Crosscutting Initiatives

Crosscutting Initiative 1: Asian & Africa paleofire challenges

Coordinator Mitchell Power, University of Utah, USA

The “geographical challenge” is a crosscutting initiative in the GPWG2 activities that has to be considered as a critical point in the geographical development of the GPWG network and scientific activities within the next three years. More important than simply expanding the coverage of the global charcoal database is the ability to extract meaningful information and address the key questions about fire-related issues over the world and in particular from fire-prone regions on earth such as Africa and Asia.Read more

 Two major challenges are emerging from the global syntheses of fire regimes: 1) establishing sub-continental to regional patterns in fire regimes that can be understood in relation to modern fire activities, and 2) identifying the dominant controls (e.g. climate, vegetation and humans) of fire during the late Quaternary in each region. Indeed, to propose a long-term global biomass burning reconstruction that is comparable with remote sensing or modelled fire related data, it is essential to have a good representation of the world and understand regional specificity. The Global Charcoal Database contains approximately 50-60% of the available charcoal records and continued development of this database is widely supported by the paleo community. The database serves as a crucial resource for benchmarking simulations driven by climate output from coupled ocean-atmosphere general circulation models and/ or land cover models (e.g. the Paleoclimate Modelling Intercomparison Project – PMIP3; The LandCover6K PAGES project). Therefore, we have recently released version 3 of the global charcoal database, containing over ~730 records used in our global synthesis (Marlon et al. accepted in Biogeosciences Discussion). Several regions have subsequently been identified as significant gaps in the current version of the database, including Africa and Asia where only 20% of records are available in the GCD for these two continents. To accomplish this goal, regional workshops will help collate and analyze data from these regions. Participation in international conferences and publication of the GCD will continue to encourage scientists to lead new data collection efforts from Asian and Africa regions. The major implementation mode for the continued growth of paleofire activities will be through regionally targeted thematic workshops. These regional fire workshops will focus on the fulfil the significant gaps in data coverage through detailed examination of model predictions, data collection and techniques teaching, but also highlighting regional fire issues in connection regional stakeholders according to the A, B, and C Focus Groups aims and goals. The workshop may have a significant capacity-building component and it is hoped that it will inspire new work on paleofire across the continents.

Two workshops are planned in 2017 and 2018:

October 2017 (Nairobi, Kenya): Workshop theme: Paleofires in Savanna. The aim of the workshop is to strengthen collaborations with scientists and stakeholders from this region. This workshop will explore also the interactions of the savannah ecosystems with fire regimes on long time scales. Scientists in charge of organization: Rebecca Muthoni (National Museum of Kenya) and Mitchell Power (University of Utah). Potential Funding Sources: EAQUA, NSF.

September 2018 (Xi’an, China): Workshop theme: Fire regimes under the Asian Monsoon. The aim of the workshop is to strengthen collaborations with scientists and stakeholders from this region. This workshop will explore also the role of the Asian Monsoon influencing fire regimes on long time scales. Scientists in charge of organization: Zhihai Tan (State Key Laboratory of Loess and Quaternary Geology, Chinese Academy of Science) and Mitchell Power (University of Utah) Potential Funding Sources: Chinese Academy of Science, NSF.

Crosscutting Initiative 2: Syntheses and database development

Coordinator Boris Vannière, CNRS, Université de Franche Comté, France

Collecting, extracting, analyzing and disseminating meaningful paleoclimate and environmental data, such as paleofire reconstructions from the global charcoal database, is paramount to the PAGES mission of documenting and analyzing past climate change. The aim of the Global Charcoal Database (GCD) is to provide the scientific community a global paleofire dataset for research and archiving sedimentary records of fire. The GCD contains site and sample metadata that when used in conjunction with information about changes in vegetation distribution, yields explicit information about vegetation productivity, changes in fuel load and the completeness of burn – all of which would provide a strong constraint on simulated fire regimes and emissions. In combination with archaeological data, the charcoal records can also be used to explore the role of humans in modifying natural fire regimes. Read more

 The primary goal of this crosscutting initiative is to continue expanding the GCD by identifying and compiling new fire history records, but more importantly by improving the accessibility and usability of this resource. The GCD now serves both as a research tool for the paleofire, environmental, and climate researchers, and as a new source of information for landscape managers and stakeholders. The GCD (version 1, 2 and 3) is currently provided as a Microsoft Access database. In 2013 the GPWG steering committee started to develop the conceptual structure and architecture to move the Access database to a MySQL environment to improve data management, which was necessary as the number of records increases, and to improve accessibility of the database, which is essential to foster collaborations with modelers and fire practitioners. The easier it is to access the data, the more chances there are to interest a larger audience. We expect such increases will promote new analyses and unexpected uses of the data. This new environment will permit secure worldwide data contributors to directly add or update their own records online. It will also offer concurrent access, H24 access, a friendly graphical user interface, and a direct link to the paleofire and GCD R packages. It will permit automatic generation of charts and graphs, and several releases of new versions of the whole dataset. In 2015, importation of the GCD version 3 was performed in this new environment and the beta version is already accessible at We expect the beginning of 2016 to be a period where external users of the GCD can test the different functionalities of the new interface, and to publically release the GCD version 3.

We anticipate a new call for data contributions in 2016 for a future version 4 of the GCD, and in particular to cover geographical gaps, specifically in Africa and Asia (cross-cutting initiatives 1). Additionally, the development of a new module “mGCD” (modern Global Charcoal Database) is required to integrate new data for the calibration (see cross-cutting initiative 4 below). Therefore, different metadata information will be introduced in a systematic way, using common units based on international standards, morphology, particle size, the quantification method used to measure charcoal (image analysis, point-Clark method, etc.), and the processing method applied to the sediment to extract charcoal (sieving, pollen slide procedure, etc.). The goals and tools of this crosscutting initiative are an integral part of each Focus Group activities and workshops.

Crosscutting Initiative 3: Paleofire data-model integration and links with other databases.

Coordinator Jennifer Marlon, Yale Univ., USA

Fire activity has been characterized and analyzed at a wide range of spatial scales using data about past fires from field and historical observations, dendrochronological data, satellites, ice cores, and charcoal in sediments, coupled with information about climate, vegetation, human populations, and cultural practices. Collectively, this research aims to infer the nature, causes, and impacts of fires across spatial and temporal scales. Of the available fire proxies however, only syntheses of sediment records have provide both global spatial information and decadal-to-millennial temporal information about biomass burning during both gradual and abrupt climate changes, and during major historical shifts in human populations and societies (e.g., during the expansion of agriculture in the Holocene). As a result, paleofire research has greatly advanced our understanding of the linkages of fire to both climate and humans, as well as its role as a force of long-term global environmental change. Read more

 Fire modeling efforts have also advanced rapidly in the last decade to better understand the varied impacts that fires have on humans, the biosphere, and the atmosphere, as well as the mechanisms through which climate change and human activities determine fire regimes. Simulations of fire activity using physically-based empirical relationships between flammability and controlling variables, such as temperature and soil moisture, have helped identify the global drivers of modern-day fires. Fire modeling studies have also made qualitative comparisons of paleofire trends with simulated global fire activity. However quantitative testing of the physically-based relationships that drive fire models – the mechanics of the models themselves – has only been considered under modern climate conditions, leaving large gaps in our knowledge about how fire, climate, and humans interact outside modern climate parameters. In order to predict the response of fires to climate changes outside modern conditions, paleofire histories can and should be used to constrain fire model simulations, validate fire parameterization schemes, and test hypotheses about the interactions between fire, people, climate, and vegetation under a range of conditions.

The main goal of this cross-cutting initiative is to foster collaborations with fire modelers and with researchers with expertise on other databases. Specifically, we will 1) develop time series and gridded maps that can serve as benchmarks for model comparisons for key time periods and slices, including the Last Glacial Maximum (21kya), mid-Holocene (6kya), past millennium, and past century; 2) partner with the FireMIP (Fire Model Intercomparison Project) to test models for the selected time slices; 3) combine GCD data with pollen data from Neotoma, the EPD, APD, and other pollen databases to conduct data-model comparisons that allow us to test specific hypotheses about climate, vegetation, and human controls of broad-scale fire dynamics; and 4) develop tools to quickly integrate data from multiple databases using indices that link sites and locations despite discrepancies in how sites are named, geocoded, etc. in different source databases. Such efforts will be integrated into each of the Focus Group workshops, with representatives from different modeling labs and databases attending each of the events. 

Crosscutting Initiative 4: The modern Global Charcoal Database – mGCD

Coordinators: Donna Hawthorne, Ireland; Colin Courtney Mustaphi, UK; Julie Aleman, USA

The Early Career Researcher (ECR) project is driven by a group of young researchers that formed during the last GPWG workshop (October 2015, Harvard Forest) a crosscutting initiative to contribute to the future of the GPWG.

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 Charcoal produced by fire is due to the incomplete combustion of vegetal biomass, and is an important proxy for paleoenvironmental research, having many applications covering a multidisciplinary approach. Quantifying the amount of charcoal in sediment informs us about changes in biomass burning. However, paleofire records only provide measurements of relative changes in biomass burning because different units of measurement (concentration in particles or surface per gram, cm3, or influx, etc.) are used across diverse sediment environments. Calibration studies are therefore necessary to link the amount of charcoal found in sediments to the amount of biomass burning, fire emissions and burned surface area within the landscape. Surface sediment captures the most recent charcoal deposition from a catchment area and is an indicator of contemporary biomass burning. Surface sediment samples will also help in the understanding of transportation process and help to calibrate charcoal source area.

The ECR project will focus on developing an international protocol for collecting and analyzing different fire proxies (charcoal, levoglucosan and black carbon) from surface sediment samples around the globe using a standardized methodology and comparable units. The data will be integrated into the GCD through an initiative called the Modern Global Charcoal Database (mGCD). The archive will target a range of ecosystems and environments including but not limited to lacustrine and marine sediment, peat deposits and glacial archives. The project will be designed to become a citizen science initiative where everyone can contribute to the database by collecting surface sediment samples from appropriate sites, and send them to designated laboratories on each continent for processing and analyses.

Results from this initiative have a strong potential to transform paleofire research by allowing the rapid development of statistical models that can link charcoal accumulation rates to modern estimates or reconstructions of fire activity at a wide range of spatial scales and in many parts of the world. Reconstructions of biomass burning would no longer be limited to simplified estimates of relative burning, and could instead be used to estimate absolute levels of burning at least where data density is sufficient. Broad international support is essential for the success of this initiative, and early career researchers are the ideal sponsors for it because it should be an ongoing initiative that can develop for decades into the future if designed well at the outset.