Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Team discovers a significant role for nitrate in the Arctic landscape

26.03.2018

Nitrogen, an essential plant nutrient, is most readily absorbed by plants in its ammonium and nitrate forms. Because of the very low nitrate levels found in arctic tundra soil, scientists had assumed that plants in this biome do not use nitrate. But a new study co-authored by four Marine Biological Laboratory (MBL) Ecosystems Center scientists challenges this notion. The study has important implications for predicting which arctic plant species will dominate as the climate warms, as well as how much carbon tundra ecosystems can store.

The study, published in Proceedings of the National Academy of Sciences, found that plants in northern Alaska's tussock tundra took up nitrate at comparable rates to vegetation in nitrate-rich ecosystems. Nitrate contributed about one-third of the nitrogen the tundra plants used. Some of the species studied, such as Polygonum bistorta, a pink flowering plant, took up nitrate at even higher rates than species found in low-latitude, high-nitrate environments.


Ecologists have discovered that arctic tundra plants take up much more nitrate than previously thought. Some species, such as the pink flowering plant Polygonum bistorta, take up even more nitrate than plants in low latitude, high-nitrate environments.

Credit: Allen Chartier

The findings are important in the context of human-caused climate change, which is expected to increase nitrogen, and potentially nitrate, levels in tundra soil. As the climate warms, the microbial processes that generate nitrate could speed up. In addition, permafrost -- a layer of soil below the surface that remains frozen throughout the year -- could thaw, adding additional nitrogen to the ecosystem. Some of this nitrogen could be converted to nitrate.

The tussock tundra covers a large part of northern Alaska and is currently composed of sedges, herbaceous ground cover, and woody shrubs (about a third coverage for each). The landscape's productivity is limited by nitrogen availability. If released from this limitation, woody shrub species, such as birch and willow, could become more dominant and shade out other plants as the climate warms. The discovery that nitrate is an important nitrogen source for tundra plants will need to be factored into future projections of species composition.

"As the nutrients start cycling faster and the vegetation starts growing faster, that should stimulate all the vegetation on the tundra. After a while, the woody species should be able to overtop the ones that don't have stems, that can't stand up that high.

So you tend to lose the sedges and the mosses and the lichens," explained study co-author Ed Rastetter, a senior scientist at the MBL Ecosystems Center and principal investigator for the National Science Foundation's Arctic Long-Term Ecological Research site at Toolik Lake, Alaska, where part of the research was conducted.

Because nitrogen and carbon cycles are tightly coupled, the team's discovery might also alter projections of carbon storage or release from arctic ecosystems as the climate warms. The world's permafrost is packed with the remnants of plants and animals accumulated over thousands of years, and it contains twice as much carbon as is currently in the atmosphere.

Rastetter stresses that more research is needed to confirm the study's findings and to better understand the importance of nitrate relative to other forms of nitrogen in arctic tundra ecosystems.

###

MBL Ecosystems Center scientists Gaius Shaver, Anne Giblin, James Laundre and Rastetter contributed to the study. They collaborated with researchers from China, Japan, Norway and the United States.

Citation:

Xue-Yan Liu et al (2018) Nitrate is an important nitrogen source for Arctic tundra plants. Proc. Natl. Acad. Sci. doi: 10.1073/pnas.1715382115

The Marine Biological Laboratory (MBL) is dedicated to scientific discovery - exploring fundamental biology, understanding marine biodiversity and the environment, and informing the human condition through research and education. Founded in Woods Hole, Massachusetts in 1888, the MBL is a private, nonprofit institution and an affiliate of the University of Chicago.

Media Contact

Diana Kenney
dkenney@mbl.edu
508-289-7139

 @mblscience

http://www.mbl.edu 

Diana Kenney | EurekAlert!
Further information:
http://www.mbl.edu/blog/team-discovers-a-significant-role-for-nitrate-in-the-arctic-landscape/
http://dx.doi.org/10.1073/pnas.1715382115

More articles from Earth Sciences:

nachricht Clear as mud: Desiccation cracks help reveal the shape of water on Mars
20.04.2018 | Geological Society of America

nachricht Hurricane Harvey: Dutch-Texan research shows most fatalities occurred outside flood zones
19.04.2018 | European Geosciences Union

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

One step closer to reality

20.04.2018 | Life Sciences

The dark side of cichlid fish: from cannibal to caregiver

20.04.2018 | Life Sciences

Diamond-like carbon is formed differently to what was believed -- machine learning enables development of new model

19.04.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>