GAINESVILLE, Fla. --- Although vegetation growth in the Arctic is boosted by global warming, it's not enough to offset the carbon released by the thawing of the permafrost beneath the surface, University of Florida researchers have found in the first experiment in the Arctic environment to simulate thawing of permafrost in a warming world.
Twice as much carbon is frozen in Arctic permafrost as exists in the atmosphere today, and what happens to it as it thaws releasing greenhouse gases that fuel climate change is a key question, said professor Ted Schuur, who heads the Permafrost Carbon Network and the Ecosystem Dynamics Research Laboratory in the UF department of biology.
Schuur, postdoctoral researcher Susan Natali and their team report the results of the three-year study in the journal Ecology, released this week online.
"The plants like it when they're warmer, so their growth is increasing, and if you just watch the tundra in the summertime and you look at the balance between what the plants are doing and what the soil is doing, the plants actually offset everything that happens in the soil. They're growing faster, getting bigger and taking carbon out of the air," Schuur said. "From the perspective of climate change, that's a good thing, tundra vegetation is making up for any carbon you're losing from the soil."
The hitch? The Arctic's short summers do not make up for the long winters.
Researchers are interested in the permafrost of the polar regions because these soils permanently frozen at great depths and for tens of thousands of years are vulnerable to global warming.
"We continued to measure emissions in the winter, and what happens is the plants are shutting down, they're dormant, but the microbes continue to eat the soil, and it turns out that they release enough carbon during the winter to offset everything the plants gained in the summer, and possibly even more," Schuur said.<
|Contact: Ted Schuur|
University of Florida