Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nitrogen Research Shows How Some Plants Invade, Take Over Others

08.07.2009
Research at the University of Nebraska-Lincoln gives important new information on how plants can change "nitrogen cycling" to gain nitrogen and how this allows plant species to invade and take over native plants.

Biologists know that when plants battle for space, often the actual battle is for getting the nitrogen.

Now, research at the University of Nebraska-Lincoln gives important new information on how plants can change "nitrogen cycling" to gain nitrogen and how this allows plant species to invade and take over native plants.

In an article published July 6 in the scientific journal Proceedings of the National Academy of Sciences, UNL biologist Johannes "Jean" Knops demonstrates why one invasive plant species is replacing native species -- it's because of its ability to take up and hold on to nitrogen.

Biologists know that nitrogen is crucial to plant growth that invasive species often grow better and acquire more nitrogen, but have been uncertain about which mechanism allows invasive species to gain an advantage.

Over seven years' study at the Cedar Creek Ecosystem Science Reserve in central Minnesota, Knops and PhD candidate Ramesh Laungani studied the nitrogen pool and fluxes in the ecosystem that included seven grassland and forest species, including the Eastern white pine (Pinus strobus), a species that is rapidly invading Minnesota prairies. Over time they discovered that the pine had accrued nearly twice as much biomass as the next most productive species, and more than three times as much biomass relative to the other species.

"The higher productivity of the white pine is caused by an increased biomass nitrogen pool that was not driven by increased ecosystem level nitrogen inputs," Knops said. "But we found the white pine takes up nitrogen and holds on to it much longer, with leads to an accumulation of much more nitrogen in the plant and a depletion of nitrogen in the soil. We concluded high nitrogen residence time was the key mechanism driving the significantly higher plant nitrogen pool and the high productivity of that species."

In other words, pines mine the soil for organic nitrogen, decrease soil fertility and use this nitrogen to outcompete other species.

Knops, a plant and ecosystems ecologist, said the higher nitrogen residence time creates a positive feedback that redistributes nitrogen from the soil into the plant's nitrogen cycling. And this strengthened the species to support its invasion.

"What this higher nitrogen residence time means is that the plant is taking nitrogen from the soil and using it to make the plant grow more efficiently, and it also gives them an upper hand in being able to invade other species."

Biologists had identified six mechanisms that influence plant nitrogen use or acquisition: photosynthetic tissue allocation, photosynthetic nitrogen use efficiency, nitrogen fixation, nitrogen-leaching losses, gross nitrogen mineralization and plant nitrogen residence times. This study is the first to study all together and pinpoint the mechanism that explains why this pine is a successful invader.

Knops said he was somewhat surprised by the pines' ability to pull so much nitrogen out of the soil, especially in the degraded old fields that were studied.

Knowing this finding about nitrogen cycling with the white pine species may lead to important discoveries in how to stop invasions of other non-native species, like the Eastern red cedar, a destructive invader in the Great Plains; green ash, hackberry, or Chinese elms, or eventually to weedy exotic grasses that invade our native rangelands.

The study is the latest of several Knops has conducted at the Minnesota field site; this one began in 1999 with data taken in 2006. He has other projects in the mid-stage of 10- to 20-year timeframes, one looking at the establishment phase of pines, and another on grassland systems and their invasive species and abundance. He said his research field does require patience and longterm funding.

National Science Foundation, the University of Nebraska and the Center for Invasive Plant Species Management at Montana State University helped support the research.

Steve Smith | Newswise Science News
Further information:
http://www.unl.edu

More articles from Life Sciences:

nachricht Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>