SEOUL, South Korea (AP) _ Fearing a deadly tree fungus, South Korea said Wednesday it will impose a ban on imports of oak seeds and lumber from California.

The disease has not shown up in Korea, where oak trees comprise 26 percent of the country's forests, the Agriculture and Forestry Ministry said in a statement.

The ban will go into effect on Aug. 16.

A species of fungus called Phytophthora causes the disease known as Sudden Oak Death.

Since the disease first showed up in 1995 in Mill Valley, Calif., it has killed hundreds of thousands of trees from Sonoma County to Big Sur.

It attacks tanoak, coastal live oak and black oak and scientists still don't know how the disease is spread.