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 Two Group A Streptococcus genes linked to 'flesh-eating' bacterial infections
25.09.2017 | University of Maryland

nachricht Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Fraunhofer ISE Pushes World Record for Multicrystalline Silicon Solar Cells to 22.3 Percent

25.09.2017 | Power and Electrical Engineering

Usher syndrome: Gene therapy restores hearing and balance

25.09.2017 | Health and Medicine

An international team of physicists a coherent amplification effect in laser excited dielectrics

25.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>