Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Trees appear to respond slower to climate change than previously thought

03.08.2006
Genetic analysis of living spruce trees provides strong evidence for the presence of a tree refuge in Alaska during the height of the last glacial period (17,000 to 25,000 years ago), and suggests that trees cannot migrate in response to climate change as quickly as some scientists thought.

The DNA survey and analysis, led by researchers at the University of Illinois at Urbana-Champaign, will be posted online this week ahead of regular publication by the Proceedings of the National Academy of Sciences.

"White spruce (Picea glauca) is a dominant species in the boreal forests of North America," said Lynn L. Anderson, lead author and doctoral student. "In the face of global warming, we need to study how plant and animal populations have responded to climate change in the past, to better predict what will happen in the future."

In their study, the researchers analyzed chloroplast DNA from 24 spruce forests in Alaska and Canada. Because chloroplast DNA contains genes inherited from only one parent, there is no confusing genetic recombination to take into account.

"We found a significant pattern in the geographic distribution of the chloroplast DNA haplotypes (groups of individuals with similar sequences of base pairs of genetic material) that differentiates into two regions," Anderson said.

The chloroplast DNA, the researchers write, "offers compelling evidence that white spruce survived the last glacial maximum and probably some of the previous glacial episodes in Alaska. This survival must have been facilitated by the existence of favorable microhabitats … and by adaptations of these trees to harsh climate."

The DNA data help resolve an old controversy over the manner in which trees had migrated in response to past climate change, said Feng Sheng Hu, an ecologist at Illinois and corresponding author of the paper.

"One view is that trees were restricted to areas south of the continental ice sheets covering North America, and then migrated extremely rapidly as the climate grew warmer," Hu said. "The other view is that there was a refuge in the ice-free areas north of the ice sheets, and spruce trees expanded within those areas as the climate warmed. It now seems clear that a glacial refuge existed, and the trees advanced from at least two directions."

Based on the data, it also appears likely that the migration rate was lower than previously thought.

"Our results suggest that estimated rates of tree migration from fossil pollen records are too high and that the ability of trees to keep pace with global warming is more limited than previously thought," said Hu, who has studied plant responses to climate change for 15 years. "Additional analysis of fossil pollen in sediments, as well as DNA data from living trees, could help pin down the actual rate of tree movement over time."

The researchers' findings also illustrate the great resilience of white spruce – and perhaps other tree species – to climate change, and have important implications for the future.

For example, isolated populations of trees might persist in locally suitable habitats for long periods after regional climatic conditions have become unfavorable as a result of rapid global warming. This resilience might reduce the probability of species extinction and allow time for efforts at biodiversity conservation.

Or maybe not.

"Our study looked at the past, before humans had made any significant impact on climate," said Hu. "In the future, both human and natural disturbances will likely interact with climate change to reduce resilience and trigger larger ecological shifts."

The study "illustrates the power of using genetic techniques to answer paleoecological questions relevant to global change," said co-author Ken N. Paige, who has studied the genetic structure and dynamics of plant and animal populations for more than 20 years. "It's likely that more new insights can be gained by studying other plant and animal species with this approach."

James E. Kloeppel | EurekAlert!
Further information:
http://www.uiuc.edu

More articles from Ecology, The Environment and Conservation:

nachricht Scientists team up on study to save endangered African penguins
16.11.2017 | Florida Atlantic University

nachricht Climate change: Urban trees are growing faster worldwide
13.11.2017 | Technische Universität München

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>