Do small landforms have large effects? A review on the legacies of pre-industrial charcoal burning

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Thomas Raab - , Brandenburg University of Technology (Author)
  • Alexandra Raab - , Brandenburg University of Technology (Author)
  • Alexander Bonhage - , Brandenburg University of Technology (Author)
  • Anna Schneider - , Brandenburg University of Technology (Author)
  • Florian Hirsch - , Brandenburg University of Technology (Author)
  • Klaus Birkhofer - , Brandenburg University of Technology (Author)
  • Patrick Drohan - , Pennsylvania State University (Author)
  • Martin Wilmking - , University of Greifswald (Author)
  • Jürgen Kreyling - , University of Greifswald (Author)
  • Ireneusz Malik - , Silesian University in Opava (Author)
  • Malgorzata Wistuba - , Silesian University in Opava (Author)
  • Ernst van der Maaten - , Chair of Forest Growth and Woody Biomass Production (Author)
  • Marieke van der Maaten-Theunissen - , Chair of Forest Growth and Woody Biomass Production (Author)
  • Tim Urich - , University of Greifswald (Author)

Abstract

Relict charcoal hearths (RCHs) are small, anthropogenic landforms resulting from past charcoal burning and reaching significant land coverage in pre-industrial mining areas. We review three coupled legacies linked by RCH development: (i) a landscape-scale geomorphic effect, (ii) a unique soil fingerprint, and (iii) an evolving novel ecosystem. The history and technique of charcoal production are described to clarify legacy effects. Applying a recently presented morpho-genetic catalogue is useful for classified mapping of RCH findings. The RCH numbers and calculated RCH densities per study region vary greatly and impose uncertainties due to insufficient methods causing over- or underestimations. Areas with high RCH densities between 50 and 500 RCH/km2 seem reasonable. Machine learning-based remote sensing techniques are promising approaches with which to better assess the full scale of charcoal burning legacies. RCH soil properties feature dark charcoal-rich technogenic substrate layers classified as Auh horizons according to the World Reference Base with significantly increased C contents. These Auh horizons can also exhibit specific physical and chemical properties, such as relatively low bulk density, high porosity, high plant available water content, low thermal conductivity and differences in cation exchange capacity or nutrient status. However, relevant studies are rare, and thus, the effects may differ by study region. Regarding vegetation, there seem to be four main effects: changes in forest structure, species composition, recruitment pattern and productivity. The number of studies on this issue is, however, also very limited. Even fewer studies have examined the soil fauna in RCHs; thus, the reported effects cannot be used to draw general conclusions. Notably, RCH research has made considerable progress in the last five years, especially in the Light Detection and Ranging-based mapping of these small landforms and identifi- cation of RCH-specific soil properties, but ecological legacies are not well understood; thus, more interdisci- plinary and integrative studies are needed.

Details

Original languageEnglish
Article number108332
JournalGeomorphology
Volume413
Publication statusPublished - 15 Sept 2022
Peer-reviewedYes

External IDs

Scopus 85132418560
ORCID /0000-0002-5218-6682/work/151438954

Keywords

Sustainable Development Goals