California: El Nino's fall and winter weather is expected to create perfect conditions to spread Sudden Oak Death Syndrome. Now UC Berkeley officials are warning West Coast residents to help prevent the deadly water-born mold, called Phytophthora ramorum, from threatening California tribal lands.
Experts at the California Oak Mortality Task Force say public education is a key factor in protecting oaks and tanoaks from the deadly disease.
Since the 1990s, more than 1,000,000 of the state's oak and tanoak trees have died from this pathogen. At least another 1,000,000 are infected. Mortality rates range from 50% - 90%. The water mold also causes twig and foliage diseases known as ramorum blight. Ramorum blight affects many species including bay laurel, Douglas fir and coast redwood.
Dave Rizzo of UC Davis said infection levels will rise dramatically if a full blown El Niño hits California. "It is a disease characterized by waves of infection that normally coincide with wet years,” he said.
California tribes are deeply concerned that the disease will further impact tribal cultures already suffering from over 300 years of genocide and development. Oaks and tanoaks are central to these tribal cultures -- acorns were once the principal food of many California tribes. The traditional gathering and preparations of acorns was -- and is still -- a time for families to come together and share stories and cultural knowledge with younger generations.
“The tribes’ overarching concern is for the oaks, since they are such an important food plant for both humans and for wildlife that are also culturally important such as deer and acorn woodpeckers,” said Jennifer Kalt from the California Indian Basketweavers Association. Many threatened plants are used for weaving and other cultural uses.
The pathogen was accidentally imported in the late 20th century. It can be easily spread on pant legs, shoes, tires and auto bodies, or from transporting basketry or medicinal plants out of an infected area.
“It should be assumed that the leaves, twigs and wood of host species, soil and water in an infected area are all infectious," said one official. "Movement of any of these substrates, or use of recycled water without chemical treatment, should be avoided in order to prevent further spread of the pathogen.”
Preventative treatments, including pesticides, must be applied in the fall and spring to arm trees with as much resistance as possible.
Tribes are also using other prevention protocols. Basketweavers, medicine people and other cultural practitioners have altered gathering practices to prevent spreading the disease. Gatherers stay out of quarantined lands during wet seasons. They also wash mud and soil off vehicles, equipment, clothing, and footwear with a bleach solution before leaving what may be an infected area when working in gathering areas.
Most of all, they are praying for an end to the epidemic that threatens their culture.
Photos: USDA and Debra Utacia Krol