Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Earth Day: Big Ecosystem Changes Viewed Through the Lens of Tiny Carnivorous Plants

24.04.2013
Researchers use pitcher plants to identify signs of trouble dead ahead
In one drop of water are found all the secrets of all the oceans.
---Kahlil Gibran
What do a pond or a lake and a carnivorous pitcher plant have in common?
The water-filled pool within a pitcher plant, it turns out, is a tiny ecosystem whose inner workings are similar to those of a full-scale water body.

In scientists' eyes, each leaf of the northern pitcher plant is a small ecosystem.
Credit: Aaron Ellison

Whether small carnivorous plant or huge lake, both are subject to the same ecological "tipping points," of concern on Earth Day--and every day, say scientists.

The findings are published in this week's issue of the journal Proceedings of the National Academy of Sciences.

In the paper, ecologists affiliated with the National Science Foundation (NSF) Harvard Forest Long-Term Ecological Research site in Massachusetts offer new insights about how such tipping points happen.

"Human societies, financial markets and ecosystems all may shift abruptly and unpredictably from one, often favored, state to another less desirable one," says Saran Twombly, program director in NSF's Division of Environmental Biology, which funded the research.

"These researchers have looked at the minute ecosystems that thrive in pitcher plant leaves to determine early warning signals and to find ways of predicting and possibly forestalling such 'tipping points.'"

Life in lakes and ponds of all sizes can be disrupted when too many nutrients--such as in fertilizers and pollution--overload the system.

When that happens, these aquatic ecosystems can cross "tipping points" and change drastically. Excess nutrients cause algae to bloom. Bacteria eating the algae use up oxygen in the water. The result is a murky green lake.

"The first step to preventing tipping points is understanding what causes them," says Aaron Ellison, an ecologist at Harvard Forest and co-author of the paper. "For that, you need an experiment where you can demonstrate cause-and-effect."

Ellison and other scientists demonstrated how to reliably trigger a tipping point.

They continually added a set amount of organic matter--comparable to decomposing algae in a lake--to a small aquatic ecosystem: the tiny confines of a pitcher plant, a carnivorous plant native to eastern North America.

Each pitcher-shaped leaf holds about a quarter of an ounce of rainwater. Inside is a complex, multi-level food web of fly larvae and bacteria.

"The pitcher plant is its own little ecosystem," says Jennie Sirota, a researcher at North Dakota State University and lead author of the paper.

Similar to lake ecosystems, oxygen levels inside the water of a pitcher plant are controlled by photosynthesis and the behavior of resident organisms--in this case, mostly bacteria.

Ellison says that conducting an experiment with bacteria is like fast-forwarding through a video.

"A bacterial generation is 20 minutes, maybe an hour," he says. "In contrast, fish in a lake have generation times of a year or more.

"We would need to study a lake for 100 years to get the same information we can get from a pitcher plant in less than a week."

The same mathematical models, Ellison and colleagues discovered, can be used to describe a pitcher plant or a lake ecosystem.

To approximate an overload of nutrients in pitcher-plant water, the team fed set amounts of ground-up wasps to the plants.

"That's equivalent to a 200-pound person eating one or two McDonald's quarter-pounders every day for four days," says Ellison.

In pitcher plants with enough added wasps, an ecosystem tipping point reliably occurred about 45 hours after the start of feeding.

The scientists now have a way of creating tipping points. Their next step will be to identify the early warning signs.

"Tipping points may be easy to prevent," says Ellison, "if we know what to look for."

Other authors of the paper are Benjamin Baiser of Harvard Forest and Nicholas Gotelli of the University of Vermont.

Media Contacts
Cheryl Dybas, NSF (703) 292-7734 cdybas@nsf.gov
Clarisse Hart, Harvard University (978) 756-6157 hart3@fas.harvard.edu
Related Websites
NSF "Discoveries in Long-Term Ecological Research" Publication: http://www.nsf.gov/pubs/2013/nsf13083/nsf13083.pdf?WT.mc_id=USNSF_25&WT.mc_ev=click
NSF LTER Network: http://www.lternet.edu
NSF Harvard Forest LTER Site: http://harvardforest.fas.harvard.edu/
NSF Discovery Article: At Harvard Forest, Are Autumn's Reds and Golds Passing Us By?: http://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=125511

The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2012, its budget was $7.0 billion. NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and other institutions. Each year, NSF receives about 50,000 competitive requests for funding, and makes about 11,500 new funding awards. NSF also awards about $593 million in professional and service contracts yearly.

Cheryl Dybas | EurekAlert!
Further information:
http://www.nsf.gov
http://www.nsf.gov/news/news_summ.jsp?cntn_id=127651&org=NSF&from=news

More articles from Ecology, The Environment and Conservation:

nachricht Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

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: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

A Nano-Roundabout for Light

09.12.2016 | Physics and Astronomy

Further Improvement of Qubit Lifetime for Quantum Computers

09.12.2016 | Physics and Astronomy

New weapon against Diabetes

09.12.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>