Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chestnuts used chemicals to dominate southern Appalachian forests

11.10.2002


USDA Forest Service research confirms that chemicals in the leaves of the American chestnut suppress the growth of other trees and shrubs-and probably played a part in the species’ past dominance of the southern Appalachian forest.



Southern Research Station ecologist Barry Clinton (Coweeta Hydrologic Laboratory)-with fellow researchers from Clemson University and the University of North Carolina-Chapel Hill-tested the effects of fallen chestnut leaves on five tree species that historically competed with the American chestnut before chestnut blight destroyed almost all of the great trees.

"American chestnut reached its greatest size and stand density in the southern Appalachians, where it may have taken up almost 50 percent of the forest canopy," said Clinton. "Chestnut’s dominance has traditionally been attributed to its rapid growth rate, resistance to rot and fire, and ability to thrive on poor soil. Our experiments show that allelopathy may also have contributed to its dominance."


Allelopathy is the secretion by plants of chemicals that inhibit the growth or reproduction of competing plant species. Black walnut is a prime example of allelopathy: the tree produces the chemical Juglone, which suppresses the growth of trees, shrubs, and other vegetation. Other allelopathic trees include sycamore, eucalyptus, and hackberry.

Clinton and his fellow researchers tested the effects of an extract made from the leaves of young American chestnut trees on the seeds of red maple, eastern white pine, eastern hemlock, yellow-poplar, and the native shrub rosebay rhododendron. Under controlled laboratory conditions, the researchers found that the extracts inhibited the germination of eastern hemlock and rosebay rhododendron. Eastern hemlock is a major species along the mountain streams of the Southern Appalachians. Rosebay rhododendron has become the dominant shrub on moist sites, where it interferes with hardwood regeneration and threatens the diversity of cove forests.

"Our results suggest that chestnut may have had a controlling effect on rhododendron germination and growth in the past," said Clinton, "and that the rapid encroachment of this shrub in the 20th century may be largely due to the end of the tree’s allopathic influence."

One of the most interesting results of the experiment was the ability of chestnut leaf extract to suppress the germination of eastern hemlock, which has steadily migrated into the chestnut-blighted areas of southern Appalachian forests.

"We have anecdotal evidence that eastern hemlock, which also has allelopathic qualities, can inhibit chestnut seeds from sprouting," said Clinton. "Historical accounts show that these trees rarely occurred together in pre-blight forests. We are starting to get a picture of the dynamic competitive relationship that once existed between these two important southern Appalachian tree species."

Results from the experiment on chestnut allelopathy are published in the July 15, 2002 issue of Forest Ecology and Management, which is available from the SRS website in full text formats at http://www.srs.fs.fed.us/pubs/viewpub.jsp?index=4723.

For more information: Barry Clinton at (828-524-2128) or bclinton@fs.fed.us

Barry Clinton | EurekAlert!
Further information:
http://www.srs.fs.fed.us/pubs/viewpub.jsp?index=4723

More articles from Life Sciences:

nachricht The birth of a new protein
20.10.2017 | University of Arizona

nachricht Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>