Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Alien plants attack using 'resource conservation' as weapon, researchers say

03.05.2007
One of the most serious and least understood threats to the world's ecosystems is the problem of invasive species-exotic plants, animals and other organisms that are brought into habitats and subsequently spread at a rapid rate, often replacing native species and reducing biodiversity.

Invaders thrive best in regions where there is an abundance of materials for growth, such as water, nutrients and light. Biologists have long assumed that alien species pose less of a threat in resource-poor environments because they are less able to compete with indigenous plants, which have adapted to their habitats over thousands of years. But a new study by Stanford University researchers finds that invasive plants can flourish in low-resource environments by adopting efficient ways to use available resources.

The finding, which sheds new light on how invaders achieve success, may change the way scientists think about invasive species and how to curb them, according the authors of the study published in the April 26 issue of the journal Nature.

"What was very intriguing to us is that there are invasive species that are capable of invading low-resource systems," said Jennifer Funk, a postdoctoral fellow in the Stanford Department of Biological Sciences and lead author of the study. "Typically people think low-resource systems aren't invasible. People think of the native plants as having a home-field advantage, because they evolved there."

Smart plant growth

Plants depend on sunlight, nutrients and water to survive, and a shortage of any one of these will restrict how fast they can grow. When plants use these inputs more efficiently, however, they can photosynthesize-and thus grow and spread-faster, according to Funk and Vitousek.

To compare the resource-use efficiencies of alien and native plants, the researchers studied three ecosystems in Hawaii-a forested area with limited light, volcanic soils with low nutrients and a desert. They compared 19 invaders with 19 closely related indigenous plants-for example, an invasive raspberry versus a native raspberry. Using an electronic device that clamped onto the leaves of the plants, the scientists controlled the amount of light reaching the leaf and then measured photosynthesis and water-use rates. Later, they ground up and analyzed the leaves in a laboratory to determine nutrient content. By calculating the ratio of resource use to the rate of photosynthesis, the scientists were able to determine the resource-use efficiency for each plant.

"Invasive plants were more efficient on short-time scales, but overall there was no difference in the long term," Funk said. "We were surprised that the invasive plants were not at a disadvantage under conditions where resources were scarce."

Knowing your foe

These results have important implications for controlling invasive species, said Chris Field, professor of biological sciences at Stanford and director of the Carnegie Institution's Department of Global Ecology.

"If you want to manage an invasive, you need to know what the characteristics of the invasives are and target your strategy to those characteristics," he said.

Funk pointed to recent experiments that tried to eliminate invaders by deliberately reducing available resources-for example, by mixing sugar into the soil to lock up nutrients or by blocking sunlight with tarps. But these experiments had relatively limited success. "Our results can maybe explain why that method didn't work for all the invasive species," Funk said.

Current techniques for fighting invasive species typically involve early detection followed by a variety of removal methods, such as weed-whacking or introducing natural predators of the invasive plants, said study co-author Peter Vitousek, professor of biological sciences at Stanford.

To determine which species warrant action, some government agencies in several countries, including the U.S. National Park Service, maintain comprehensive lists of potential invaders, he said. Scientists look at a variety of factors to assess which plants should be included on the lists, but models for determining which invasive species pose the greatest threat are far from complete, Funk added.

"With this new information, we can now take a look at those lists with the thought in mind that we better consider adding species that are really resource efficient," Vitousek said. "And then we can hunt those down."

Mark Shwartz | EurekAlert!
Further information:
http://www.stanford.edu/news/
http://www.stanford.edu/group/Vitousek/

More articles from Ecology, The Environment and Conservation:

nachricht Value from wastewater
16.08.2017 | Hochschule Landshut

nachricht Species Richness – a false friend? Scientists want to improve biodiversity assessments
01.08.2017 | Carl von Ossietzky-Universität Oldenburg

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>