Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Duke study disputes idea that trees can ’relocate’quickly in response to climate change

02.08.2004


In a study with implications for how North American trees might respond to a changing climate, molecular information collected by Duke University researchers refutes a widely accepted theory that many of the continent’s tree species migrated rapidly from the deep South as glaciers retreated at the end of the last Ice Age.



"When you put the molecular data together with other lines of evidence, it suggests that maybe they didn’t move as fast as we previously thought," said James Clark, H.L. Blomquist Professor of Biology at Duke’s Nicholas School of the Environment and Earth Sciences.

"Maybe the species that are growing far to the north today weren’t far to the south during the last glacial," Clark said in an interview. "Maybe, in fact, they were further north near the edge of the ice and therefore didn’t have to migrate as fast."


A talk on the research by Clark, Clark’s research associate Jason McLachlan and associate professor of biology Paul Manos will be presented at a session beginning at 1:30 p.m. on Wednesday, Aug. 4, in Meeting Room D136 of the Oregon Convention Center during the Ecological Society of America’s 2004 annual meeting in Portland.

In an interview, Clark said fossil evidence has led many scientists to conclude that many tree species now occupying former glaciated areas migrated north over an interval of a few thousand years from deep southern refuges along the southern Atlantic and Gulf coastal regions.

His and some other research groups have challenged that interpretation previously, although their objections "were never really taken seriously," Clark said. "One of the main issues for us was the fact that when you start to look at how far seeds disperse for modern trees and put that together with models of population spread, it’s very difficult for a population of trees to move that fast."

Instead of analyzing fossil data, Clark did population modeling in concert with McLachlan, a post-doctoral researcher with expertise in molecular analysis, and with Manos, who has expertise in molecular systematics, to assess the situation from a genetics standpoint. They focused on variations in heritable genetic sequences, or "haplotypes," that were isolated from the leaves of various kinds of modern trees.

The researchers used tree species such as red maple and beech that still grow throughout the region that would have been crossed in any ancient migrations. Clark said different trees of the same species can have a variety of different haplotype forms. But he and the others reasoned that any particular haplotype present in southern tree types at the end of the glacial period should still be found there today.

"Instead what we found is that a lot of these haplotypes in northern trees extend just south of what was once the ice sheet, but no further south," Clark said. "That’s exactly the distribution you would predict if they were confined to areas near the ice and moved further north."

Buffer zones near those ancient ice sheets are often envisioned as exceptionally cold and treeless. But Clark said his team’s findings suggest there was a more benign local environment.

"It means the trees were much closer to the ice than we thought. Maybe there weren’t the really severe winters there we traditionally think of. It could be that the climate of that time is something we don’t fully understand yet."

The team’s findings may affect current forecasts about how contemporary climate change might cause North American trees to migrate. The Duke group’s molecular evidence suggests that some species might not be able to relocate fast enough to adjust to rapid climate change, Clark said.

Monte Basgall | EurekAlert!
Further information:
http://www.duke.edu

More articles from Ecology, The Environment and Conservation:

nachricht Waste in the water – New purification techniques for healthier aquatic ecosystems
24.07.2018 | Eberhard Karls Universität Tübingen

nachricht Plenty of habitat for bears in Europe
24.07.2018 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

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: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>