Tree ring-based reconstruction of the long-term influence of wildfires on permafrost active layer dynamics in Central Siberia

KNORRE, Anastasia A., Alexander V. KIRDYANOV, Anatoly S. PROKUSHKIN, Paul J. KRUSIC and Ulf BÜNTGEN. Tree ring-based reconstruction of the long-term influence of wildfires on permafrost active layer dynamics in Central Siberia. Science of the Total Environment. Amsterdam: Elsevier Science, 2019, vol. 652, FEB 20 2019, p. 314-319. ISSN 0048-9697. Available from: https://dx.doi.org/10.1016/j.scitotenv.2018.10.124.

Basic information

• Original name: Tree ring-based reconstruction of the long-term influence of wildfires on permafrost active layer dynamics in Central Siberia
• Authors: KNORRE, Anastasia A., Alexander V. KIRDYANOV (guarantor), Anatoly S. PROKUSHKIN, Paul J. KRUSIC and Ulf BÜNTGEN (276 Germany, belonging to the institution).
• Edition: Science of the Total Environment, Amsterdam, Elsevier Science, 2019, 0048-9697.

Other information

• Original language: English
• Type of outcome: Article in a journal
• Field of Study: 10511 Environmental sciences
• Country of publisher: Netherlands
• Confidentiality degree: is not subject to a state or trade secret
• WWW: URL
• Impact factor: Impact factor: 6.551
• RIV identification code: RIV/00216224:14310/19:00113510
• Organization unit: Faculty of Science
• Doi: http://dx.doi.org/10.1016/j.scitotenv.2018.10.124
• UT WoS: 000454418500029
• Keywords in English: Boreal forest; Ecological interaction; Ecosystem response; Seasonally thawing soil layer; Sphagnum; Larix gmelinii
• Tags: rivok
• Tags: International impact, Reviewed

Abstract

Although it has been recognized that rising temperatures and shifts in the hydrological cycle affect the depth of the seasonally thawing upper permafrost stratum, it remains unclear to what extent the frequency and intensity of wildfires, and subsequent changes in vegetation cover, influence the soil active layer on different spatiotemporal scales. Here, we use ring width measurements of the subterranean stem part of 15 larch trees from a Sphagnum bog site in Central Siberia to reconstruct long-term changes in the thickness of the active layer since the last wildfire occurred in 1899. Our approach reveals a three-step feedback loop between above- and belowground ecosystem components. After all vegetation is burned, direct atmospheric heat penetration over the first similar to 20 years caused thawing of the upper permafrost stratum. The slow recovery of the insulating ground vegetation reverses the process and initiates a gradual decrease of the active layer thickness. Due to the continuous spreading and thickening of the peat layer during the last decades, the upper permafrost horizon has increased by 0.52 cm/year. This study demonstrates the strength of annually resolved and absolutely dated tree-ring series to reconstruct the effects of historical wildfires on the functioning and productivity of boreal forest ecosystems at multi-decadal to centennial time-scale. In so doing, we show how complex interactions of above- and belowground components translate into successive changes in the active permafrost stratum. Our results are particularly relevant for improving long-term estimates of the global carbon cycle that strongly depends on the source and sink behavior of the boreal forest zone.