Earth Science News  





. Warming Climate May Cause Arctic Tundra To Burn

The world's high latitude tundra and boreal forest ecosystems contain roughly 30 percent of the planet's total soil carbon. Currently, much of the carbon is locked in permafrost. But a warming climate could cause the permafrost to melt and release its carbon stores into the atmosphere where it would contribute to the greenhouse effect.
by Staff Writers
Washington DC (SPX) Mar 05, 2008
Research from ancient sediment cores indicates that a warming climate could make the world's arctic tundra far more susceptible to fires than previously thought. The findings, published this week in the online journal, PLoS ONE, are important given the potential for tundra fires to release organic carbon - which could add significantly to the amount of greenhouse gases already blamed for global warming.

Montana State University post-doctoral researcher Philip Higuera is the lead author on the paper, which summarizes a portion of a four-year study funded by the National Science Foundation.

Higuera and his co-authors examined ancient sediments from four lakes in a remote region of Alaska in and around Gates of the Arctic National Park to determine what kind of vegetation existed in the area after the last ice age, 14,000 to 9,000 years ago.

By looking at fossilized pollen grains in the sediment cores, Higuera and his co-authors determined that after the last ice age, the arctic tundra was very different from what it is now. Instead of being covered with grasses, herbs, and short shrubs, it was covered with vast expanses of tall birch shrubs.

Charcoal preserved in the sediment cores also showed evidence that those shrub expanses burned - frequently.

"This was a surprise," Higuera said. "Modern tundra burns so infrequently that we don't really have a good idea of how often tundra can burn. Best estimates for the most flammable tundra regions are that it burns once every 250-plus years."

The ancient sediment cores showed the shrub tundra burned as frequently as modern boreal forests in Alaska - every 140 years on average, but with some fires spaced only 30 years apart.

Higuera's research is important because other evidence indicates that as the climate has warmed in the past 50 to 100 years, shrubs have expanded across the world's tundra regions.

"There is evidence of increasing shrub biomass in modern tundra ecosystems, and we expect temperatures to continue to increase and overall moisture levels to decrease. Combine these two factors and it suggests a greater potential for fires," Higuera said. "The sediment cores indicate that it's happened before."

The world's high latitude tundra and boreal forest ecosystems contain roughly 30 percent of the planet's total soil carbon. Currently, much of the carbon is locked in permafrost. But a warming climate could cause the permafrost to melt and release its carbon stores into the atmosphere where it would contribute to the greenhouse effect.

"Vegetation change through an increase in shrub biomass and more frequent burning will change a great deal of the carbon cycle in these high latitudes," Higuera said. "We don't fully understand the implications, except that it's reasonable to expect that carbon that was previously locked up could enter the atmosphere."

The paper is the first in a series Higuera expects to publish from his field work. Future papers will examine how climate, vegetation, and fire regimes have interacted over the past 15,000 years in the region.

Community
Email This Article
Comment On This Article

Related Links
Public Library of Science
Beyond the Ice Age




Tempur-Pedic Mattress Comparison

Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News
Greenland's Rising Air Temperatures Drive Ice Loss At Surface And Beyond
Greenbelt MD (SPX) Feb 21, 2008
A new NASA study confirms that the surface temperature of Greenland's massive ice sheet has been rising, stoked by warming air temperatures, and fueling loss of the island's ice at the surface and throughout the mass beneath.

.
Get Our Free Newsletters Via Email
  



  • Outsourcing The Answer For EU Forces, Commander Says
  • Indonesian govt under fire for mud volcano compensation
  • Indonesian city braces for disaster with little more than hope
  • Death toll from China snow storms hits 129: report

  • Will Global Warming Increase Plant Frost Damage
  • Australian drought easing but not over: experts
  • Tokyo bourse says looking at carbon trading
  • Seafloor Cores Show Tight Bond Between Dust And Past Climates

  • Falcon Investigates Pollution From The Dakar Metropolis Into Desert Dust Layers
  • NASA Extends Mission For Ball Aerospace-Built ICESat
  • CIRA Scientist Among Authors Of Book Celebrating 50 Years Of Earth Observations From Space
  • Indonesia To Develop New EO Satellite

  • Outside View: China's energy diplomacy
  • Sudan villagers, environment suffer from oil boom
  • Sierra Club Comes Out In Favor Of The US Natural Gas Industry
  • Key Discovered For Converting Waste To Electricity

  • Bush urges Congress to pass bigger AIDS program for Africa
  • WHO plays down bird flu threat in China after three human deaths
  • Death of woman confirmed bird flu related: China health ministry
  • Yellow fever outbreak reported in Paraguay

  • Can Moths Or Butterflies Remember What They Learned As Caterpillars
  • French biologists sound alarm over imperilled species
  • Study Finds Future Battlegrounds For Conservation Very Different To Those In Past
  • Invasion Of The Cane Toads

  • Greeks shipping firms oppose pollution controls
  • Chinese yellow sand hits Japan, SKorea: officials
  • Gold upstream, poison downstream in Philippines fairy mountain
  • Creation Of A New Material Capable Of Eliminating Pollutants Generated By The Hydrocarbon Industry

  • Genes Hold The Key To How Happy We Are
  • Humans Show Innate Ability To Detect The Snake In The Grass
  • Culture-shaping elite go to TED for mind-bending inspiration
  • Gender Differences In Language Appear Biological

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2007 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement