Data from: Does fuel type influence the amount of charcoal produced in wildfires? Implications for the fossil record
Hudspith, Victoria A., University of Exeter
Hadden, Rory M., University of Edinburgh
Bartlett, Alastair I., University of Edinburgh
Belcher, Claire M., University of Exeter
Published Oct 23, 2018 on Dryad.
Cite this dataset
Hudspith, Victoria A.; Hadden, Rory M.; Bartlett, Alastair I.; Belcher, Claire M. (2018). Data from: Does fuel type influence the amount of charcoal produced in wildfires? Implications for the fossil record [Dataset]. Dryad. https://doi.org/10.5061/dryad.g2fm2
Charcoal occurrence is extensively used as a tool for understanding wildfires over geological timescales. Yet, the fossil charcoal literature to date rarely considers that fire alone is capable of creating a bias in the abundance and nature of charcoal it creates, before it even becomes incorporated into the fossil record. In this study we have used state-of-the-art calorimetry to experimentally produce charcoal from twenty species that represent a range of surface fuels and growth habits, as a preliminary step towards assessing whether different fuel types (and plant organs) are equally likely to remain as charcoal post-fire. We observe that charcoal production appears to be species specific, and is related to the intrinsic physical and chemical properties of a given fuel. Our observations therefore suggest that some taxa are likely to be overrepresented in fossil charcoal assemblages(i.e. needle-shed conifers, tree ferns) and others poorly represented, or not preserved at all (i.e. broad shoot-shed conifers, weedy angiosperms, shrub angiosperms, some ferns). Our study highlights the complexity of charcoal production in modern fuels and we consider what a bias in charcoal production may mean for our understanding of palaeowildfires.
Hudspith et al_Table1
Table 1. Summary of all taxa tested under ambient atmospheric oxygen conditions (21 vol. % pO2). Calorimetry test information along with an image analysis determined %charcoal left in the remaining ash/char residue post-burn are presented. Species are grouped according to growth habit.
Hudspith et al Table 2
Table 2. Summary of the fifteen species tested under superambient atmospheric oxygen conditions (26 vol. % pO2). Calorimetry test information along with an image analysis determined %charcoal left in the remaining ash/char residue post-burn are presented. Species are grouped according to growth habit.
Figure 1. Podocarpus salignus dead foliage ash/char (Fig. 2E) illustrating the stages of image processing used to determine charcoal percentages. (A) Histogram values obtained for all pixel values in the 8 bit greyscale photograph. (B) Image manually thresholded to a greyscale value of 50 to highlight the charcoal in the image. (C) Default threshold applied to the whole image to separate the background from the ash/char sample and to derive a maximum ash greyscale value.