Massive Tundra Fire
Two years ago a Cape Cod-sized section of tundra burned in a three-month wildfire. It was the biggest tundra fire on record in Alaska (tundra is generally too moist to burn) and provided an excellent research site for the scientists here studying climate change and the future of the arctic.
They're looking at the fire's impact on carbon release, vegetation and the landscape. They estimate that the amount of carbon burned during the fire is equal to 10% of Boston's annual emissions. And the more severely burned the land, the less carbon it's absorbing from the atmosphere and the higher the soil temperature is long after the fire burned out. Warmer soil leads to warmer air which leads to increased lightening when that warm air hits the cold mountain air, which means more fires. (Lightening strikes on the North Slope have risen dramatically in the past 10 years, and 2007 saw roughly 40% more than any year in the past.)
Burning the top layer of the tundra released nutrients that were frozen in the soil, which can give different species a competitive advantage in finding food, thus changing the makeup of tundra vegetation. This, in turn, can alter the tundra's temperature and carbon absorption.
We visited the fire site last week where the cotton grass was in full bloom. The white flowers against the black earth made it look other worldly. And it may be a sign of ecosystem change. The cotton grass near camp isn't anywhere near as brilliant. Researchers think that the nutrients released in the soil may be allowing the plants there to bloom more heavily than in other spots.
Another alarming change is an apparent increase in thermokarst, which occur where ice in the permafrost melts and the ground collapses in on itself like a soufflé. Thermokarsts along lakes and streams dump nutrients into the water, which changes those ecosystems.
All of these changes initiate positive feedback loops that could dramatically alter the arctic. And its unclear if people can do anything to stop these natural processes once they've been set in motion. As one researcher put it, "We can't make a treaty to stop thermokarst and fires."
They're looking at the fire's impact on carbon release, vegetation and the landscape. They estimate that the amount of carbon burned during the fire is equal to 10% of Boston's annual emissions. And the more severely burned the land, the less carbon it's absorbing from the atmosphere and the higher the soil temperature is long after the fire burned out. Warmer soil leads to warmer air which leads to increased lightening when that warm air hits the cold mountain air, which means more fires. (Lightening strikes on the North Slope have risen dramatically in the past 10 years, and 2007 saw roughly 40% more than any year in the past.)
Burning the top layer of the tundra released nutrients that were frozen in the soil, which can give different species a competitive advantage in finding food, thus changing the makeup of tundra vegetation. This, in turn, can alter the tundra's temperature and carbon absorption.
We visited the fire site last week where the cotton grass was in full bloom. The white flowers against the black earth made it look other worldly. And it may be a sign of ecosystem change. The cotton grass near camp isn't anywhere near as brilliant. Researchers think that the nutrients released in the soil may be allowing the plants there to bloom more heavily than in other spots.
Another alarming change is an apparent increase in thermokarst, which occur where ice in the permafrost melts and the ground collapses in on itself like a soufflé. Thermokarsts along lakes and streams dump nutrients into the water, which changes those ecosystems.
All of these changes initiate positive feedback loops that could dramatically alter the arctic. And its unclear if people can do anything to stop these natural processes once they've been set in motion. As one researcher put it, "We can't make a treaty to stop thermokarst and fires."
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