Warming Arctic Could Lead to More Tundra Fires Says New Study
18.11.2010 - Land & Geology, Flora & Fauna, Arctic
The Anaktuvuk River Fire, which burned over 1,000 km² of Alaskan tundra in September 2007, has become the subject of a new study recently published in the Journal of Geophysical Research-Biogeosciences. The new analysis of sediment cores retrieved from the burned area revealed that the destructive event was the most intense to have occurred on the site over the course of the last 5,000 years.
Trying to determine whether the event was a consequence of climate change or a natural event, University of Illinois plant biology professor Feng Sheng Hu chartered a helicopter to the area in 2008 and collected various sediment cores from two affected lakes. Together with his team, he then analyzed the distribution of charcoal particles in the cores and used established techniques to determine the approximate ages of different sediment layers. This allowed them to determine that no fire of such intensity occurred in the region during the last 5,000 years.
The team then analyzed 60 years of fire, temperature and precipitation records from the Alaskan tundra, the researchers developed a model linking the tundra area burned in Alaska each year to the mean temperature and precipitation in the Arctic summer. The pattern that emerged showed a “dramatic, nonlinear relationship between climate conditions and tundra fires,” according to Professor Hu, including what might be considered “a tipping point”. “Once the temperature rises above a mean threshold of 10°C in the June-through-September time period, the tundra is just going to burn more frequently," said Hu.