Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ancient High-Altitude Trees Grow Faster as Temperatures Rise

17.11.2009
Increasing temperatures at high altitudes are fueling the post-1950 growth spurt seen in bristlecone pines, the world's oldest trees, according to new research.
Pines close to treeline have wider annual growth rings for the period from
1951 to 2000 than for the previous 3,700 years, reports a University of Arizona-led research team. Regional temperatures have increased, particularly at high elevations, during the same 50-year time period.

"We're showing this increased growth rate at treeline in a number of locations," said Matthew W. Salzer, a research associate at UA's Laboratory of Tree-Ring Research. "It's unique in several millennia, and it's related specifically to treeline."

Bristlecone pines live for thousands of years on dry, windswept, high-elevation mountain slopes in the western U.S. The scientists collected and analyzed tree rings from Great Basin bristlecone pines located in three mountain ranges in eastern California and Nevada that are separated by hundreds of miles.

Only trees growing within about 500 feet (150 meters) of treeline showed the surge in growth. In general, those trees were at or above about 11,000 feet (3,300 meters) in elevation.

"You can come downslope less than 200 vertical meters and sample the same species of tree, and it won't show the same wide band of growth," Salzer said.

Growth at the pines' upper elevational range is limited by cold temperatures. At the lower elevations, growth of the trees is limited by moisture more than temperature, Salzer said.

Co-author Malcolm K. Hughes said, "Something very unusual is happening at high elevations, and this is one more piece of evidence for that." One other example, he said, was the accelerated melting of small glaciers at high altitudes.

"There is increasingly rapid warming in western North America," said Hughes, a UA Regents' Professor of dendrochronology. "The higher you go, the faster it's warming. We think our finding may be part of that whole phenomenon."

Salzer, Hughes and their co-authors Andrew G. Bunn of Western Washington University in Bellingham and Kurt F. Kipfmueller of the University of Minnesota in Minneapolis will publish their paper, "Recent Unprecedented Tree-ring Growth in Bristlecone Pine at the Highest Elevations and Possible Causes," in this week's Early Online edition of the Proceedings of the National Academy of Sciences. The National Science Foundation funded the research.

Individual Great Basin bristlecone pines, Pinus longaeva, are the longest-living organisms known. The trees live at an elevation range of approximately 8,200 to 11,400 feet (about 2,500 to 3,500 meters). The oldest living bristlecone, almost 5,000 years old, is in California's White Mountains.

The trees' longevity coupled with the excellent preservation of trunks from even older dead trees has allowed some scientists to reconstruct regional climate 8,000 years into the past using tree-ring records from bristlecone pines.

The recent rapid growth of three species of pines at elevations close to treeline had been noticed more than 25 years ago by previous researchers from UA's Laboratory of Tree-Ring Research. The sudden growth surge was puzzling in trees hundreds to thousands of years old, well past adolescence.

"It means there has been some environmental change that affected the trees'
ability to make wood," Salzer said. "The place they were living wasn't as limiting to their growth anymore."

Salzer and his colleagues wanted to study trees whose growth was strongly affected by temperature.

"Where do you go to look for trees where ring width is related to temperature? You look for trees in high mountain ranges, where the mountain continues up and the trees don't follow," Salzer said. "As you go up, the main thing that's changing in these places is temperature."

He and his colleagues chose to extend the previous research efforts. The scientists used the previous researchers' data and also took new bristlecone pine cores to increase the number of samples available for analysis.

The team analyzed the average and median width of tree rings for 50-year blocks of time, starting with the latter half of the 20th century, the years

1951 to 2000, and going backward in time to 2650 B.C. The analysis spans more than 4,600 years.

To see how the annual growth rings changed with temperature, the team used a new method of mapping climate data called PRISM that was unavailable to researchers 25 years ago.

PRISM combines weather records and knowledge of how topography affects weather and climate to provide state-of-the-art climate information going back 100 years for specific locations. PRISM stands for "Parameter-elevation Regressions on Independent Slopes Model."

The tree-ring researchers found that the chronological timing of the wider tree rings correlates with increasing temperatures from the PRISM climate map.

Hughes said that increasing temperatures high in the mountains could have significant effects elsewhere. In many areas of the western U.S., mountains are a key source of water for farms and urban areas at lower elevations.

"If the snow melts earlier, the mountains won't be able to hold onto water for as long," Hughes said. "They won't be as effective as water towers for us."

The same pattern of high-elevation growth increases has also been observed in Rocky Mountain bristlecone pines, including ones in Arizona's San Francisco Peaks, Salzer said. He plans to expand the research to investigate high-altitude trees at additional locations.

Contact information:

Matthew Salzer, 520-621-2946.
msalzer@ltrr.arizona.edu
Malcolm Hughes, 520-621-6470,
mhughes@ltrr.arizona.edu
Related Web sites:
Matthew Salzer
http://www.ltrr.arizona.edu/~msalzer/
Malcolm Hughes
http://www.ltrr.arizona.edu/people/8
PRISM
http://www.prism.oregonstate.edu/

Mari N. Jensen | University of Arizona
Further information:
http://www.arizona.edu
http://www.nsf.gov/news/newsmedia/treerings/index.html

More articles from Agricultural and Forestry Science:

nachricht Six-legged livestock -- sustainable food production
11.05.2017 | Faculty of Science - University of Copenhagen

nachricht Elephant Herpes: Super-Shedders Endanger Young Animals
04.05.2017 | Universität Zürich

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: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>