scholarly journals Nesting Effects of Climate and Local Drivers on Long-Term Subalpine Fires in the Alps

2021 ◽  
Author(s):  
Christopher Carcaillet ◽  
Benjamin Boulley ◽  
Frédérique Carcaillet
Keyword(s):  
Biomass Burning ◽  
Large Scale ◽  
Fire History ◽  
Fire Regime ◽  
Western Alps ◽  
Biomass Combustion ◽  
Human Society ◽  
The Holocene ◽  
Soil Charcoal

Abstract Background: The present article questions the relative importance of local- and large-scale processes on the long-term dynamics of fire in the subalpine belt in the western Alps. The study is based on soil charcoal dating and identification, several study sites in contrasting environmental conditions, and sampling of soil charcoal along the elevation gradient of each site. Based on local differences in biomass combustion, we hypothesize that local-scale processes have driven the fire history, while combustion homogeneity supports the hypothesis of the importance of large-scale processes, especially the climate. Results: The results show that biomass burning during the Holocene resulted from the nesting effects of climate, land use, and altitude, but was little influenced by topography (slope exposure: north versus south), soil (dryness, pH, depth), and vegetation. The mid-Holocene (6500–2700 cal BP) was an important period for climatic biomass burning in the subalpine ecosystems of the western Alps, while fires from about 2500 years ago appear much more episodic, prompting us to speculate that human society has played a vital role in their occurrence. Conclusion: Our working hypothesis assuming that the strength of mountain natural and local drivers should offset the effects of regional climate is not validated. The homogeneity of the fire regime between sites thus underscore that climate was the main driver during the Holocene of the western Alps. Long-term subalpine fires are controlled by climate at millennial scale. Local conditions count for little in determining variability at the century scale. The mid-Holocene was a chief period for climatic biomass burning in the subalpine zone, while fires during the late Holocene appear much more episodic, prompting the assumption that societal drivers has exercised key roles on their control.

Role of vegetation on fire behaviour in Fennoscandia forests during the Holocene

2020 ◽  
Author(s):  
Chiara Molinari ◽  
Richard H.W. Bradshaw ◽  
Christopher Carcaillet ◽  
Gina Hannon ◽  
Veiko Lehsten
Keyword(s):  
Biomass Burning ◽  
Large Scale ◽  
Fire Regime ◽  
Fire Disturbance ◽  
Forest Composition ◽  
Peat Bogs ◽  
Fuel Type ◽  
Strong Negative Correlation ◽  
The Holocene

<p>The relationship between Holocene changes in Fennoscandia biomass burning (reconstructed by means of sedimentary charcoal records from lake and peat bogs) and main forest composition (based on pollen reconstructions from the same sites) divided into three different fire sensitivity classes is explored based on the hypothesis that fire-prone species are more abundant during periods characterized by higher fire disturbance, while fire-intolerant species dominate when biomass burning is low.</p><p>The overall patterns found across Fennoscandia suggest that there was low but increasing fire activity during the early Holocene, while a low and decreasing trend characterized the middle Holocene. During the late Holocene biomass burning increased, with a peak around 500 cal yr BP. This maximum is then followed by a downturn during the last centuries.</p><p>Generally, fire-prone species are strongly positively correlated with multi-millennial variability of biomass burning in Fennoscandia forests. A positive - but much weaker - relationship also exists between fire-tolerant species and long-term fire trends. On the contrary, a quite strong negative correlation is detected between biomass burning and fire-intolerant species.</p><p>The results presented in this large-scale analysis demonstrate that biomass burning was highly linked to fuel type (according to different fire sensitivity classes) during the Holocene, underlying the fact that all past fire-climate studies must consider key functional interactions between fuel type and long-term changes in fire regime.</p>

11 000 years of fire history and climate in the mountain hemlock rain forests of southwestern British Columbia based on sedimentary charcoal

2003 ◽  
Vol 33 (2) ◽  
pp. 292-312 ◽  
Author(s):  
Douglas J Hallett ◽  
Dana S Lepofsky ◽  
Rolf W Mathewes ◽  
Ken P Lertzman
Keyword(s):  
British Columbia ◽  
Lake Sediment ◽  
Fire History ◽  
Fire Regime ◽  
Fire Frequency ◽  
Summer Drought ◽  
Rain Forests ◽  
Independent Evidence ◽  
The Holocene ◽  
Soil Charcoal

Little is known about the role of fire in the mountain hemlock (Tsuga mertensiana (Bong.) Carrière) rain forests of southern British Columbia. High-resolution analysis of macroscopic charcoal from lake sediment cores, along with 102 accelerator mass spectrometry (AMS) ages on soil charcoal, was used to reconstruct the long-term fire history around two subalpine lakes in the southern Coast and North Cascade Mountains. AMS ages on soil charcoal provide independent evidence of local fire around a lake and support the interpretation of peaks in lake sediment charcoal as distinct fire events during the Holocene. Local fires are rare, with intervals ranging from centuries to several millennia at some sites. Overall fire frequency varied continuously throughout the Holocene, suggesting that fire regimes are linked to climate via large-scale atmospheric circulation patterns. Fires were frequent between 11 000 and 8800 calendar years BP during the warm and dry early Holocene. The onset of humid conditions in the mid-Holocene, as rain forest taxa established in the region, produced a variable fire period until 3500 calendar years BP. A synchronous decrease in fire frequency from 3500 to 2400 calendar years BP corresponds to Neoglacial advances in the region and cool humid climate. A return of frequent fire between 2400 and 1300 calendar years BP suggests that prolonged summer drought occurred more often during this interval, which we name the Fraser Valley Fire Period. The present-day fire regime was established after 1300 calendar years BP.

Fire history on a desert mountain range: Rincon Mountain Wilderness, Arizona, U.S.A.

1990 ◽  
Vol 20 (10) ◽  
pp. 1559-1569 ◽  
Author(s):  
Christopher H. Baisan ◽  
Thomas W. Swetnam
Keyword(s):  
Tree Ring ◽  
Large Scale ◽  
Fire History ◽  
Fire Regime ◽  
Forest Type ◽  
Drought Severity ◽  
Mountain Range ◽  
Mixed Conifer ◽  
The Mean ◽  
Mean Fire Interval

Modern fire records and fire-scarred remnant material collected from logs, snags, and stumps were used to reconstruct and analyze fire history in the mixed-conifer and pine forest above 2300 m within the Rincon Mountain Wilderness of Saguaro National Monument, Arizona, United States. Cross-dating of the remnant material allowed dating of fire events to the calendar year. Estimates of seasonal occurrence were compiled for larger fires. It was determined that the fire regime was dominated by large scale (> 200 ha), early-season (May–July) surface fires. The mean fire interval over the Mica Mountain study area for the period 1657–1893 was 6.1 years with a range of 1–13 years for larger fires. The mean fire interval for the mixed-conifer forest type (1748–1886) was 9.9 years with a range of 3–19 years. Thirty-five major fire years between 1700 and 1900 were compared with a tree-ring reconstruction of the Palmer drought severity index (PDSI). Mean July PDSI for 2 years prior to fires was higher (wetter) than average, while mean fire year PDSI was near average. This 490-year record of fire occurrence demonstrates the value of high-resolution (annual and seasonal) tree-ring analyses for documenting and interpreting temporal and spatial patterns of past fire regimes.

Reconstruction of fire regime changes in the French Mediterranean region during the last 8,500 years using microcharcoal 

2021 ◽  
Author(s):  
Marion Genet ◽  
Anne-Laure Daniau ◽  
Maria-Angela Bassetti ◽  
Bassem Jallali ◽  
Marie-Alexandrine Sicre ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Mediterranean Region ◽  
Fire History ◽  
Fine Particles ◽  
Fire Regime ◽  
Hot Spot ◽  
Sediment Delivery ◽  
Climate Conditions ◽  
North West ◽  
Gulf Of Lion

<p>Nowadays, the Mediterranean region is strongly impacted by fires. Projected warming scenarios suggest increasing fire risk in this region considered as hot-spot of the climate change (Liu et al., 2010; Pechony and Shindell, 2010). However, models based on modern-day statistical relationships do not properly account for interactions between climate, vegetation, and fire. In addition, process-based models must be tested not only against modern observations but also under different past climate conditions reflecting the range of climate variability projected for the next centuries (Hantson et al. 2016). Marine sediments are a major source of fire history of nearby land masses. Here, we present a unique 8,500 yr long record of biomass burning changes from southeastern France based on a marine microcharcoal sedimentary record from the Gulf of Lion, located in the subaqueous Rhone river delta. Sediment delivery to the Gulf of Lion comes mainly from the Rhône River draining a large watershed in southeast France (ca.100,000 km2). Due to the direction of dominant winds blowing from the North-North-West (Mistral and Tramontane) and carrying fine particles from the land to the sea, the microcharcoal record likely reflects the biomass burning in the Rhone watershed and South-East of France. Our results show multi-centennial to millennial changes in biomass burning with a periodicity  of 1000 years for the full record and between 500 and 700 years before 5,000 cal BP and after 3,000 cal BP. Large peaks of biomass burning are associated with marked dry periods observed in the region. Burning of biomass is higher when the region is dominated by xerophytic vegetation than when mesophyte vegetation dominates. The trend and periodicity of the biomass burning record suggest a predominant climatic control of fire occurrences since 8,500 cal BP in this region.</p>

Long-term deforestation in NW Spain: linking the Holocene fire history to vegetation change and human activities

2011 ◽  
Vol 30 (1-2) ◽  
pp. 161-175 ◽  
Author(s):  
Joeri Kaal ◽  
Yolanda Carrión Marco ◽  
Eleni Asouti ◽  
Maria Martín Seijo ◽  
Antonio Martínez Cortizas ◽  
...  
Keyword(s):  
Human Activities ◽  
Vegetation Change ◽  
Fire History ◽  
Nw Spain ◽  
The Holocene

scholarly journals Effects of vegetation zones and climatic changes on fire-induced atmospheric carbon emissions: a model based on paleodata

2010 ◽  
Vol 19 (8) ◽  
pp. 1015 ◽  
Author(s):  
Laurent Bremond ◽  
Christopher Carcaillet ◽  
Charly Favier ◽  
Adam A. Ali ◽  
Cédric Paitre ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Carbon Emissions ◽  
Fire History ◽  
Original Method ◽  
Total Carbon ◽  
Eastern Canada ◽  
Carbon Release ◽  
Boreal Shield ◽  
Global Carbon

An original method is proposed for estimating past carbon emissions from fires in order to understand long-term changes in the biomass burning that, together with vegetation cover, act on the global carbon cycle and climate. The past carbon release resulting from paleo-fires during the Holocene is examined using a simple linear model between measured carbon emissions from modern fires and sedimentary charcoal records of biomass burning within boreal and cold temperate forests in eastern Canada (Quebec, Ontario). Direct carbon emissions are estimated for each ecozone for the present period and the fire anomaly per kilo annum (ka) v. present day (0 ka) deduced from charcoal series of 46 lakes and peats. Over the postglacial, the Taiga Shield ecozone does not match the pattern of fire history and carbon release of Boreal Shield, Atlantic Maritime, and Mixedwood Plains ecozones. This feature results from different air mass influences and the timing of vegetation dynamics. Our estimations show, first, that the contribution of the Mixedwood Plains and the Atlantic Maritime ecozones on the total carbon emissions by fires remains negligible compared with the Boreal Shield. Second, the Taiga Shield plays a key role by maintaining important carbon emissions, given it is today a lower contributor.

scholarly journals Five thousand years of fire history in the high North Atlantic region: natural variability and ancient human forcing

2021 ◽  
Vol 17 (4) ◽  
pp. 1533-1545
Author(s):  
Delia Segato ◽  
Maria Del Carmen Villoslada Hidalgo ◽  
Ross Edwards ◽  
Elena Barbaro ◽  
Paul Vallelonga ◽  
...  
Keyword(s):  
Black Carbon ◽  
Biomass Burning ◽  
North Atlantic ◽  
Atmospheric Chemistry ◽  
Fire History ◽  
Fire Regime ◽  
Ice Core ◽  
North Atlantic Region ◽  
Atlantic Region ◽  
Ice Cap

Abstract. Biomass burning influences global atmospheric chemistry by releasing greenhouse gases and climate-forcing aerosols. There is controversy about the magnitude and timing of Holocene changes in biomass burning emissions from millennial to centennial timescales and, in particular, about the possible impact of ancient civilizations. Here we present a 5 kyr record of fire activity proxies levoglucosan, black carbon, and ammonium measured in the RECAP (Renland ice cap) ice core, drilled in coastal eastern Greenland, and therefore affected by processes occurring in the high North Atlantic region. Levoglucosan and ammonium fluxes are high from 5 to 4.5 kyr BP (thousand years before 2000 CE) followed by an abrupt decline, possibly due to monotonic decline in Northern Hemisphere summer insolation. Levoglucosan and black carbon show an abrupt decline at 1.1 kyr BP, suggesting a decline in the wildfire regime in Iceland due to the extensive land clearing caused by Viking colonizers. All fire proxies reach a minimum during the second half of the last century, after which levoglucosan and ammonium fluxes increase again, in particular over the last 200 years. We find that the fire regime reconstructed from RECAP fluxes seems mainly related to climatic changes; however over the last millennium human activities might have influenced wildfire frequency/occurrence substantially.

scholarly journals Assessing the regional impact of indonesian biomass burning emissions based on organic molecular tracers and chemical mass balance modeling

2014 ◽  
Vol 14 (15) ◽  
pp. 8043-8054 ◽  
Author(s):  
G. Engling ◽  
J. He ◽  
R. Betha ◽  
R. Balasubramanian
Keyword(s):  
Air Quality ◽  
Mass Balance ◽  
Biomass Burning ◽  
Large Scale ◽  
Chemical Species ◽  
Biomass Combustion ◽  
Diagnostic Ratios ◽  
Chemical Mass Balance ◽  
Haze Episode ◽  
Molecular Tracers

Abstract. Biomass burning activities commonly occur in Southeast Asia (SEA), and are particularly intense in Indonesia during the dry seasons. The effect of biomass smoke emissions on air quality in the city state of Singapore was investigated during a haze episode in October 2006. Substantially increased levels of airborne particulate matter (PM) and associated chemical species were observed during the haze period. Specifically, the enhancement in the concentration of molecular tracers for biomass combustion such as levoglucosan by as much as two orders of magnitude and the diagnostic ratios of individual organic compounds indicated that biomass burning emissions caused a regional smoke haze episode due to their long-range transport by prevailing winds. With the aid of air mass backward trajectories and chemical mass balance modeling, large-scale forest and peat fires in Sumatra and Kalimantan were identified as the sources of the smoke aerosol, exerting a significant impact on air quality in downwind areas, such as Singapore.

Fires in temperate peatlands (southern Quebec): past and recent trends

2007 ◽  
Vol 85 (3) ◽  
pp. 263-272 ◽  
Author(s):  
Claude Lavoie ◽  
Stéphanie Pellerin
Keyword(s):  
Fire History ◽  
Fire Regime ◽  
Fire Frequency ◽  
Time Interval ◽  
Temperate Region ◽  
Forest Expansion ◽  
Short Period ◽  
History Of ◽  
Recent Trends

In this study, we reconstructed the long-term fire history of a set of ombrotrophic peatlands (bogs) located in a temperate region of southern Quebec (Bas-Saint-Laurent). Past and recent fire-free intervals (time interval between two consecutive fires) were compared using macrofossil analyses. During most of the Holocene epoch, fires were relatively rare events in bogs of the Bas-Saint-Laurent region. The fire-free intervals were approximately ten times longer (all sites considered) before the beginning of agricultural activities in the region (1800 AD) than after. This strongly suggests an anthropogenic influence on the fire regime prevailing in the bogs over the last 200 years. However, the shortening of the fire-free intervals was mainly the result of the ignition of one or two fires in almost every site during a relatively short period (200 years), rather than a higher fire frequency in each of the bogs. In some cases, fires had an influence on the vegetation structure of bogs, but it is more likely that a combination of several disturbances (fire, drainage, and drier than average summers) favoured the establishment of dense stands of pine and spruce, a forest expansion phenomenon that is now widespread in temperate bogs.

scholarly journals Unraveling Long-Term Flood Risk Dynamics Across the Murray-Darling Basin Using a Large-Scale Hydraulic Model and Satellite Data

2022 ◽  
Vol 3 ◽  
Author(s):  
Serena Ceola ◽  
Alessio Domeneghetti ◽  
Guy J. P. Schumann
Keyword(s):  
Flood Risk ◽  
Large Scale ◽  
Flood Hazard ◽  
Spatial Scales ◽  
Mitigation Strategies ◽  
Economic Losses ◽  
Human Society ◽  
Murray Darling Basin ◽  
Flooded Areas

River floods are one of the most devastating extreme hydrological events, with oftentimes remarkably negative effects for human society and the environment. Economic losses and social consequences, in terms of affected people and human fatalities, are increasing worldwide due to climate change and urbanization processes. Long-term dynamics of flood risk are intimately driven by the temporal evolution of hazard, exposure and vulnerability. Although needed for effective flood risk management, a comprehensive long-term analysis of all these components is not straightforward, mostly due to a lack of hydrological data, exposure information, and large computational resources required for 2-D flood model simulations at adequately high resolution over large spatial scales. This study tries to overcome these limitations and attempts to investigate the dynamics of different flood risk components in the Murray-Darling basin (MDB, Australia) in the period 1973–2014. To this aim, the LISFLOOD-FP model, i.e., a large-scale 2-D hydrodynamic model, and satellite-derived built-up data are employed. Results show that the maximum extension of flooded areas decreases in time, without revealing any significant geographical transfer of inundated areas across the study period. Despite this, a remarkable increment of built-up areas characterizes MDB, with larger annual increments across not-flooded locations compared to flooded areas. When combining flood hazard and exposure, we find that the overall extension of areas exposed to high flood risk more than doubled within the study period, thus highlighting the need for improving flood risk awareness and flood mitigation strategies in the near future.

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