and thus different implications for forest management.

Using spatially explicit simulations to explore size distribution and spacing of regenerating areas produced by wildfires: recommendations for designing harvest agglomerations for the Canadian boreal forest

2007 ◽  
Vol 83 (1) ◽  
pp. 72-83 ◽  
Author(s):  
Annie Belleau ◽  
Yves Bergeron ◽  
Alain Leduc ◽  
Sylvie Gauthier ◽  
Andrew Fall
Keyword(s):  
Forest Management ◽  
Boreal Forest ◽  
Size Distribution ◽  
Temporal Variability ◽  
Fire Regime ◽  
Natural Disturbance ◽  
Fire Regimes ◽  
Spatially Explicit ◽  
Fire Size ◽  
Canadian Boreal Forest

It is now recognized that in the Canadian boreal forest, timber harvesting activities have replaced wildfires as the main stand-replacing disturbance. Differences in landscape patterns derived from these two sources of disturbance have, however, raised concerns that the way forest harvesting has been dispersed is potentially shifting patterns away from the natural range. In the context of natural disturbance-based management, we used a spatially explicit model designed to capture general fire regimes in order to quantify temporal variability associated with regenerating areas (burnt areas of 25 years or younger), and to develop strategic objectives for harvest agglomeration sizes and dispersion. We first evaluated temporal variability in the proportion of stands younger than 100 years (assumed to be even-aged stands) for various fire regimes (seven fire cycles: 50 to 400 years, and three mean fires sizes: 3000, 15 000 and 60 000 ha). Secondly, we quantified the size distribution and dispersion of regenerating areas for each fire regime. As expected by theoretical fire frequencies and size distributions, the importance of even-aged stands at the forest management unit level was found to decrease with longer fire cycles. However, the temporal variability associated with these proportions is shown to increase with mean fire size. It was also observed that the size distribution and dispersion of regenerating areas was primarily influenced by mean fire size. Based on these observations, natural disturbance-based management objectives were formulated, providing guidelines on harvest agglomeration size and dispersion. Key words: temporal variability, boreal forest, fire regime, forest management, age distribution, fire size distribution, clearcut agglomeration size distribution

Fire regime from 1973 to 2011 in north-western Patagonian grasslands

2016 ◽  
Vol 25 (9) ◽  
pp. 922 ◽  
Author(s):  
Facundo José Oddi ◽  
Luciana Ghermandi
Keyword(s):  
Fire Regime ◽  
Terrestrial Ecosystems ◽  
Fire Regimes ◽  
Burned Area ◽  
General Knowledge ◽  
Fire Size ◽  
Socioeconomic Impacts ◽  
Mean Size ◽  
Fire Size Distribution ◽  
North Western

Fire is one of the most important disturbances in terrestrial ecosystems and has major ecological and socioeconomic impacts. Fire regime describes the variation of individual fire events in time and space. Few studies have characterised the fire regime in grasslands in spite of the importance of these ecosystems. The aim of this study was to describe the recent fire regime (from 1973 to 2011) of north-western Patagonian grasslands in terms of seasonality, frequency and burned area. Our study area covered 560 000 ha and we used a remote sensing approach combined with statistics obtained from operational databases. Fires occur during the summer in 2 of every 3 years with a frequency of 2.7 fires per year and a mean size of 823 ha. Fire size distribution is characterised by many small fires and few large ones which would respond to a distribution from the power law family. Eighty per cent of the total area affected by fire was burned in the span of a few years, which were also widespread fire years in forests and woodlands of north-western Patagonia. This work contributes to general knowledge about fire regimes in grasslands and we expect that our results will serve as a reference to further fire regime research.

scholarly journals Relationships between annual plant productivity, nitrogen deposition and fire size in low-elevation California desert scrub

2015 ◽  
Vol 24 (1) ◽  
pp. 48 ◽  
Author(s):  
Leela E. Rao ◽  
John R. Matchett ◽  
Matthew L. Brooks ◽  
Robert F. Johnson ◽  
Richard A. Minnich ◽  
...  
Keyword(s):  
Predictive Ability ◽  
Fire Risk ◽  
N Deposition ◽  
Fuel Load ◽  
Fire Size ◽  
Fuel Production ◽  
Desert Ecosystems ◽  
Fire Size Distribution ◽  
Fire Spreading ◽  
Desert Scrub

Although precipitation is correlated with fire size in desert ecosystems and is typically used as an indirect surrogate for fine fuel load, a direct link between fine fuel biomass and fire size has not been established. In addition, nitrogen (N) deposition can affect fire risk through its fertilisation effect on fine fuel production. In this study, we examine the relationships between fire size and precipitation, N deposition and biomass with emphasis on identifying biomass and N deposition thresholds associated with fire spreading across the landscape. We used a 28-year fire record of 582 burns from low-elevation desert scrub to evaluate the relationship of precipitation, N deposition and biomass with the distribution of fire sizes using quantile regression. We found that models using annual biomass have similar predictive ability to those using precipitation and N deposition at the lower to intermediate portions of the fire size distribution. No distinct biomass threshold was found, although within the 99th percentile of the distribution fire size increased with greater than 125 g m–2 of winter fine fuel production. The study did not produce an N deposition threshold, but did validate the value of 125 g m–2 of fine fuel for spread of fires.

The extinction time of a general birth and death process with catastrophes

1986 ◽  
Vol 23 (04) ◽  
pp. 851-858 ◽  
Author(s):  
P. J. Brockwell
Keyword(s):  
Laplace Transform ◽  
Size Distribution ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Death Process ◽  
Extinction Time ◽  
Birth And Death Process ◽  
Different Types ◽  
The Laplace Transform ◽  
Necessary And Sufficient

The Laplace transform of the extinction time is determined for a general birth and death process with arbitrary catastrophe rate and catastrophe size distribution. It is assumed only that the birth rates satisfyλ0= 0,λj> 0 for eachj> 0, and. Necessary and sufficient conditions for certain extinction of the population are derived. The results are applied to the linear birth and death process (λj=jλ, µj=jμ) with catastrophes of several different types.

Macrostructure and microphysics of Saturn's E-ring

1984 ◽  
Vol 75 ◽  
pp. 607-613 ◽  
Author(s):  
Kevin D. Pang ◽  
Charles C. Voge ◽  
Jack W. Rhoads
Keyword(s):  
Size Distribution ◽  
Spherical Shape ◽  
Mie Scattering ◽  
Narrow Size Distribution ◽  
Electrostatic Levitation ◽  
Volcanic Origin ◽  
Micron Diameter

Abstract.All observed optical and infrared properties of Saturn's E-ring can be explained in terms of Mie scattering by a narrow size distribution of ice spheres of 2 - 2.5 micron diameter. The spherical shape of the ring particles and their narrow size distribution imply a molten (possibly volcanic) origin on Enceladus. The E-ring consists of many layers, possibly stratified by electrostatic levitation.

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