Forest Health Protection
1720 Peachtree Road, NW
Room 816 N
Atlanta, GA 30309
Phone: (404) 347-7478
Fax: (404) 347-1880
Sudden Oak Death
ramorum (Pr) is a pathogen new to science that
causes 3 distinctly different diseases- ramorum leaf blight, ramorum shoot
dieback, and a killing stem canker disease of oak and tanoak better known
as sudden oak death. It is a fungus-like organism not native to North
America and many species and cultivars of popular woody landscape plants
are counted among the hosts. Pr poses an international risk to vulnerable
oak and tanoak ecosystems via accidental introduction on infected nursery
- Pr was found in
the mid-1990's in European ornamental nurseries on Rhododendron and
Viburnum and simultaneously in central coastal CA killing coast live
and CA black oaks.
- The first Pr-infected
ornamental nursery stock in CA was detected in 2001, and APHIS promulgated
rules governing interstate commerce in host species in 2002. International
quarantines have been put in place by the EU, Canada, South Korea, and
- The US nursery
industry was not heavily impacted until 2003 when infected stock was
found in CA, OR, and WA.
- The host range
has since grown to 42 genera of nursery and forest plants representing
all forest strata from the herbaceous understory to woody canopy species.
- The geographic
range in North American forest landscapes is currently limited to 14
central coastal CA counties and one county in southwest OR. However,
1.5 million potentially infected nursery host plants were accidentally
shipped to all 50 states from a southern CA nursery in 2003-04 and again
in separate incidents in 2004-05.
- FHM-Research synthesized
known pathogen epidemiology (hosts, environment, and introduction pathways)
into a national risk map that guides early detection surveys.
- National survey
protocols are written and training conducted by R8-FHP. State forestry
agency cooperators conduct the field surveys and submit plant samples
to molecular diagnostic labs in state universities.
- A pilot survey
to develop methods in 7 high-risk eastern states in woody ornamental
nursery perimeters and general forest areas was funded by FHM in '03.
172 locations were surveyed; 1,116 symptomatic host samples were negative
for Pr. (Accidental introduction was occurring at the time, but this
fact was not known until March of '04.)
- The discovery
of accidental introduction resulted in the expansion of the survey to
36 states in '04. Cumulative results to date are: 1,119 locations surveyed;
5,633 samples processed; 2 positive for Pr, both from San Francisco
Co. CA (surrounded by known positive counties).
- The survey will
be expanded to 38 states in '05. Total funding = $0.4 million in '03;
$1.3 million each in '04 and '05 for a total of $3.0 million over 3
years, all through FHM.
- Pr has been confirmed
in nursery stock in 20 states (a few in landscapes in GA and SC), but
is not known to occur in forest ecosystems outside the infested west
- Highest risk areas
are in the forest interface in urban and wildland settings where infected
ornamentals have been planted and remain undetected. The Cooperative
Extension Service has the mandate here, but may not be adequately trained
or funded to attack the problem.
- Cost sharing requirements
for our state cooperators sometimes impede survey logistics.
- Continued interagency
cooperation with APHIS, state departments of agriculture, state forestry
agencies, FHM, and FHP.
- Research needs
in epidemiology, particularly as concerns eastern species and early
detection methods (e.g. stream water sampling and baiting for Pr).
- Based on past
history, it is not a matter of "if", but "when"
Pr will gain a foothold in eastern oak forests. Due to a lack of basic
epidemiological research on eastern species, the range of outcomes is
extremely uncertain- from innocuous to a potential chestnut blight scenario.
- FHP continues
to cooperate with APHIS and state partners in the development of early
detection, delimitation, containment, and eradication strategies. Containment
and eradication protocols for forest ecosystems are in APHIS review
at this time.
and Plant Health Inspection Service
Oak Mortality Task Force
Forest Service, Northeastern Area
USDA Forest Service
Southern Region FHP
200 Weaver BLVD
Asheville, NC 28804
Phone: (828) 257-4322