An American beech tree suffers large, woundlike
cankers caused by pathogenic Neonectria. These fungi are inflicting
serious damage to hardwood forests across the northeastern United States.
Photo by Linda Haugen, USDA Forest
Thanks to Systematics, Battle Is on to Save a Great
By Erin Peabody
September 26, 2006
New England's famous fall colors
just wouldn't be the same without the fiery coppers and reds of the American
beech tree. Unfortunately, this key member of North America's eastern hardwood
forests is slowly being eaten alive by a group of fungi that have, up to now,
baffled and confused researchers.
Now, thanks to systematists with the Agricultural Research Service in Beltsville,
Md., it's clear that two distinct fungi in the Neonectria genus should
be targeted in the scramble to keep beech trees out of harm's way. Systematics
is the study of how the world's myriad organisms are identified, described and
Causing tree dieback and sometimes death, beech bark disease (BBD) has so
far left its biggest scar on the nation's northeastern forests. Creeping
southward along the spine of the Appalachian Mountains, the disease currently
threatens to invade vast beech tree stands across parts of Pennsylvania and
Like genealogy experts mapping a family tree, ARS researchers
Castlebury at the agency's
Botany and Mycology Laboratory sorted out the murky relationships between
the many Neonectria fungi that appeared linked to BBD.
They've now confirmed that two Neonectria species are of real
concern. One is N. faginata, which may be native to North America. The
other, N. ditissima, attacks multiple hardwoods, including fruit trees.
This information will be vital to researchers trying to breed trees
resistant to BBD and to inspectors charged with preventing pathogenic fungi
from entering the country.
If you're in the Washington, D.C., area and are interested in learning more
about the many ways ARS systematists like Rossman and Castlebury have helped
safeguard the nation's agriculture and natural resources, you're in luck!
An interactive exhibit, entitled "Systematics: Roots and
Relationships," is now on display at the U.S. Botanic Garden (USBG) on the National
Mall. It runs through October 16. See the USBG website at:
www.usbg.gov for further information.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.