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

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.

2016 ◽  
Vol 38 (4) ◽  
pp. 391 ◽  
Author(s):  
J. L. Silcock ◽  
G. B. Witt ◽  
R. J. Fensham

Changes to fire regimes associated with European colonisation are implicated in declines in biodiversity and productivity in rangelands globally. However, for many areas there is incomplete knowledge of historical fire regimes and purported changes can become accepted wisdom with little empirical evidence. In the Mulga Lands of south-western Queensland, the dominant narrative implicates reduced fire frequency as a cause of woody vegetation thickening. We present a fire history of the Mulga Lands since pastoral exploration in the 1840s based on a review of explorer and early pastoralist journals, newspaper articles, interviews with long-term landholders and collation of satellite imagery. Fires in mulga communities are infrequent and only occur after at least two years of above-average summer rainfall. The assumption of regular pre-pastoral fires is not supported by available evidence. Since pastoral settlement in the 1860s, fire events affecting >1000 km2 have occurred seven times (1891–1892, 1904, 1918, 1950–1951, 1956–1957, 1976–1979 and 2011–2013), with only the 1950s fires affecting a >10% of the total area of mulga-dominated vegetation. We argue that fire is limited by fuel loads, which are in turn limited by rainfall events occurring only a few times a century. Even in the absence of grazing and active fire suppression fire intervals would be extremely long, perhaps 30–50 years in relatively fire-prone communities and much longer throughout most of the region. Combined with quantitative studies of fire and tree and shrub population dynamics, detailed fire histories will allow for more informed and nuanced debates about the role of fire in rangelands subject to abrupt management upheavals.


2011 ◽  
Vol 20 (2) ◽  
pp. 248 ◽  
Author(s):  
Tuomo Wallenius ◽  
Markku Larjavaara ◽  
Juha Heikkinen ◽  
Olga Shibistova

To study the poorly known fire history of Larix-dominated forest in central Siberia, we collected samples from 200 trees in 46 systematically located study plots. Our study area stretches ~90 km from north to south along the River Nizhnyaya Tunguska in northern Irkustk district. Cross-dated tree-ring chronology for all samples combined extended from the year 1360 AD to the present and included 76 fire years and 88 separate fire events. Average fire cycle gradually lengthened from 52 years in the 18th century to 164 years in the 20th century. During the same time, the number of recorded fires decreased even more steeply, i.e. by more than 85%. Fires were more numerous but smaller in the past. Contrary to expectations, climate change in the 20th century has not resulted in increased forest fires in this region. Fire suppression may have contributed to the scarcity of fires since the 1950s. However, a significant decline in fires was evident earlier; therefore an additional explanation is required, a reduction in human-caused ignitions being likely in the light of historical accounts.


2020 ◽  
Vol 29 (8) ◽  
pp. 649 ◽  
Author(s):  
Mauro E. González ◽  
Ariel A. Muñoz ◽  
Álvaro González-Reyes ◽  
Duncan A. Christie ◽  
Jason Sibold

Historical fire regimes are critical for understanding the potential effects of changing climate and human land-use on forest landscapes. Fire is a major disturbance process affecting the Andean Araucaria forest landscape in north-west Patagonia. The main goals of this study were to reconstruct the fire history of the Andean Araucaria–Nothofagus forests and to evaluate the coupled influences of climate and humans on fire regimes. Reconstructions of past fires indicated that the Araucaria forest landscape has been shaped by widespread, stand-replacing fires favoured by regional interannual climate variability related to major tropical and extratropical climate drivers in the southern hemisphere. Summer precipitation and streamflow reconstructions tended to be below average during fire years. Fire events were significantly related to positive phases of the Southern Annular Mode and to warm and dry summers following El Niño events. Although Euro-Chilean settlement (1883–1960) resulted in widespread burning, cattle ranching by Pehuenche Native Americans during the 18th and 19th centuries also appears to have changed the fire regime. In the context of climate change, two recent widespread wildfires (2002 and 2015) affecting Araucaria forests appear to be novel and an early indication of a climate change driven shift in fire regimes in north-west Patagonia.


Author(s):  
Stephen Barrett ◽  
Stephen Arno

This study's goal is to document the fire history of the Lamar River drainage, southeast of Soda Butte Creek in the Absaroka Mountains of northeastern Yellowstone National Park (YNP). Elsewhere in YNP investigators have documented very long-interval fire regimes for lodgepole pine forests occurring on rhyolitic derived soils (Romme 1982, Romme and Despain 1989) and short-interval fire regimes for the Douglas-fir/grassland types (Houston 1973). No fire regime information was available for lodgepole pine forests on andesitic derived soils, such as in the Lamar drainage. This study will provide managers with a more complete understanding of YNP natural fire history, and the data will supplement the park's Geographic Information System (GIS) data base. Moreover, most of the study area was severely burned in 1988 and historical tree ring data soon will be lost to attrition of potential sample trees.


1983 ◽  
Vol 61 (9) ◽  
pp. 2459-2471 ◽  
Author(s):  
David R. Foster

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.


2014 ◽  
Vol 20 (1) ◽  
pp. 57 ◽  
Author(s):  
Barbara A Wilson ◽  
Janine Kuehs ◽  
Leonie E Valentine ◽  
Tracy Sonneman ◽  
Kristen M Wolfe

In Mediterranean ecosystems prescribed burning is commonly employed to reduce the risk or intensity of wildfires. As a consequence, a major challenge for conservation land managers is the development of fire regimes that reduce damaging wildfires and are optimal for biodiversity. The aim of this paper was to develop guidelines for ecological fire regimes using the Banksia woodland on the Gnangara Groundwater System in Western Australia as a case study. Development of the guidelines involved the determination of maximum and minimum fire intervals of key fire response species, analyses of fire history records and estimation of ideal age class distributions at the landscape level. Recommendations included a) adoption of a minimum fire interval of 8–16 years, b) implementation of a burning regime to redress the current skewed distribution (60%: 1–7 years since last fire), c) retention of long-unburnt habitats that are significant for species such as the critically endangered Calyptorhynchus latirostris (Carnaby’s black-cockatoo), and Tarsipes rostratus (honey possum), and d) protection for wetlands that can serve as fire ‘refugia’ for associated species, such as Isoodon obesulus fusciventer (southern brown bandicoot or quenda). The guidelines developed provide a model for the development of ecological burning regimes in other similar ecosystems. The implementation of ecological guidelines normally involves incorporation into fire management planning by fire agencies and often entails complex solutions to conflicting aims. The guidelines are thus valuable for ecologists and land managers, especially in light of an expected significant increase in global fire activity as a consequence of predicted climate change.


2021 ◽  
Author(s):  
Nikos Koutsias ◽  
Anastasia Karamitsou ◽  
Foula Nioti ◽  
Frank Coutelieris

<p>Plant biomes and climatic zones are characterized by a specific type of fire regime which can be determined from the history of fires in the area and it is a synergy mainly of the climatic conditions and the functional characteristics of the types of vegetation. They correspond also to specific phenology types, a feature that can be useful for various applications related to vegetation monitoring, especially when remote sensing methods are used. Both the assessment of fire regime from the reconstruction of fire history and the monitoring of post-fire evolution of the burned areas can be studied with satellite remote sensing based on satellite time series images. The free availability of (i) Landsat satellite imagery by US Geological Survey (USGS, (ii) Sentinel-2 satellite imagery by ESA and (iii) MODIS satellite imagery by NASA / USGS allow low-cost data acquisition and processing (eg 1984-present) which otherwise would require very high costs. The purpose of this work is to determine the fire regime as well as the patterns of post-fire evolution of burned areas in selected vegetation/climate zones for the entire planet by studying the phenology of the landscape with time series of satellite images. More specifically, the three research questions we are negotiating are: (i) the reconstruction of the history of fires in the period 1984-2017 and the determination of fire regimes with Landsat and Sentinel-2 satellite data , (ii) the assessment of pre-fire phenological pattern of vegetation and (iii) the monitoring and comparative evaluation of post-fire evolution patterns of the burned areas.</p><p><strong>Acknowledgements</strong></p><p>This research has been co-financed by the Operational Program "Human Resources Development, Education and Lifelong Learning" and is co-financed by the European Union (European Social Fund) and Greek national funds.</p><p> </p>


2006 ◽  
Vol 15 (4) ◽  
pp. 489 ◽  
Author(s):  
Xiaojun Kou ◽  
William L. Baker

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.


2017 ◽  
Vol 26 (2) ◽  
pp. 136 ◽  
Author(s):  
Gregory A. Greene ◽  
Lori D. Daniels

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.


2013 ◽  
Vol 22 (2) ◽  
pp. 184 ◽  
Author(s):  
Caitlin L. Lippitt ◽  
Douglas A. Stow ◽  
John F. O'Leary ◽  
Janet Franklin

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.


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