Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Human Noise Has Ripple Effects on Plants

27.03.2012
Clamor affects more than birds and other animals

A growing body of research shows that birds and other animals change their behavior in response to human noise, such as the din of traffic or the hum of machinery.

But human clamor doesn't just affect animals.

Because many animals also pollinate plants or eat or disperse their seeds, human noise can have ripple effects on plants, too, finds a new study reported in the March 21, 2012, issue of the journal Proceedings of the Royal Society B.

In cases where noise has ripple effects on long-lived plants like trees, the consequences could last for decades, even after the source of the noise goes away, says lead author Clinton Francis of the National Science Foundation (NSF) National Evolutionary Synthesis Center in Durham, North Carolina.

In previous studies, Francis and colleagues found that some animals increase in numbers near noisy sites, while others decline.

But could animals' different responses to human noise have indirect effects on plants, too?

To find out, the researchers conducted a series of experiments from 2007 to 2010 in the Bureau of Land Management's Rattlesnake Canyon Wildlife Area in northwestern New Mexico.

The region is home to thousands of natural gas wells, many of which are coupled with noisy compressors for extracting the gas and transporting it through pipelines.

The compressors roar and rumble day and night, every day of the year.

The advantage of working in natural gas sites is they allow scientists to study noise and its effects on wildlife without the confounding factors in noisy areas like roadways or cities, such as pollution from artificial light and chemicals, or collisions with cars.

As part of their research, Francis and colleagues first conducted an experiment using patches of artificial plants designed to mimic a common red wildflower in the area called scarlet gilia.

Each patch consisted of five artificial plants with three "flowers" each--microcentrifuge tubes wrapped in red electrical tape--which were filled with a fixed amount of sugar water for nectar.

To help in estimating pollen transfer within and between the patches, the researchers also dusted the flowers of one plant per patch with artificial pollen, using a different color for each patch.

Din levels at noisy patches were similar to that of a highway heard from 500 meters away, Francis said.

When the researchers compared the number of pollinator visits at noisy and quiet sites, they found that one bird species in particular--the black-chinned hummingbird--made five times more visits to noisy sites than quiet ones.

"Black-chinned hummingbirds may prefer noisy sites because another bird species that preys on their nestlings, the western scrub jay, tends to avoid those areas," Francis said.

Pollen transfer was also more common in the noisy sites.

If more hummingbird visits and greater pollen transfer translate to higher seed production for the plants, the results suggest that "hummingbird-pollinated plants such as scarlet gilia may indirectly benefit from noise," Francis said.

Another set of experiments revealed that noise may indirectly benefit some plants, but is bad news for others.

In a second series of experiments at the same study site, the researchers set out to discover what noise might mean for tree seeds and seedlings, using one of the dominant trees in the area--the piñon pine.

Piñon pine seeds that aren't plucked from their cones fall to the ground and are eaten by birds and other animals.

To find out if noise affected the number of piñon pine seeds that animals ate, the researchers scattered piñon pine seeds beneath 120 piñon pine trees in noisy and quiet sites, using a motion-triggered camera to figure out what animals took the seeds.

After three days, several animals were spotted feeding on the seeds, including mice, chipmunks, squirrels, birds and rabbits.

But two animals in particular differed between quiet and noisy sites--mice, which preferred noisy sites, and western scrub jays, which avoided them altogether.

Piñon pine seeds that are eaten by mice don't survive the passage through the animal's gut, Francis said, so the boost in mouse populations near noisy sites could be bad news for pine seedlings in those areas.

In contrast, a single western scrub jay may take hundreds to thousands of seeds, only to hide them in the soil to eat later in the year.

The seeds they fail to relocate will eventually germinate, so the preference of western scrub jays for quiet areas means that piñon pines in those areas are likely to benefit.

In keeping with their seed results, the researchers counted the number of piñon pine seedlings and found that they were four times as abundant in quiet sites compared with noisy ones.

It may take decades for a piñon pine to grow from a seedling into a full-grown tree, Francis said, so the consequences of noise may last longer than scientists thought.

"Fewer seedlings in noisy areas might eventually mean fewer mature trees, but because piñon pines are so slow-growing the shift could have gone undetected for years," he said.

"Fewer piñon pine trees would mean less critical habitat for the hundreds of species that depend on them for survival."

Other authors of the study include Catherine Ortega, most recently of Fort Lewis College, and Alexander Cruz and Nathan Kleist of the University of Colorado, Boulder.

Media Contacts
Cheryl Dybas, NSF (703) 292-7734 cdybas@nsf.gov
Robin Ann Smith, NESCENT (919) 668-4544 rsmith@nescent.org
Related Websites
NSF National Evolutionary Synthesis Center: http://www.nescent.org/
he 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 is $7.0 billion. NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and other institutions. Each year, NSF receives over 50,000 competitive requests for funding, and makes about 11,000 new funding awards. NSF also awards nearly $420 million in professional and service contracts yearly.

Cheryl Dybas | EurekAlert!
Further information:
http://www.nsf.gov

More articles from Life Sciences:

nachricht Single-stranded DNA and RNA origami go live
15.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

nachricht New antbird species discovered in Peru by LSU ornithologists
15.12.2017 | Louisiana State University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>