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 dense vessel network regulates formation of thrombocytes in the bone marrow
25.07.2017 | Rudolf-Virchow-Zentrum für Experimentelle Biomedizin der Universität Würzburg

nachricht Fungi that evolved to eat wood offer new biomass conversion tool
25.07.2017 | University of Massachusetts at Amherst

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA mission surfs through waves in space to understand space weather

25.07.2017 | Physics and Astronomy

Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds

25.07.2017 | Earth Sciences

The dense vessel network regulates formation of thrombocytes in the bone marrow

25.07.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>