High-resolution records detect human-caused changes to the boreal forest wildfire regime in interior Alaska

The Holocene
By: , and 

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Abstract

Stand-replacing wildfires are a keystone disturbance in the boreal forest, and they are becoming more common as the climate warms. Paleo-fire archives from the wildland–urban interface can quantify the prehistoric fire regime and assess how both human land-use and climate change impact ecosystem dynamics. Here, we use a combination of a sedimentary charcoal record preserved in varved lake sediments (annually layered) and fire scars in living trees to document changes in local fire return intervals (FRIs) and regional fire activity over the last 500 years. Ace Lake is within the boreal forest, located near the town of Fairbanks in interior Alaska, which was settled by gold miners in AD 1902. In the 400 years before settlement, fires occurred near the lake on average every 58 years. After settlement, fires became much more frequent (average every 18  years), and background charcoal flux rates rose to four times their preindustrial levels, indicating a region-wide increase in burning. Despite this surge in burning, the preindustrial boreal forest ecosystem and permafrost in the watershed have remained intact. Although fire suppression has reduced charcoal influx since the 1950s, an aging fuel load experiencing increasingly warm summers may pose management problems for this and other boreal sites that have similar land-use and fire histories. The large human-caused fire events that we identify can be used to test how increasingly common megafires may alter ecosystem dynamics in the future.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title High-resolution records detect human-caused changes to the boreal forest wildfire regime in interior Alaska
Series title The Holocene
DOI 10.1177/0959683616632893
Volume 26
Issue 7
Year Published 2016
Language English
Publisher SAGE Publications
Contributing office(s) Alaska Science Center Geography
Description 11 p.
First page 1064
Last page 1074
Country United States
State Alaska
Other Geospatial Ace Lake
Online Only (Y/N) N
Additional Online Files (Y/N) N