Posted on 04/09/2003 8:22:56 AM PDT by cogitator
Sudden Oak Death Impacting Other Species
Sudden Oak Death Impacting Other Species
BERKELEY, California, April 8, 2003 (ENS) - Researchers believe a highly contagious disease that has killed tens of thousands of native California oaks could be spread by a wide range of other species.
Sudden Oak Death (SOD) was first reported in 1995 in Marin County, California in oaks and tanoaks, but now scientists think that nearly all the main tree species in California's forests, as well as forest shrubbery and undergrowth, may act as hosts for the disease.
"SOD's reproductive strategy may make it able to persist indefinitely in infested forests and may affect the success of future regeneration and restoration efforts," according to Matteo Garbelotto, an extension forest pathologist and adjunct professor at the University of California, Berkeley who has been researching the disease.
"What we hypothesized and what we are now confirming is that SOD is not spreading via the oaks, but is instead using a huge range of native plants for reproduction," he explained.
The disease is caused by a funguslike brown larvae related to the organism that caused the nineteenth century Irish potato famine. Scientists are not certain how the disease got to California, but some suspect through imported nursery plants.
It appears to use the leaves, branches and stems of its hosts to reproduce, leaving behind lesions and leaf discoloration. It does not kill the host plant outright, according to scientists, but repeated SOD infections are likely to weaken the plant over time, negatively impacting its growth and making it susceptible to other diseases and insects.
Scientists knew the disease was spread by plants other than oaks, including plants from the rhododendron family, but evidence that it could have such a broader range of potential hosts brings good and bad news to those trying to combat the disease.
It increases the potential impact on California's forests and ecosystems, but also gives scientists greater understanding of the disease.
"The more we know about how SOD is spreading, the greater the chances for finding a way to control it," Garbelotto said.
An International Symposium on SOD will be held online from April 21 to May 4 by the American Phytopathological Society.
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