By GENEVIEVE BOOKWALTER
The log that just went into the wood stove might be 400 years old.
According to a recent report from the University of Arkansas, California foothills' blue oaks are part of the largest remaining old-growth forest in the United States.
Dating back 200 to 500 years, blue oaks which are not the same as valley oaks don't rival the ancient redwoods. Those can stand for more than 1,000 years.
But because the oaks hold little timber value, they still cover more than 4,000 square miles of the California foothills. Although they're not tightly packed like Ponderosa pine groves, some scientists still consider foothills blue oaks the largest ancient forest in the country.
The data comes from the University of Arkansas' Tree-Ring Laboratory in Fayetteville, Ark. Researchers journeyed to the foothills for 16-inch core samples from oaks in the Sierra Nevada and the California Coastal Range. A core sample is a long, thin cylinder of wood taken from the trunks of trees.
Researchers took the cores back to Arkansas to count the rings and estimate not only age, but drought history, because the size of a tree's ring can tell how much rain fell the year the ring was formed.
Scientists use tree-ring data in seismology, archaeology and history studies as well.
Blue oaks are small, strong trees not valued for timber, although they are a hardwood.
"The wood is so tough we broke a number of bores," said Arkansas Professor Malcolm Cleaveland, who has been working with tree rings since beginning his master's thesis in 1972.
Arkansas' Tree-Ring Laboratory has received funds from the U.S. National Science Foundation, National Oceanic and Atmospheric Administration, National Park Service and U.S. Geological Survey.
On the Stanislaus National Forest, plant pathologist John Pronos in the Sonora supervisor's office said California black oaks dominate within the forest's borders.
Blue oaks flourish between 1,000- and 3,000-foot elevation, Pronos said. They are characterized by bluish-green leaves and light-colored bark.