Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dire Drought Ahead, May Lead to Massive Tree Death

17.10.2012
Evidence uncovered by a University of Tennessee, Knoxville, geography professor suggests recent droughts could be the new normal. This is especially bad news for our nation's forests.

For most, to find evidence that recent years' droughts have been record-breaking, they need not look past the withering garden or lawn. For Henri Grissino-Mayer he looks at the rings of trees over the past one thousand years. He can tell you that this drought is one of the worst in the last 600 years in America's Southwest and predicts worst are still to come.

Grissino-Mayer collaborated with a team of scientists led by Park Williams of Los Alamos National Laboratory and others from the U.S. Geological Survey, University of Arizona and Columbia University to evaluate how drought affects productivity and survival in conifer trees in the Southwestern U.S. Their findings are published this month in Nature Climate Change.

Tree rings act as time capsules for analyzing climate conditions because they grow more slowly in periods of drought and the size of rings they produce vary accordingly. Widely spaced rings indicate wetter seasons and narrow rings indicate drier seasons.

"Using a comprehensive tree-ring data set from A.D. 1000 to 2007, we found that the U.S. has suffered several 'mega-droughts' in the last 1,000 years in the Southwest," said Grissino-Mayer. "But the most recent drought that began in the late 1990s lasted through the following decade and could become one of the worst, if not the worst, in history."

The researchers created a tree-ring-based index that catalogs the drought stress on forests which resolves the contributions of vapor-pressure deficit—the difference between the moisture in the air and how much the air can hold—and precipitation. They linked this information to disturbances that cause changes in forests, such as bark-beetle outbreaks, mortality and wildfires and compared these data with their model projections.

"Looking forward to 2050, our climate-forest stress model suggests we will see worse drought and increased tree mortality than we've seen in the past 1,000 years," Grissino-Mayer said. "This drought will be exacerbated by increasing temperatures globally, foreshadowing major changes in the structure and species composition of forests worldwide."

Increasing temperatures impact the water balance because they exponentially influence how much water evaporates into the atmosphere. More water in the air means less water in the ground. Trees need that water to survive, especially in water-limited areas like the American Southwest.

"We have nothing comparable in the past to today's environment and certainly tomorrow's environment," Grissino-Mayer said. "With increasing drought stress, our forests of tomorrow will hardly resemble our forests of yesterday."

Grissino-Mayer suggests forest management practices will need to adjust to the changes, noting the increased danger for wildfires even in East Tennessee's Great Smoky Mountains.

Whitney Heins | Newswise Science News
Further information:
http://www.utk.edu

More articles from Agricultural and Forestry Science:

nachricht Researchers discover natural product that could lead to new class of commercial herbicide
16.07.2018 | UCLA Samueli School of Engineering

nachricht Advance warning system via cell phone app: Avoiding extreme weather damage in agriculture
12.07.2018 | Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e.V.

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Microscopic trampoline may help create networks of quantum computers

17.07.2018 | Information Technology

In borophene, boundaries are no barrier

17.07.2018 | Materials Sciences

The role of Sodium for the Enhancement of Solar Cells

17.07.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>