Temperature-controlled tundra fire severity and frequency during the last millennium in the Yukon-Kuskokwim Delta, Alaska

Sae-Lim, Jarunetr, Russell, James, Vachula, Richard, Holmes, Robert, Mann, Paul, Schade, John and Natali, Susan (2019) Temperature-controlled tundra fire severity and frequency during the last millennium in the Yukon-Kuskokwim Delta, Alaska. The Holocene, 29 (7). pp. 1223-1233. ISSN 0959-6836

_system_appendPDF_proof_hi.pdf - Accepted Version

Download (3MB) | Preview
Official URL: https://doi.org/10.1177/0959683619838036


Wildfire is an important disturbance to Arctic tundra ecosystems. In the coming decades, tundra fire frequency, intensity, and extent are projected to increase because of anthropogenic climate change. To more accurately predict the effects of climate change on tundra fire regimes, it is critical to have detailed knowledge of the natural frequency and extent of past wildfires and how they responded to past climate variability. We present analyses of fire frequency and temperature from a lake sediment core from the Yukon-Kuskokwim (YK) Delta. Our ca. 1000 macroscopic charcoal record shows more frequent but possibly less severe tundra fires during the first half of the last millennium, whereas less frequent, possibly more severe fires characterize the latter half. Our temperature reconstruction, based on distributional changes of branched glycerol dialkyl glycerol tetraethers (brGDGTs), shows slightly warmer conditions from ca. AD 1000 to 1500, and cooler conditions thereafter (ca. AD 1500 to 2000), suggesting that fire frequency increases when climate is relatively warmer in this region. When wildfires occur more frequently, fire severity may decrease because of limited biomass (fuel source) accumulating between fires. The data suggest that tundra ecosystems are highly sensitive to climate change, and that a warmer climate, which is predicted to develop in the near future, will result in more frequent tundra wildfires.

Item Type: Article
Uncontrolled Keywords: Alaska, Arctic, charcoal, glycerol dialkyl glycerol tetraethers (GDGTs), late-Holocene, paleoclimate, paleofire
Subjects: F800 Physical and Terrestrial Geographical and Environmental Sciences
Department: Faculties > Engineering and Environment > Geography and Environmental Sciences
Depositing User: Becky Skoyles
Date Deposited: 29 Mar 2019 09:36
Last Modified: 01 Aug 2021 11:21
URI: http://nrl.northumbria.ac.uk/id/eprint/38626

Actions (login required)

View Item View Item


Downloads per month over past year

View more statistics