Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mellow in Europe, crazy in America

28.02.2007
UVM study shows new way that benign plants become invasive

Reed canarygrass is a bit like some people on vacation. At home, they stay on their side of the fence, and speak nicely with the neighbors. But jet them into Las Vegas and by week's end they are shoving other people out of the way in the casino.

Similarly, the reed canarygrass is well-settled in its native European range, not pushing out other species or expanding its terrain. But, introduced into the United States, it's running amok ecologically, choking out native plants in wetlands. Once praised as a fine forage crop, the grass is now considered an invasive pest in about ten states and its range is growing.

Studying this grass as a model, Jane Molofsky, associate professor of plant biology at the University of Vermont and her French colleague, Sebastien Lavergne, have discovered a novel mechanism to explain the surprising conversion of some plant species from quiet neighbor at home into expansive bully in new territory.

As they report in the February 27, 2007, edition of the Proceedings of the National Academy of Sciences (PNAS), the invasive power of this grass, brought to America in the mid-19th century and many times thereafter, comes not from any one individual plant, but from this history of multiple introductions from different regions of Europe.

Over decades, US farmers and others have planted the grass as livestock feed, for erosion control, and for wastewater treatment—with plants taken from places as far apart as France, the Czech Republic and Finland.

These multiple introductions, and subsequent interbreeding, create a kind of biological stacked deck: drawing on genetic variety from across the European continent, new strains have emerged in the US with higher genetic diversity and more potentially advantageous qualities than their species brethren across the Atlantic.

"It's not that you're taking the ones in France and moving them to the US and they're suddenly invasive," Molofsky said, looking over a green swath of reed canarygrass growing in a UVM greenhouse, "its that you move some plants, and then you move some from somewhere else and they recombine here to form something better, genetic superstars."

The result: in America, reed canarygrass has developed traits, like faster emergence in the spring and larger root biomass, that allow it to become a rapid colonizer. In short, the grass is still the same species, but it has quickly evolved to be invasive.

And this has significance far beyond the headache of reed canarygrass. A "fundamental implication of our paper is that not only do invasive species evolve but we show that they can evolve extremely rapidly," Sebastian Lavergne notes, striking a blow at the conventional view that evolution occurs at very slow rates.

"If you drive around in Vermont you'll see that it has taken over whole areas of wetlands, and out West it clogs waterways and takes over irrigation ditches," says Molofsky. "It's a big problem in Alaska: it's preventing salmon runs, its changing habitats. It's becoming a larger and larger problem."

Molofsky's greenhouse- and field-based study, funded by the US Department of Agriculture, shows why. Thanks to a large network of European collaborators, she and her students collected plants from the both the center and edge of the native range in Europe, getting individuals from southern France and the Czech Republic. They also collected from the invasive range center in Vermont and the edge in North Carolina.

They discovered that the grass in its native Europe show a typical decrease of genetic diversity at the edge of the range, constraining its ability to adapt and expand into new conditions. But in the US invasive range, they found a different story. There, the invasive plants thrive on infusions of Europe-wide genetic material, allowing them to quickly adapt to new conditions and continue their quiet march into new fields and wetlands.

"The problem is that these invasive species at the range margin are maintaining all of the genetic diversity which represents a substrate for future evolution," Molofsky says, "so when climates begin to change we expect that some individuals from those populations will be able to grow in new conditions. But it is unlikely that native species have maintained enough genetic variability to move with rapid climate changes." Invaders persist, natives expire.

For land managers, farmers, nursery owners and others the implications of this study are also weighty. It seems likely that a considerable number of horticultural and agricultural plants that currently seem benign could become invasive by the same mechanism that affected reed canarygrass, and that climate change will increase the intensity of this problem.

"If people had stopped introducing the grass, we might not have this problem now," Molofsky said, "but it seemed fine then."

Other plants may soon follow this path. "Some in the nursery industry argue, 'well, we can have barberry here, because its not invasive in Vermont,' My point is, 'yes, not now, but keep introducing it and let it mix and with climate change we'll have it later,'" Molofsky says. "Just keep planting it out there, and 20 years from now when it's 2 degrees warmer you're going to see it in the forest."

"Some people are thinking of species as static, like they can't evolve," she says. Her study shows otherwise.

Joshua Brown | EurekAlert!
Further information:
http://www.pnas.org/
http://www.uvm.edu

More articles from Agricultural and Forestry Science:

nachricht Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli
26.04.2017 | University of the Basque Country

nachricht New data unearths pesticide peril in beehives
21.04.2017 | Cornell University

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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Bare bones: Making bones transparent

27.04.2017 | Life Sciences

Study offers new theoretical approach to describing non-equilibrium phase transitions

27.04.2017 | Physics and Astronomy

From volcano's slope, NASA instrument looks sky high and to the future

27.04.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>