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New tools in reconstructing wildfire history from sedimentary records using organic geochemical methods

English title New tools in reconstructing wildfire history from sedimentary records using organic geochemical methods
Applicant Schmidt Michael W. I.
Number 134452
Funding scheme Project funding (Div. I-III)
Research institution Geographisches Institut Universität Zürich
Institution of higher education University of Zurich - ZH
Main discipline Pedology
Start/End 01.05.2011 - 30.04.2014
Approved amount 189'296.00
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All Disciplines (2)

Discipline
Pedology
Geochemistry

Keywords (9)

fire history; organic geochemistry; lake sediments; Australia; pyrogenic carbon; fire-derived carbon; black carbon; Australia; charcoal

Lay Summary (English)

Lead
Lay summary

Cs) and thereconstruction of the past vegetation (pollen). Quantifying only(microscopically) visible charcoal may reflect charcoal from forest fires whichare relatively large in size and structurally sound. However these techniquesare less likely to quantify smaller charcoal fractions derived from grasses -probably the main contributor of charcoal in Australia’s vast savannas and opengrassy woodlands.137Pb, 210C, 14The fire regimes ofAustralia, the most fire prone continent on earth, have been changing duringthe late Quaternary and up to the present under the influence of a changingclimate and vegetation, Aboriginal impact and then by European settlers.Because fire history is an important parameter in understandingpalaeoenvironmental conditions in many parts of the world, it has beenreconstructed primarily by palynologists using lake cores and traditional tools(visible charcoal), combined with dating (

Therefore, we aredeveloping a new methodology to infer past wildfires by using geochemical toolsthat potentially assess the whole range of fire residues in sedimentary recordsand that can yield additional information about the vegetation burned. Inparticular, we propose that a geochemical marker method (benzene polycarboxylicacids (BPCA)) would be capable to detect sedimentary fire residues that are toosmall to detect with standard microscopic methods. So far, however, thesegeochemical markers have not been used to quantify fire residues in lakesediment cores, neither have they been cross-compared to the presence ofvisible charcoal, which is indicative of palaeofires.

The proof-of-concept studyis conducted at two Australian sites where we would use molecular markers(BPCA) together with other geochemical methods to quantify past occurrences offire and burned vegetation types. First we screen samples from about 200 depthintervals with a relatively rapid technique (MIR-PLS, mid-infrared spectroscopywith partial least square analysis) to observe major organic and inorcanicproperties. Then, an in-depth, and more time-consuming characterization followson some 20 samples from those sections of the cores, which have been identifiedby MIR-PLS to show significant changes in charcoal and organic carbonabundance. These sections will be analyzed using more sophisticated molecularscale techniques including the BPCA molecular marker method.

To summarize, the project takes up three tasks. 1. We systematicallycompare available organic geochemical tools to the palynological methodologyand try to decipher more information about fire history out of sedimentaryrecords. 2. More concretely, we want to test the hypothesis whether Australia’sHolocene fire record is biased towards forest fires and consequentlyunderestimates the contribution of grassland fires to the fire record andAustralia’s charcoal pool. 3. The methodology used has the potential to becomea quantitative approach to reconstruct wildfires. We will therefore try tosimplify the procedure for a straightforward use in the palaeosciencecommunity, for which it could be a valuable tool for future palaeofirereconstructions.

Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Characterization, quantification and compound-specific isotopic analysis of pyrogenic carbon using benzene polycarboxylic acids (BPCA)
Wiedemeier D. B. Lang S. Q. Gierga M. Abiven S. Bernasconi S. M. Früh-Green G. L. Hajdas (2016), Characterization, quantification and compound-specific isotopic analysis of pyrogenic carbon using benzene polycarboxylic acids (BPCA), in Journal of Visualized Experiments (JoVE), e53922(111), http://www-http://www.
Purification of fire-derived markers for µg scale isotope analysis (δ13C, Δ14C) using high-performance liquid chromatography (HPLC)
Gierga Schneider Wiedemeier Lang Smittenberg Hajdas Bernasconi Schmidt (2014), Purification of fire-derived markers for µg scale isotope analysis (δ13C, Δ14C) using high-performance liquid chromatography (HPLC), in Organic Geochemistry, 70, 1-9.
Improved assessment of pyrogenic carbon quantity and quality in environmental samples by high-performance liquid chromatography
Daniel B. Wiedemeier Michael D. Hilf Rienk H. Smittenberg Simon G. Haberle Michael W.I. Schmidt (2013), Improved assessment of pyrogenic carbon quantity and quality in environmental samples by high-performance liquid chromatography, in Journal of Chromatography A, 1304, 246-250.

Collaboration

Group / person Country
Types of collaboration
Australian National University Australia (Oceania)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Baylor University United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
ETH Zürich Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
- Exchange of personnel
Oregon State University United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
University of Bern Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
Lawrence Berkeley Lab United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
University of Adelaide Australia (Oceania)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Rice University United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
American Geoscience Union (AGU) Fall Meeting Poster Aromaticity and the degree of aromatic condensation of pyrogenic carbon 09.12.2013 San Francisco, United States of America Wiedemeier Daniel; Schmidt Michael W. I.;
26th International Meeting on Organic Geochemistry (IMOG) Poster Aromaticity and the degree of aromatic condensation of chars 16.09.2013 Tenerife, Spain Schmidt Michael W. I.; Wiedemeier Daniel;
Jahrestagung der Deutschen Bodenkundlichen Gesellschaft 2013 Poster Improved assessment of pyrogenic carbon in soils by liquid chromatography 07.09.2013 Rostock, Germany Wiedemeier Daniel; Schmidt Michael W. I.;
European Geoscience Union (EGU) – General Assembly 2013 Poster A method comparison to infer charring temperature, aromaticity and the degree of condensation of pyrogenic carbon 07.04.2013 Vienna, Austria Schmidt Michael W. I.; Wiedemeier Daniel;
European Geoscience Union (EGU) – General Assembly 2013 Poster Improved assessment of pyrogenic carbon quantity and quality in soils by liquid chromatography 07.04.2013 Vienna, Austria Wiedemeier Daniel; Schmidt Michael W. I.;
Jahrestagung der Bodenkundlichen Gesellschaft Schweiz (BGS) Talk given at a conference Improved assessment of pyrogenic carbon quantity and quality in soils by liquid chromatography 07.02.2013 Reckenholz, Switzerland Wiedemeier Daniel; Schmidt Michael W. I.;
5th International Workshop on Soil and Sedimentary Organic Matter Stabilization and Destabilization (SOM5) Poster Improved quantification of pyrogenic carbon in soils and sediments by a HPLC-DAD method 07.10.2012 Ascona, Switzerland Schmidt Michael W. I.; Wiedemeier Daniel;
4th international Congress of the European Confederation of Soil Science Societies (EUROSOIL) Talk given at a conference Improved quantification of pyrogenic carbon in soils by a HPLC-DAD method 02.07.2012 Bari, Italy Schmidt Michael W. I.; Wiedemeier Daniel;
European Geoscience Union (EGU) – General Assembly 2012 Talk given at a conference Improved quantification of pyrogenic carbon in environmental samples – the use of HPLC to quantify BPCAs in matrix samples 22.04.2012 Vienna, Austria Schmidt Michael W. I.; Wiedemeier Daniel;
25th International Meeting on Organic Geochemistry (IMOG) Poster New molecular marker and spectroscopic tools for reconstructing wildfire history 18.09.2011 Interlaken, Switzerland Schmidt Michael W. I.; Wiedemeier Daniel;
18th International Union for Quaternary Research (INQUA) Congress Talk given at a conference New molecular marker and spectroscopic tools for reconstructing wildfire history 21.07.2011 Bern, Switzerland Schmidt Michael W. I.; Wiedemeier Daniel;


Awards

Title Year
Best presentation at International Soil Organic Matter workshop (SOM 5), Ascona, 2012. 2012
Young Scientist Travel Award by ESF (European Science Foundation) Network MOLTER 2011

Associated projects

Number Title Start Funding scheme
157778 Next-Iso: Next generation compound-specific isotope analysis of stable and radioactive isotopes of organic components in terrestrial ecosystems 01.02.2015 R'EQUIP

Abstract

The fire regimes of Australia have been changing during the late Quaternary and up to the present under the influence of a changing climate and vegetation, Aboriginal impact and then by European settlers. Because fire history is an important parameter in understanding palaeoenvironmental conditions, it has been reconstructed primarily by palynologists using lake cores and traditional tools (visible charcoal), combined with dating (14C, 210Pb, 137Cs) and the reconstruction of the past vegetation (pollen). Quantifying only (microscopically) visible charcoal may reflect charcoal from forest fires which are relatively large in size and structurally sound. However these techniques are less likely to quantify smaller charcoal fractions derived from grasses - probably the main contributor of charcoal in Australia’s vast savannas and open grassy woodlands. Therefore, we suggest here the development of a new methodology to infer past wildfires by using geochemical tools that potentially assess the whole range of fire residues in sedimentary records and that can yield additional information about the vegetation burned.In particular, we propose that a geochemical marker method (benzene polycarboxylic acids (BPCA)) would be capable to detect sedimentary fire residues that are too small to detect with standard microscopic methods. BPCA have been used for almost a decade as unambiguous and quantitative molecular markers for the presence of fire-derived organic matter in soil, and in a recent laboratory ring trial have been proven to be a robust and quantitative tool for charcoal quantification. So far, however, these geochemical markers have not been used to quantify fire residues in lake sediment cores, neither have they been cross-compared to the presence of visible charcoal.The proposed proof-of-concept study would be conducted at two Australian sites where we would use molecular markers (BPCA) together with other geochemical methods to quantify past occurrences of fire and burned vegetation types. We would have access to already existing, pre-characterized cores, one from the tropical north near Cairns (Quincan Crater), and one from the temperate south (Bega Swamp), 300 km south of Sydney. First we would screen samples from about 200 depth intervals with a relatively rapid technique (MIR-PLS, mid-infrared spectroscopy with partial least square analysis) to observe major organic and inorcanic properties.Then, an in-depth, and more time-consuming characterization would follow on some 20 samples from those sections of the cores, which have been identified by MIR-PLS to show significant changes in charcoal and organic carbon abundance. These sections will be analyzed using more sophisticated molecular scale techniques including the BPCA molecular marker method and 13C-NMR (nuclear magnetic resonance) spectroscopy. Most importantly, both tools (BPCA and 13C-NMR) do not rely on the counting of visible remains, but directly (and independently of each other) are able to quantify the presence of fire residues in the samples. This would be a novel approach, which has not yet been tried in palynology and stratigraphy. In a next step, we would determine the stable isotope composition of individual BPCA, which would tell us if these are derived from grass (mostly C4 vegetation with high d13C values) and/or from forest (mostly C3 vegetation with low d13C values). Also this has not yet been attempted so far. To summarize, the proposed project takes up three tasks. 1. For the first time, we would systematically compare available organic geochemical tools to the palynological methodology and try to decipher more information about fire history out of sedimentary records. 2. More concretely, we want to test the hypothesis whether Australia’s Holocene fire record is biased towards forest fires and consequently underestimates the contribution of grassland fires to the fire record and Australia’s charcoal pool. 3. The methodology used has the potential to become a quantitative approach to reconstruct wildfires. We will therefore try to simplify the procedure for a straightforward use in the palaeoscience community, for which it could be a valuable tool for future palaeofire reconstructions.
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