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Fire frequency and intensity associated with functional traits of dominant forest type in the Balkans during the Holocene

  • Angelica FeurdeanEmail author
  • Spassimir Tonkov
  • Mirjam Pfeiffer
  • Andrei Panait
  • Dan Warren
  • Boris Vannière
  • Elena Marinova
Original Paper

Abstract

Disturbances by fire are among the most important processes that shape forest dynamics and diversity. However, the long-term variability of fire disturbance regimes in many European forests and specifically in the mountains of the Balkan Peninsula is not well understood. Here, we present the first Holocene record of fire regimes based on macrocharcoal morphologies in combination with pollen-based reconstruction of forest dynamics and fire-related strategies of prevailing mountain forests in the Rila Mountains, Bulgaria. While biomass burning followed the main trends in climate, the frequency and intensity of fire were strongly linked to fire-related coping strategies of dominant tree taxa (resisters, avoiders or invaders). Frequent fires of low intensity between 12,000 and 9000 cal year BP were concurrent with the dominance of invaders (Betula, herbs, ferns). Intermittent occurrence of low- and high-intensity surface and crown fires with longer return intervals between 9000 and 4000 cal year BP was associated with codominance of resister (Pinus sylvestris, Pinus peuce, Pinus mugo) and avoider (Abies alba and Picea abies) forest types, whereas a lengthening of the fire return interval over the past 4000 years was linked to increased abundance of P. abies. As a rising number of fire episodes may drive land cover towards more fire-adapted plant communities and towards less intense fire events, we expect increased dominance of invaders (resprouters that rapidly reach maturity stage) as well as resisters (properties protecting from fire damage) under future warmer and drier climate. This study also shows the potential of combining charcoal morphologies with pollen records to track variability in fire intensity and plant functional attributes over long timescales that are also relevant to forest management stakeholders.

Keywords

Fire Post-fire regeneration Invaders Resisters Avoiders Vegetation Pollen Charcoal 

Notes

Acknowledgements

This work was supported by the German Research Foundation [FE-1096/4-1]. It also received support from CNCS—UEFISCDI [PN-III-P4-ID-PCE-2016-0711]. We thank G. Wolff for his assistance during the filedwork.

Supplementary material

10342_2019_1223_MOESM1_ESM.docx (194 kb)
Online Resource 1. The Chronology of the Vapsko-2 sediment sequence (DOCX 194 kb)
10342_2019_1223_MOESM2_ESM.docx (157 kb)
Online Resource 2. Change-point analysis developed to determine statistically significant changes in CHAR over time (DOCX 156 kb)
10342_2019_1223_MOESM3_ESM.tif (923 kb)
Online Resource 3a. Pollen diagram of selected tree and shrubs (TIFF 923 kb)
10342_2019_1223_MOESM4_ESM.tif (1.2 mb)
Online Resource 3b. Pollen diagram of selected herbs and ferns (TIFF 1235 kb)
10342_2019_1223_MOESM5_ESM.docx (55 kb)
Online Resource 4. Fossil stomata record in Vapsko-2 (in absolute number) (DOCX 54 kb)

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Authors and Affiliations

  1. 1.Senckenberg Biodiversity and Climate Research Centre (BiK-F)Frankfurt am MainGermany
  2. 2.Department of GeologyBabeş-Bolyai UniversityCluj-NapocaRomania
  3. 3.Department of Physical GeographyGoethe UniversityFrankfurt am MainGermany
  4. 4.Laboratory of Palynology, Faculty of BiologySofia University St. Kliment OhridskiSofiaBulgaria
  5. 5.CNRS Chrono-Environnement, UMR 6249 and MSHE USR 3124Université Bourgogne Franche-ComtéBesançonFrance
  6. 6.State Office for Cultural Heritage Baden-Württemberg, Referat 84.1/Laboratory for ArchaeobotanyGeienhofen-HemmenhofenGermany

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