Earth's Biggest Tree Rings Tell Fiery Tales

The tree rings of 52 fallen giant sequoias, Earth's biggest trees, have revealed a 3,000-year-old history of droughts and fires. Hemera/ThinkStock

From Discovery News:

Fifty-two giant fallen giant sequoias reveal a 3,000-year-old history of fire and drought after giant chainsaws expose their rings.

Using huge chainsaws and strong backs, the largest trees in the world are finally giving up their 3,000-year record of fires and droughts. No trees, however, were harmed in the making of this fire history.

"We only used dead trees," emphasized tree ring researcher Thomas Swetnam of the University of Arizona. Swetnam led the study that was reported in a recent issue of the journal Fire Ecology. "We spent multiple years collecting the wood and hauling it back to Tucson."

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Global Warming: 'Cooling' Forests Can Heat Too

Pine forest. The simple formula we've learned in recent years -- forests remove the greenhouse gas CO2 from the atmosphere; therefore forests prevent global warming -- may not be quite as simple as we thought. Forests can directly absorb and retain heat, and, in at least one type of forest, these effects may be strong enough to cancel out a good part of the benefit in lowered CO2. (Credit: iStockphoto/Jeremy Sterk)

From Science Daily:

ScienceDaily (Jan. 25, 2010) — The simple formula we've learned in recent years -- forests remove the greenhouse gas CO2 from the atmosphere; therefore forests prevent global warming -- may not be quite as simple as we thought. Forests can directly absorb and retain heat, and, in at least one type of forest, these effects may be strong enough to cancel out a good part of the benefit in lowered CO2. This is a conclusion of a paper that will be published on January 22, in Science by scientists in the Weizmann Institute's Faculty of Chemistry.

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Scientists: Northern Forests Need Saving, Too

From Live Science:

When fire destroys forests, or when discarded wood products are burned at the dump, carbon dioxide (CO2) escapes into the air. Hence, in part, the uproar denouncing the slash-and-burn destruction of tropical jungles. But let’s not overlook another great woodland biome: the boreal forest.

That’s the plea voiced in a recent opinion paper by Corey J.A. Bradshaw of the University of Adelaide in Australia and two colleagues. They point out that far northern forests represent a third of all remaining woodlands and 30 percent of all terrestrially stored carbon on Earth. Those vast coniferous tracts covering much of Alaska, Canada, Scandinavia, and Russia are still relatively unscathed, but they face increasing threats.

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Greenhouse Gas Carbon Dioxide Ramps Up Aspen Growth

Stand of quaking aspen. (Credit: iStockphoto/Doug Sims)

From Science Daily:

ScienceDaily (Dec. 4, 2009) — The rising level of atmospheric carbon dioxide may be fueling more than climate change. It could also be making some trees grow like crazy.

That is the finding of a new study of natural stands of quaking aspen, one of North America's most important and widespread deciduous trees. The study, by scientists from the University of Wisconsin-Madison and the University of Minnesota at Morris (UMM) and published December 4 in the journal Global Change Biology, shows that elevated levels of atmospheric carbon dioxide during the past 50 years have boosted aspen growth rates by an astonishing 50 percent.

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As Farmland Grows, The Trees Fight Back

A ripening barley field in Bourton on the Water in Gloucestershire, Britain
Tim Graham / Getty

From Time Magazine:

Farms vs. forests — that's the usual dynamic in tropical countries, where the growth of agriculture often comes at the expense of trees. In nations like Brazil and Indonesia — where deforestation is behind the vast majority of carbon emissions — rain forests are not just cut down for logging but also burned to make room for new farms and pastureland. As more people need more food — and biofuels as well — there's a risk that we could see many of our remaining virgin rain forests wiped out completely.

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World's Last Great Forest Under Threat: New Study

Canadian evergreen forest. (Credit: iStockphoto/Stacey Newman)

From Science Daily:

ScienceDaily (Aug. 25, 2009) — The world's last remaining "pristine" forest -- the boreal forest across large stretches of Russia, Canada and other northern countries -- is under increasing threat, a team of international researchers has found.

The researchers from the University of Adelaide in Australia, Memorial University of Newfoundland in Canada and the National University of Singapore have called for the urgent preservation of existing boreal forests in order to secure biodiversity and prevent the loss of this major global carbon sink.

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