scholarly journals Exploring spatial–temporal dynamics of fire regime features in mainland Spain

2017 ◽  
Vol 17 (10) ◽  
pp. 1697-1711 ◽  
Author(s):  
Adrián Jiménez-Ruano ◽  
Marcos Rodrigues Mimbrero ◽  
Juan de la Riva Fernández
Keyword(s):  
Temporal Dynamics ◽  
Fire Regime ◽  
Fire Frequency ◽  
Change Point Detection ◽  
Burnt Area ◽  
Temporal Behaviour ◽  
Sen’S Slope ◽  
Large Fires ◽  
The Mediterranean ◽  
In Fire

Abstract. This paper explores spatial–temporal dynamics in fire regime features, such as fire frequency, burnt area, large fires and natural- and human-caused fires, as an essential part of fire regime characterization. Changes in fire features are analysed at different spatial – regional and provincial/NUTS3 – levels, together with summer and winter temporal scales, using historical fire data from Spain for the period 1974–2013. Temporal shifts in fire features are investigated by means of change point detection procedures – Pettitt test, AMOC (at most one change), PELT (pruned exact linear time) and BinSeg (binary segmentation) – at a regional level to identify changes in the time series of the features. A trend analysis was conducted using the Mann–Kendall and Sen's slope tests at both the regional and NUTS3 level. Finally, we applied a principal component analysis (PCA) and varimax rotation to trend outputs – mainly Sen's slope values – to summarize overall temporal behaviour and to explore potential links in the evolution of fire features. Our results suggest that most fire features show remarkable shifts between the late 1980s and the first half of the 1990s. Mann–Kendall outputs revealed negative trends in the Mediterranean region. Results from Sen's slope suggest high spatial and intra-annual variability across the study area. Fire activity related to human sources seems to be experiencing an overall decrease in the northwestern provinces, particularly pronounced during summer. Similarly, the Hinterland and the Mediterranean coast are gradually becoming less fire affected. Finally, PCA enabled trends to be synthesized into four main components: winter fire frequency (PC1), summer burnt area (PC2), large fires (PC3) and natural fires (PC4).

scholarly journals Exploring spatial-temporal dynamics of fire regime features at mainland Spain

2017 ◽  
Author(s):  
Adrián Jiménez-Ruano ◽  
Marcos Rodrigues Mimbrero ◽  
Juan de la Riva Fernández
Keyword(s):  
Temporal Dynamics ◽  
Fire Regime ◽  
Fire Frequency ◽  
Change Point Detection ◽  
Burnt Area ◽  
Temporal Behaviour ◽  
Sen’S Slope ◽  
Large Fires ◽  
The Mediterranean ◽  
In Fire

Abstract. This paper explores spatial-temporal dynamics in fire regime features, such as fire frequency, burnt area, large fires, and natural- and human-caused fires, as an essential part of fire regime characterisation. Changes in fire features are analysed at different spatial–regional and provincial/NUTS3 levels, together with summer and winter temporal scales, using historical fire data from Spain for the period 1974–2013. Temporal shifts in fire features are investigated by means of change point detection procedures – Pettitt test, AMOC (At Most One Change), PELT (Pruned Exact Linear Time) and BinSeg (Binary Segmentation) – at regional level to identify changes in the time series of the features. A trend analysis was conducted using the Mann–Kendall and Sen's slope tests at both regional and NUTS3 level. Finally, we applied a Principal Component Analysis (PCA) and Varimax Rotation to trend outputs – mainly Sen's slope values – to summarize overall temporal behaviour, also to explore potential links in the evolution of fire features. Our results suggest that most fire features show remarkable shifts between the late 1980s and the first half of the 1990s. Mann–Kendall outputs revealed negative trends in the Mediterranean region. Results from Sen's slope suggest high spatial and intra-annual variability across the study area. Fire activity related to human sources seems to be experiencing an overall decrease in the north-west provinces, particularly pronounced during summer. Conversely, the hinterlands and the Mediterranean coast are gradually becoming less fire-affected. Finally, PCA enabled trends to be synthesized into four main components: winter fire frequency (PC1), summer burnt area (PC2), large fires (PC3) and natural fires (PC4).

Fire history in relation to site type and vegetation in Vienansalo wilderness in eastern Fennoscandia, Russia

2004 ◽  
Vol 34 (7) ◽  
pp. 1400-1409 ◽  
Author(s):  
Tuomo H Wallenius ◽  
Timo Kuuluvainen ◽  
Ilkka Vanha-Majamaa
Keyword(s):  
Fire History ◽  
Fire Regime ◽  
Forest Type ◽  
Fire Frequency ◽  
Small Scale ◽  
Forest Patches ◽  
Burnt Area ◽  
Wilderness Area ◽  
In Fire ◽  
Scale Variation

A wildfire area in a boreal forest landscape dominated by Pinus sylvestris L., in the Vienansalo wilderness area in eastern Fennoscandia, was examined for its spatial characteristics and fire history. The boundaries of the 360-ha fire that occurred in 1969 were mapped, and the vegetation types of burnt and unburnt areas were inventoried. Fire history was investigated in 40 study plots, and fire scars, tree ages, and charcoal in peat or soil were used for evidence of past fires. The complex shape of the 1969 fire and the detected small-scale variation in past fire frequencies were concordant with the existing small-scale variation in site moisture and vegetation characteristics in the area. Moist depressions, swamps, and more fertile forest patches dominated by Picea abies (L.) Karst. often did not burn when the nearby dryish forest type did. There was also temporal variability in fire frequency. An abrupt increase in the number of fires occurred in the late 17th century. In the mid-19th century, both the number of fires and the annually burnt area in the region decreased. Our results show that in the examined wildfire area, there has been considerable and consistent small-scale spatial variation in fire frequency and that historical fire regime evidently has been strongly affected by human activity.

Fire regime shift linked to increased forest density in a piñon–juniper savanna landscape

2014 ◽  
Vol 23 (2) ◽  
pp. 234 ◽  
Author(s):  
Ellis Q. Margolis
Keyword(s):  
Regime Shift ◽  
Fire History ◽  
Fire Regime ◽  
Fire Regimes ◽  
Fire Frequency ◽  
Climatic Conditions ◽  
Tree Density ◽  
High Severity ◽  
Wide Range ◽  
In Fire

Piñon–juniper (PJ) fire regimes are generally characterised as infrequent high-severity. However, PJ ecosystems vary across a large geographic and bio-climatic range and little is known about one of the principal PJ functional types, PJ savannas. It is logical that (1) grass in PJ savannas could support frequent, low-severity fire and (2) exclusion of frequent fire could explain increased tree density in PJ savannas. To assess these hypotheses I used dendroecological methods to reconstruct fire history and forest structure in a PJ-dominated savanna. Evidence of high-severity fire was not observed. From 112 fire-scarred trees I reconstructed 87 fire years (1547–1899). Mean fire interval was 7.8 years for fires recorded at ≥2 sites. Tree establishment was negatively correlated with fire frequency (r=–0.74) and peak PJ establishment was synchronous with dry (unfavourable) conditions and a regime shift (decline) in fire frequency in the late 1800s. The collapse of the grass-fuelled, frequent, surface fire regime in this PJ savanna was likely the primary driver of current high tree density (mean=881treesha–1) that is >600% of the historical estimate. Variability in bio-climatic conditions likely drive variability in fire regimes across the wide range of PJ ecosystems.

scholarly journals The history and characteristics of the 1980–2005 Portuguese rural fire database

2011 ◽  
Vol 11 (12) ◽  
pp. 3343-3358 ◽  
Author(s):  
M. G. Pereira ◽  
B. D. Malamud ◽  
R. M. Trigo ◽  
P. I. Alves
Keyword(s):  
Urban Areas ◽  
Unit Area ◽  
Fire Regime ◽  
Minimum Area ◽  
Burnt Area ◽  
Forested Areas ◽  
Large Fires ◽  
Burnt Areas

Abstract. We focus here on a mainland Continental Portuguese Rural Fire Database (PRFD) that includes 450 000 fires, the largest such database in Europe in terms of total number of recorded fires in the 1980–2005 period. In this work, we (a) list the most important factors for triggering and controlling the fire regime in mainland Continental Portugal, (b) describe the dataset's production, (c) discuss procedures adopted to identify and correct different fire data inconsistencies, creating a modified PRFD which we use here and make available as Supplement, (d) explore some basic temporal and completeness properties of the data. We find that the dataset's minimum measured burnt areas have changed with time between AF = 0.1 ha (1980–1990), AF = 0.01 ha (1991–1992), and AF = 0.001 ha (1992–2005), with varying degrees of completeness down to these values. These changes in minimum area measured are responsible for greater numbers of fires being recorded. A relatively small number of large fires in the PRFD are responsible for the majority of the burnt area. For example, fires with AF > 100 ha represent about 1% of all fire records but 75% of total burnt area. Finally, we consider for each Continental Portugal district and for the 26-yr period, the total number of rural fires and area burnt in forests and shrublands, each normalized by district areas. We find that the highest numbers of fires per unit area are in highly populated districts, and that the largest fraction of burnt area is in forested areas, coinciding with large parcels of continuous forests (predominantly rural and moderately urban areas).

Mapping fire regime ecoregions in California

2020 ◽  
Vol 29 (7) ◽  
pp. 595 ◽  
Author(s):  
Alexandra D. Syphard ◽  
Jon E. Keeley
Keyword(s):  
Fire Regime ◽  
Fire Severity ◽  
Fire Regimes ◽  
Unsupervised Classification ◽  
Fire Frequency ◽  
The State ◽  
Reduction Strategies ◽  
Lower Variability ◽  
Fire Characteristics ◽  
In Fire

The fire regime is a central framing concept in wildfire science and ecology and describes how a range of wildfire characteristics vary geographically over time. Understanding and mapping fire regimes is important for guiding appropriate management and risk reduction strategies and for informing research on drivers of global change and altered fire patterns. Most efforts to spatially delineate fire regimes have been conducted by identifying natural groupings of fire parameters based on available historical fire data. This can result in classes with similar fire characteristics but wide differences in ecosystem types. We took a different approach and defined fire regime ecoregions for California to better align with ecosystem types, without using fire as part of the definition. We used an unsupervised classification algorithm to segregate the state into spatial clusters based on distinctive biophysical and anthropogenic attributes that drive fire regimes – and then used historical fire data to evaluate the ecoregions. The fire regime ecoregion map corresponded well with the major land cover types of the state and provided clear separation of historical patterns in fire frequency and size, with lower variability in fire severity. This methodology could be used for mapping fire regimes in other regions with limited historical fire data or forecasting future fire regimes based on expected changes in biophysical characteristics.

scholarly journals Estimating carbon emissions from African wildfires

2009 ◽  
Vol 6 (3) ◽  
pp. 349-360 ◽  
Author(s):  
V. Lehsten ◽  
K. Tansey ◽  
H. Balzter ◽  
K. Thonicke ◽  
A. Spessa ◽  
...  
Keyword(s):  
Carbon Emissions ◽  
Net Primary Productivity ◽  
Fire Regime ◽  
Climatic Conditions ◽  
Burned Area ◽  
Similar Response ◽  
Response Patterns ◽  
Model Framework ◽  
Burnt Area ◽  
In Fire

Abstract. We developed a technique for studying seasonal and interannual variation in pyrogenic carbon emissions from Africa using a modelling approach that scales burned area estimates from L3JRC, a map recently generated from remote sensing of burn scars instead of active fires. Carbon fluxes were calculated by the novel fire model SPITFIRE embedded within the dynamic vegetation model framework LPJ-GUESS, using daily climate input. For the time period from 2001 to 2005 an average area of 195.5±24×104 km2 was burned annually, releasing an average of 723±70 Tg C to the atmosphere; these estimates for the biomass burned are within the range of previously published estimates. Despite the fact that the majority of wildfires are ignited by humans, strong relationships between climatic conditions (particularly precipitation), net primary productivity and overall biomass burnt emerged. Our investigation of the relationships between burnt area and carbon emissions and their potential drivers available litter and precipitation revealed uni-modal responses to annual precipitation, with a maximum around 1000 mm for burned area and emissions, or 1200 mm for litter availability. Similar response patterns identified in savannahs worldwide point to precipitation as a chief determinant for short-term variation in fire regime. A considerable variability that cannot be explained by fire-precipitation relationships alone indicates the existence of additional factors that must be taken into account.

scholarly journals Small mammals decline with increasing fire extent in northern Australia: evidence from long-term monitoring in Kakadu National Park

2015 ◽  
Vol 24 (5) ◽  
pp. 712 ◽  
Author(s):  
Michael J. Lawes ◽  
Brett P. Murphy ◽  
Alaric Fisher ◽  
John C. Z. Woinarski ◽  
Andrew C. Edwards ◽  
...  
Keyword(s):  
Small Mammals ◽  
National Park ◽  
Fire Regime ◽  
Fire Regimes ◽  
Fire Frequency ◽  
Small Scale ◽  
Northern Australia ◽  
Fire Size ◽  
Burnt Area ◽  
Fire Extent

Small mammal (<2 kg) numbers have declined dramatically in northern Australia in recent decades. Fire regimes, characterised by frequent, extensive, late-season wildfires, are implicated in this decline. Here, we compare the effect of fire extent, in conjunction with fire frequency, season and spatial heterogeneity (patchiness) of the burnt area, on mammal declines in Kakadu National Park over a recent decadal period. Fire extent – an index incorporating fire size and fire frequency – was the best predictor of mammal declines, and was superior to the proportion of the surrounding area burnt and fire patchiness. Point-based fire frequency, a commonly used index for characterising fire effects, was a weak predictor of declines. Small-scale burns affected small mammals least of all. Crucially, the most important aspects of fire regimes that are associated with declines are spatial ones; extensive fires (at scales larger than the home ranges of small mammals) are the most detrimental, indicating that small mammals may not easily escape the effects of large and less patchy fires. Notwithstanding considerable management effort, the current fire regime in this large conservation reserve is detrimental to the native mammal fauna, and more targeted management is required to reduce fire size.

scholarly journals Current and future estimates for the fire frequency and the fire rotation period in the main woodland types of peninsular Spain: a case-study approach

2015 ◽  
Vol 24 (2) ◽  
pp. e031 ◽  
Author(s):  
Antonio Vázquez ◽  
José M. Climent ◽  
Luis Casais ◽  
José R. Quintana
Keyword(s):  
Forest Fires ◽  
Fire Regime ◽  
Rotation Period ◽  
Fire Frequency ◽  
Large Variability ◽  
Rotation Periods ◽  
In Fire ◽  
Climatic Scenario ◽  
Peninsular Spain ◽  
Reference Areas

<p><em>Aim of study</em>. Fire regimes are frequently dynamic and change as a function of the interactions between the three main fire drivers: fuels, ignitions and climatic conditions. We characterized the recent period (1974-2005) and performed estimates for the future fire regime</p><p><em>Area of study</em>. We have considered five pine and another four woodland types by means of the analyses of 100 reference areas in peninsular Spain.</p><p><em>Material and methods</em>. The estimates of the expected alterations in fire frequency and the fire rotation period were based on models previously developed for the climatic scenarios SRES A2 and B2.</p><p><em>Main results</em>. The results point to the large variability in fire frequency and rotation periods between the woodland types as defined, and also among the reference areas delimited for each of them. Fire frequencies will increase for all woodland types while very relevant shortenings of the fire rotation periods are expected. For the 32 yr period analysed, rotation periods longer than 500 yr were obtained in 54% of the reference areas while this percentage would decrease to 31% in the B2 and to 29% in the A2 climatic scenario. In the most affected woodland type, <em>P. pinaster</em>, from a median rotation period of 83 yr it would decrease to 26 yr in the B2 and to 20 yr in the A2 climatic scenario.</p><p><em>Research highlights</em>. We conclude that the predicted increases in fire activity will have adverse effects on some of the main Spanish woodland types due to the expected future disruptions in the fire regime.  </p><p><strong>Keywords: </strong>Forest fires; fire regime; fire frequency; fire rotation period; climatic change.</p><p><strong>Abbreviations used: </strong>SRES: Special Report on Emissions Scenarios; IPCC: Intergovernmental Panel on Climate Change; RA: Reference Areas.</p>

scholarly journals Postglacial Fire Frequency and its Relation to Long-Term Vegetational and Climatic Changes in Yellowstone Park

1992 ◽  
Vol 16 ◽  
pp. 212-218
Author(s):  
Cathy Whitlock
Keyword(s):  
Fire Regime ◽  
Fire Frequency ◽  
Northern Rocky Mountains ◽  
Modern Pollen ◽  
Pollen Rain ◽  
History Of ◽  
Fossil Records ◽  
In Fire ◽  
The Relationship

The primary research objective has been to study the vegetational history of Yellowstone and its sensitivity to changes in climate and fire frequency. To establish a sequence of vegetational changes, a network of pollen records spanning the last 14,000 years has been studied from different types of vegetation within the Park. The relationship between modern pollen rain, modern vegetation and present­day climate in the northern Rocky Mountains has been the basis for interpreting past vegetation and climate from the fossil records. Changes in fire regime during the past 14,000 years have been inferred from sedimentary charcoal and other fire proxy in lake sediments. Calibration of the fire signal is based on a study that measures the input of charcoal into lakes following the 1988 fires in Yellowstone.

scholarly journals An assessment of the implementation and outcomes of recent changes to fire management in the Kruger National Park

Koedoe ◽  
2008 ◽  
Vol 50 (1) ◽  
Author(s):  
Brian W. Van Wilgen ◽  
Navashni Govender ◽  
Sandra MacFadyen
Keyword(s):  
National Park ◽  
Fire Management ◽  
Fire Regime ◽  
Kruger National Park ◽  
Fire Intensity ◽  
Target Area ◽  
Large Fires ◽  
Sufficient Degree ◽  
Burnt Areas ◽  
In Fire

This paper reviews recent changes in fire management in the Kruger National Park, and assesses the resulting fire patterns against thresholds of potential concern. In 2002, a lightning-driven approach was replaced by an approach that combined point ignitions with unplanned and lightning fires. The approach aimed to burn an annual target area, determined by rainfall and fuel conditions, in point-ignition fires of different sizes. Most of the original fire-related thresholds of potential concern (TPCs) were incorporated into the new approach. The annual target area to be burnt ranged from 12 to 24% of the park between 2002 and 2006. The total area burnt generally exceeded the targets each year, and management fires accounted for less than half of the total area burnt. The fire regime was dominated by very large fires (> 5 000 ha) which accounted for 77% of the total area burnt. New TPCs were developed to assess whether the fire regime encompassed a sufficient degree of variability, in terms of fire intensity and the spatial distribution of burnt areas. After assessment and adjustment, it appears that these TPCs have not yet been exceeded. The point-ignition approach, and its evaluation in terms of variability and heterogeneity, is based on the untested assumption that a diverse fire regime will promote biodiversity. This assumption needs to be critically assessed. We recommend that the practice of point ignitions be continued, but that greater efforts be made to burn larger areas earlier in the season to reduce large and intense dry-season fires.

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