Wildfires Turning Alaskan Forests into Carbon Source
11.02.2011 - Atmosphere & Space, Land & Geology, Flora & Fauna, Arctic
A joint Canadian-American study published in the journal Nature reported that wildfires in Alaska – which researchers believe are a consequence of climate change – are turning spruce forests into carbon generators. Wildfires release carbon dioxide into the atmosphere, which further contributes to climate warming. The extent of the impact the wildfires have depends on their frequency and severity.
The greatest amount of carbon in forests is stored in the layers of moss, peat and fallen leaves that cover the ground, which are the most likely to burn in wildfires. The loss of this base layer affects natural processes, such as regulation of soil climate, maintenance of permafrost and the types of tree that grows back after a wildfire.
Collecting data on the depth of ground-layer combustion at 178 sites, the scientists found that when larger areas burned, the severity of the damage remained high throughout the fire season and resulted in higher carbon emissions. They determined that the annual carbon losses related to forest fires between 2000 and 2009 were more than twice the carbon lost during each of the previous five decades.
Over the coming decades, the annual area burned in Alaska is expected to increase by 200 to 300%.
