[en] Charcoal is a heterogeneous material exhibiting a diverse range of properties. This variability represents a serious challenge in studies that use the properties of natural charcoal for reconstructing wildfires history in terrestrial ecosystems. In this study, we tested the hypothesis that particle size is a sufficiently robust indicator for separating forest wildfire combustion products into fractions with distinct properties. For this purpose, we examined two different forest environments affected by contrasting wildfires in terms of severity: an eucalypt forest in Australia, which experienced an extremely severe wildfire, and a Mediterranean pine forest in Italy, which burned to moderate severity. We fractionated the ash/charcoal layers collected on the ground into four size fractions (>2, 2–1, 1–0.5, <0.5 mm) and analysed them for mineral ash content, elemental composition, chemical structure (by IR spectroscopy), fuel source and charcoal reflectance (by reflected-light microscopy), and chemical/thermal recalcitrance (by chemical and thermal oxidation).
At both sites, the finest fraction (<0.5 mm) had, by far, the greatest mass. The C concentration and C/N ratio decreased with decreasing size fraction, while pH and the mineral ash content followed the opposite trend. The coarser fractions showed higher contribution of amorphous carbon and stronger recalcitrance. We also observed that certain fuel types were preferentially represented by particular size fractions. We conclude that the differences between ash/charcoal size fractions were most likely primarily imposed by fuel source and secondarily by burning conditions. Size fractionation can therefore serve as a valuable tool to characterise the forest wildfire combustion products, as each fraction displays a narrower range of properties than the whole sample. We propose the mineral ash content of the fractions as criterion for selecting the appropriate number of fractions to analyse.
Disciplines :
Life sciences: Multidisciplinary, general & others
Author, co-author :
Mastrolonardo, Giovanni ; Université de Liège > Ingénierie des biosystèmes (Biose) > Echanges Eau-Sol-Plantes
Language :
English
Title :
Size fractionation as a tool for separating charcoal of different fuel source and recalcitrance in the wildfire ash layer
2009 Victorian Bushfires Royal Commission, 2010 2009 Victorian Bushfires Royal Commission, Final Report. 2010, Government Printer for the State of Victoria, Melbourne, Australia http://pandora.nla.gov.au/pan/96781/20100923-0223/www.royalcommission.vic.gov.au/Commission-Reports/Final-Report/Summary.html.
Alexis, M.A., Rasse, D.P., Rumpel, C., Bardoux, G., Péchot, N., Schmalzer, P., Drake, B., Mariotti, A., Fire impact on C and N losses and charcoal production in a scrub oak ecosystem. Biogeochemistry 82 (2007), 201–216.
Alexis, M.A., Rumpel, C., Knicker, H., Leifeld, J., Rasse, D., Péchot, N., Bardoux, G., Mariotti, A., Thermal alteration of organic matter during a shrubland fire: a field study. Org. Geochem. 41 (2010), 690–697, 10.1016/j.orggeochem.2010.03.003.
Ascough, P., Bird, M., Wormald, P., Snape, C., Apperley, D., Influence of pyrolysis variables and starting material on charcoal stable isotopic and molecular characteristics. Geochim. Cosmochim. Acta 72 (2008), 6090–6102.
Ascough, P.L., Bird, M.I., Scott, A.C., Collinson, M.E., Cohen-Ofri, I., Snape, C.E., Le Manquais, K., Charcoal reflectance measurements: implications for structural characterization and assessment of diagenetic alteration. J. Archaeol. Sci. 37 (2010), 1590–1599, 10.1016/j.jas.2010.01.020.
Belcher, C.M., Hudspith, V.A., The formation of charcoal reflectance and its potential use in post-fire assessments. Int. J. Wildland Fire 25 (2016), 775–779, 10.1071/WF15185.
Bird, M.I., Ascough, P.L., Isotopes in pyrogenic carbon: a review. Org. Geochem. 42 (2012), 1529–1539, 10.1016/j.orggeochem.2010.09.005.
Bird, M.I., Gröcke, D.R., Determination of the abundance and carbon isotope composition of elemental carbon in sediments. Geochim. Cosmochim. Acta 61 (1997), 3413–3423, 10.1016/S0016-7037(97)00157-9.
Bodí, M.B., Martin, D.A., Balfour, V.N., Santín, C., Doerr, S.H., Pereira, P., Cerdà, A., Mataix-Solera, J., Wildland fire ash: production, composition and eco-hydro-geomorphic effects. Earth Sci. Rev., 2014, 10.1016/j.earscirev.2013.12.007.
Brook, A., Wittenberg, L., Ash-soil interface: mineralogical composition and physical structure. Sci. Total Environ., 2016 (Ahead of Print) 10.1016/j.scitotenv.2016.02.123.
Certini, G., Nocentini, C., Knicker, H., Arfaioli, P., Rumpel, C., Wildfire effects on soil organic matter quantity and quality in two fire-prone Mediterranean pine forests. Geoderma 167–168 (2011), 148–155, 10.1016/j.geoderma.2011.09.005.
Chafer, C.J., Noonan, M., Macnaught, E., The post-fire measurement of fire severity and intensity in the Christmas 2001 Sydney wildfires. Int. J. Wildland Fire 13 (2004), 227–240, 10.1071/WF03041.
Doerr, S.H., Shakesby, R.A., Smith, H.G., Sheridan, G.J., Lane, N.J., Bell, T., Blake, W.H., The catastrophic Victoria fires of 2009: extreme fire intensity, but only moderate soil burn severity? Reconstructing fire behaviour from soil, ash and seedbank survival data, Proceedings of the 6th International Conference on Forest Fire Research, 15–18th Nov. 2010, Coimbra, Portugal. Paper #279, 2010.
Eckmeier, E., Gerlach, R., Skjemstad, J.O., Ehrmann, O., Schmidt, M.W.I., Minor changes in soil organic carbon and charcoal concentrations detected in a temperate deciduous forest a year after an experimental slash-and-burn. Biogeosciences 4 (2007), 377–383, 10.5194/bg-4-377-2007.
Forbes, M.S., Raison, R.J., Skjemstad, J.O., Formation, transformation and transport of black carbon (charcoal) in terrestrial and aquatic ecosystems. Sci. Total Environ. 370 (2006), 190–206, 10.1016/j.scitotenv.2006.06.007.
Francioso, O., Sanchez-Cortes, S., Bonora, S., Roldán, M.L.M.L., Certini, G., Structural characterization of charcoal size-fractions from a burnt Pinus pinea forest by FT-IR, Raman and surface-enhanced Raman spectroscopies. J. Mol. Struct. 994 (2011), 155–162, 10.1016/j.molstruc.2011.03.011.
González-Pérez, J.A., González-Vila, F.J., Almendros, G., Knicker, H., The effect of fire on soil organic matter-a review. Environ. Int. 30 (2004), 855–870, 10.1016/j.envint.2004.02.003.
Guo, Y., Bustin, R.M., FTIR spectroscopy and reflectance of modern charcoals and fungal decayed woods: implications for studies of inertinite in coals. Int. J. Coal Geol. 37 (1998), 29–53, 10.1016/S0166-5162(98)00019-6.
Halofsky, J.E., Hibbs, D.E., Determinants of riparian fire severity in two Oregon fires, USA. Can. J. For. Res. 38 (2008), 1959–1973, 10.1139/X08-048.
Harvey, O.R., Kuo, L.J., Zimmerman, A.R., Louchouarn, P., Amonette, J.E., Herbert, B.E., An index-based approach to assessing recalcitrance and soil carbon sequestration potential of engineered black carbons (biochars). Environ. Sci. Technol. 46 (2012), 1415–1421, 10.1021/es2040398.
Hatton, P.-J., Chatterjee, S., Filley, T.R., Dastmalchi, K., Plante, A.F., Abiven, S., Gao, X., Masiello, C.A., Leavitt, S.W., Nadelhoffer, K.J., Stark, R.E., Bird, J.A., Tree taxa and pyrolysis temperature interact to control the efficacy of pyrogenic organic matter formation. Biogeochemistry 130 (2016), 103–116, 10.1007/s10533-016-0245-1.
Hudspith, V.A., Belcher, C.M., Yearsley, J.M., Charring temperatures are driven by the fuel types burned in a peatland wildfire. Front. Plant Sci., 5, 2014, 714, 10.3389/fpls.2014.00714.
Kaufman, J.H., Metin, S., Saperstein, D.D., Symmetry breaking in nitrogen-doped amorphous carbon: infrared observation of the Raman-active G and D bands. Phys. Rev. B, 39, 1989, 13053.
Knicker, H., Hilscher, A., González-Vila, F.J., Almendros, G., A new conceptual model for the structural properties of char produced during vegetation fires. Org. Geochem. 39 (2008), 935–939, 10.1016/j.orggeochem.2008.03.021.
Knox, K.J.E., Clarke, P.J., Measuring fire severity: are canopy, understorey and below-ground measures coupled in sclerophyll forest fires?. Plant Ecol. 217 (2016), 607–615, 10.1007/s11258-016-0609-6.
Madejová, J., FTIR techniques in clay mineral studies. Vib. Spectrosc. 31 (2003), 1–10, 10.1016/S0924-2031(02)00065-6.
Masiello, C.A., New directions in black carbon organic geochemistry. Mar. Chem. 92 (2004), 201–213, 10.1016/j.marchem.2004.06.043.
Mastrolonardo, G., Rumpel, C., Forte, C., Doerr, S.H., Certini, G., Abundance and composition of free and aggregate-occluded carbohydrates and lignin in two forest soils as affected by wildfires of different severity. Geoderma 245–246 (2015), 40–51, 10.1016/j.geoderma.2015.01.006.
Mastrolonardo, G., Francioso, O., Di Foggia, M., Bonora, S., Forte, C., Certini, G., Soil pyrogenic organic matter characterisation by spectroscopic analysis: a study on combustion and pyrolysis residues. J. Soils Sediments 15 (2015), 769–780, 10.1007/s11368-014-1034-x.
McBeath, A.V., Smernik, R.J., Krull, E.S., A demonstration of the high variability of chars produced from wood in bushfires. Org. Geochem. 55 (2013), 38–44, 10.1016/j.orggeochem.2012.11.006.
Merino, A., Chávez-Vergara, B., Salgado, J., Fonturbel, M.T., García-Oliva, F., Vega, J.A., Variability in the composition of charred litter generated by wildfire in different ecosystems. Catena 133 (2015), 52–63, 10.1016/j.catena.2015.04.016.
Michelotti, L.A., Miesel, J.R., Source material and concentration of wildfire-produced pyrogenic carbon influence post-fire soil nutrient dynamics. Forests 6 (2015), 1325–1342, 10.3390/f6041325.
Nocentini, C., Certini, G., Knicker, H., Francioso, O., Rumpel, C., Nature and reactivity of charcoal produced and added to soil during wildfire are particle-size dependent. Org. Geochem. 41 (2010), 682–689, 10.1016/j.orggeochem.2010.03.010.
Ohlson, M., Dahlberg, B., Økland, T., Brown, K.J., Halvorsen, R., The charcoal carbon pool in boreal forest soils. Nat. Geosci. 2 (2009), 692–695, 10.1038/ngeo617.
Pansu, M., Gautheyrou, J., Handbook of Soil Analysis: Mineralogical, Organic and Inorganic Methods. 2006, Springer, New York.
Pyle, L.A., Hockaday, W.C., Boutton, T., Zygourakis, K., Kinney, T.J., Masiello, C.A., Chemical and isotopic thresholds in charring: implications for the interpretation of charcoal mass and isotopic data. Environ. Sci. Technol. 49 (2015), 14057–14064, 10.1021/acs.est.5b03087.
Randerson, J.T., Chen, Y., Van Der Werf, G.R., Rogers, B.M., Morton, D.C., Global burned area and biomass burning emissions from small fires. J. Geophys. Res. Biogeosci., 117, 2012, G04012, 10.1029/2012JG002128.
Reisser, M., Purves, R.S., Schmidt, M.W.I., Abiven, S., Pyrogenic carbon in soils: a literature-based inventory and a global estimation of its content in soil organic carbon and stocks. Front. Earth Sci. 4 (2016), 1–14, 10.3389/feart.2016.00080.
Rumpel, C., González-Pérez, J.A., Bardoux, G., Largeau, C., Gonzalez-Vila, F.J., Valentin, C., Composition and reactivity of morphologically distinct charred materials left after slash-and-burn practices in agricultural tropical soils. Org. Geochem. 38 (2007), 911–920, 10.1016/j.orggeochem.2006.12.014.
Santín, C., Doerr, S.H., Shakesby, R.A., Bryant, R., Sheridan, G.J., Lane, P.N.J., Smith, H.G., Bell, T.L., Carbon loads, forms and sequestration potential within ash deposits produced by wildfire: new insights from the 2009 “Black Saturday” fires, Australia. Eur. J. For. Res. 131 (2012), 1245–1253, 10.1007/s10342-012-0595-8.
Santín, C., Doerr, S.H., Kane, E., Masiello, C., Ohlson, M., Preston, C., de la Rosa, A., Dittmar, T., Towards a global assessment of pyrogenic carbon from vegetation fires. Glob. Chang. Biol. 22 (2016), 76–91, 10.1111/gcb.12985.
Santín, C., Doerr, S.H., Merino, A., Bryant, R., Loader, N.J., Forest floor chemical transformations in a boreal forest fire and their correlations with temperature and heating duration. Geoderma 264 (2016), 71–80, 10.1016/j.geoderma.2015.09.021.
Scott, A.C., Charcoal recognition, taphonomy and uses in palaeoenvironmental analysis. Palaeogeogr. Palaeoclimatol. Palaeoecol. 291 (2010), 11–39, 10.1016/j.palaeo.2009.12.012.
Tatzber, M., Stemmer, M., Spiegel, H., Katzlberger, C., Haberhauer, G., Mentler, A., Gerzabek, M.H., FTIR-spectroscopic characterization of humic acids and humin fractions obtained by advanced NaOH, Na4P2O7, and Na2CO3 extraction procedures. J. Plant Nutr. Soil Sci. 170 (2007), 522–529, 10.1002/jpln.200622082.
Wiechmann, M.L., Hurteau, M.D., Kaye, J.P., Miesel, J.R., Macro-particle charcoal C content following prescribed burning in a mixed-conifer forest, Sierra Nevada, California. PLoS One, 10, 2015, 10.1371/journal.pone.0135014.
Wiedemeier, D.B., Abiven, S., Hockaday, W.C., Keiluweit, M., Kleber, M., Masiello, C.A., McBeath, A.V., Nico, P.S., Pyle, L.A., Schneider, M.P.W., Smernik, R.J., Wiesenberg, G.L.B., Schmidt, M.W.I., Aromaticity and degree of aromatic condensation of char. Org. Geochem. 78 (2015), 135–143, 10.1016/j.orggeochem.2014.10.002.
