Home | People | Research | Projects | School of Geographical Sciences

Spy glass

Global Palaeofire Working Group logo

On this page: Planned analyses with GCDv1 | Completed analyses

PLANNED ANALYSES WITH THE GLOBAL CHARCOAL DATABASE (GCD v1)

Variability in fire regimes during the last glacial period
The "rules of fire": lessons from the palaeorecord
Fire regimes in the British Isles during the Holocene
Benchmarking the PMIP climate simulations using charcoal data
Simulated fire regimes at the Last Glacial Maximum and for the Mid-Holocene
Relationships between Vegetation and Fire for North America
Fire and vegetation during the spread of agriculture in the Near East and Europe
Relationships between Vegetation, Fire and Humans for Australia
Fire in the Americas, 1492 AD
European fire regimes at 8.2ka

To add research topics: Please notify Mitchell Power


Variability in fire regimes during the last glacial period

Contact: Anne-Laure Daniau

The QUEST Working Group on Abrupt Climate Changes (website) is currently synthesising vegetation records showing millennial-scale variability during MIS 3 and 4, and are interested in whether there are records of changes in vegetation disturbance regimes. There are more than 80 charcoal records in GCD Version 2 which extend beyond the Last Glacial Maximum into Stage 3 and 4. We plan to conduct a preliminary analysis of these records to determine whether there are significant changes in fire regimes during the glacial period, and whether these can be correlated with vegetation changes.


The "rules of fire": lessons from the palaeorecord

Contact: Sandy Harrison

There are some very clear messages emerging from GPWG publications about the climate controls on fire regimes. These messages have direct relevance to what might happen in the future and also to questions about how we manage fire. We will provide a clear summary of our emerging knowledge of the controls on fire regimes, aimed specifically at policy makers.

Return to top


Fire regimes in the British Isles during the Holocene

Contacts: Claire Jones and Richard Bradshaw

Charcoal fragments have been recorded from a variety of Holocene sediments and deposits in the British Isles, with most data from northern and western regions. We are collating these data from a dispersed literature with the aim of mapping charcoal deposition, analysing distribution patterns in space and time and testing hypotheses about the major drivers of fire in the region. We will try to separate the roles of human impact, climate and fuel characteristics using techniques of data-model comparison.

Return to top


Benchmarking the PMIP climate simulations using charcoal data

Contacts: Sandy Harrison and Jenn Marlon

Multiple coupled ocean-atmosphere models have been run with identical forcing for the Last Glacial Maximum and the Mid-Holocene in the Palaeoclimate Modelling Intercomparison Project (PMIP II). We will explore the potential for using version 2 of the GPWG charcoal database for evaluating these models, focusing on whether the data can be used to discriminate between the models, by running offline simulations with the coupled vegetation-fire model LPJ-SPITFIRE-V2 driven by output from each individual climate model.

Return to top


Simulated fire regimes at the Last Glacial Maximum and for the Mid-Holocene

Contacts: Jenn Marlon and Sandy Harrison

We will investigate changes in fire regime at the last Glacial Maximum (21,000 yr B.P) and during the Mid-Holocene (6000 yr B.P.) using the coupled vegetation-fire model LPJ-SPITFIRE-V2. LPJ-SPITFIRE-V2 will be driven by climate output from palaeoclimate simulations made within the framework of the Palaeoclimate Modelling Intercomparison Project (PMIP II). Specifically, we will use an ensemble average of the results of all the coupled ocean-atmosphere simulations made for each time period. The simulated patterns of vegetation and fire will be evaluated using Version 2 of the GPWG charcoal database. The aim of this exercise will be to determine the degree to which observed patterns of change in regional fire regimes can be explained by changes in glacial and mid-Holocene boundary conditions.

We will hold a workshop to make the proposed data-model comparisons in Spring 2009. If you are interested in being involved in this workshop, please contact Sandy Harrison.

Return to top


Relationships between Vegetation and Fire for North America

Contact: Jenn Marlon

We are investigating postglacial relationships between fire, vegetation and climate in North America through syntheses of high-resolution charcoal data and associated pollen data. High-resolution charcoal records from the Global Charcoal Database are used to examine trends in biomass burning and patterns of fire frequency in North America since deglaciation. Extreme fire events in the past are also investigated in detail. The charcoal data are examined in conjunction with fossil pollen data from the North American Pollen Database (NAPD) to better understand the controls on changes in fire activity. Results from this research are expected to confirm a strong connection between fire-regime changes and shifts in vegetation and climate.

Return to top


Fire and vegetation during the spread of agriculture in the Near East and Europe

Contact: Carlos Cordova

Archaeological and archaeobotanical data provide a comprehensive chronology of agricultural diffusion from the domestication foci in the Near East and the Eastern Mediterranean through Europe. Clearing for agricultural fields may have required extensive burning of vegetation, particularly in the more forested regions. This study will compare the timing of rapid increase of fires provided by the charcoal database, pollen data, and radiocarbon dates of the earliest agricultural sites in the various regions of the Mediterranean and Europe. The main analysis will focus on the period spanning from 10,000 (approximate date agriculture origins in the Levant) to about 5,000 years ago (agriculture reaches north-western Europe). Analyses of later periods may be interesting in terms of understanding fire and agricultural development during the Roman period and the Middle Ages.

The methodology used in this analysis will be useful also for similar studies of fire and agricultural diffusion in Africa and the Americas.

Return to top


Relationships between Vegetation, Fire and Humans for Australia

Contact: Scott Mooney

Australia includes some of the most fire-prone landscapes on Earth and bushfires are Australia's worst natural hazard in terms of loss of life. A variety of responses to fire by the flora demonstrates its importance over evolutionary time, and it is essential for the continuation of many species. Due to this importance, fire is a fundamental tool of conservation and management but also an extremely contentious issue given the divergent objectives of conservation and risk minimization. How climate and climate variability influences fire activity in Australian landscapes is unclear, but has considerable significance to the current and future management of fire. Ideas about the use of fire by Aboriginal people in pre-European Australia also continue to influence the debate. This project will synthesize existing data (and identify gaps) concerning climate, vegetation and fire in Australia during approximately the last 70,000 years towards two major aims: What is the relationship between fire and climate at various temporal scales? and, How have people, both pre-historic (Aboriginal) and historic (European), influenced fire in the past?

Return to top


Fire in the Americas, the 1492 AD hypothesis

Contact: Mitchell Power and Francis Mayle

During the Holocene, the last 11,000 years, climate, vegetation, and likely, humans have been key controls to changing fire regimes in the Americas. A long-accepted paradigm is that of the 'noble savage', whereby indigenous peoples lived in harmony within a pristine wilderness, with little or no significant impact upon natural ecosystems. However, increasing evidence for extensive, large-scale landscape modification is leading many archaeologists to argue that the very notion of 'virgin' forests is a myth, and that prior to the Spanish Conquest, forests, grasslands, and savannas were heavily managed using fire, transforming a once pristine wilderness into a 'cultural parkland' (Heckenberger et al. 2003). According to this theory, the 'pristine wilderness' first encountered by Europeans was in fact secondary forest recovering after the catastrophic crash in indigenous populations caused by first exposure to European diseases that swept through the Americas in advance of European settlers (Mann, 2006). If true, then fire frequencies would be expected to be significantly lower in the 16 and 17th centuries compared with the 15th century. We aim to test this hypothesis using data from the recently created Global Charcoal Database, analyzing charcoal data from throughout the Americas.

Return to top


Response of European fire regimes to short-term and abrupt climate changes during early Holocene

Contact: Boris Vanniere and Mitchell Power

Several short-term climatic fluctuations during the early Holocene in Europe have been identified in ecosystem dynamics and hydrological records (e.g. PBOs, Björck et al., 1997, Magny et al., 2007; Sapropel 1, Ariztegy et al., 2000; 8.2 ka, Alley and Agustsdottir, 2005; CE-4, Haas et al., 98). These fluctuations could have impacted European fire regimes and changing the role of fire on the landscape. By estimating fire regime response to short climatic events, we are examining how the regional fire regimes have been affected within the context of the long term climatic tendencies in Europe during the Holocene. Specifically we hypothesize that climate forcing during abrupt events resulted in regionally coherent responses in fire regimes. For example, climatic controls of fire within the Mediterranean region, resulting in aridification, are compared to climatic controls of the North Atlantic region, resulting in increasing moisture availability over northern Europe and Scandinavia.

To add research topics: Please notify Mitchell Power

COMPLETED ANALYSES

Younger Dryas / Comet Hypothesis in North America
Impact of a drier early-mid Holocene climate upon Amazonian forests


Younger Dryas / Comet Hypothesis in North America

Contact: Jenn Marlon

View paper

Summary of aims: A major controversy has arisen over the cause of the Younger Dryas (YD) climate reversal about 13,000 years ago. Until recently, the leading theory linked the onset of the rapid climate change with a sudden draining of fresh water from Lake Agassiz along the southern edge of the Laurentide ice sheet into the North Atlantic. The cold, fresh water influx slowed the ocean circulation system that transports heat poleward to the mid-latitudes and caused widespread cooling. Recent research by Firestone et al. (PNAS, 2007), however, provides evidence for a giant comet impact 12,900 years ago, coincident with the beginning of the YD chronozone (YDC). Firestone et al. argue that the impact, which probably occurred over Canada, triggered the meltwater outflow from the proglacial lakes and melting ice sheet. They also propose that explosion-related effects, including severe continent-wide wildfires led to the extinction of the North American megafauna and the disappearance of the Clovis hunters. Investigating and ultimately resolving this issue is essential for understanding how the Younger Dryas cold period began, what environmental effects were associated with the trigger, and how the changes were transmitted through the global climate system. The proposed research uses sedimentary charcoal data from lakes, bogs and soils at non-archaeological sites to (1) look for evidence of widespread, severe wildfires at 12,900 cal yr BP; and (2) examine the spatial distribution and sequence of changes in biomass burning at any sites that register high fire activity during the YD.

Return to top


Impact of a drier early-mid Holocene climate upon Amazonian forests

Contacts: Francis Mayle and Mitchell Power

View paper

Summary of aims: This research uses palaeoecological approach to examine the impact of drier climatic conditions of the early-mid Holocene (ca. 8000 to 4000 years ago) upon Amazonia's forest and their fire regimes. Palaeovegetation (pollen) and palaeofire (charcoal) records were synthesized from 20 sites (not all contain charcoal) within the present tropical forest biome. Our analysis shows the forest biome in most parts of Amazonia appears to have been remarkably resilient to climatic conditions significantly drier than those of today, despite widespread evidence of forest burning in the middle and late Holocene.

Return to top