When David Milarch first visited Northern California in 1968, he thought he would see avenues of coast redwoods 100 miles long. What he found instead was a “moonscape,” he said. Nearly 40 years later, the Michigan arborist has returned to the region to realize his dream of preserving and restoring the most ancient of these trees using the latest advances in genetic cloning.
“What does this tree's immune system have in it that it has survived when other trees haven't?” Milarch asked, leaning against a massive, shaggy trunk of a redwood he's dubbed “Grandma.” He estimates the tree is at least 800 years old.
On a foggy Tuesday in Marin County, about 25 miles north of San Francisco, Milarch assembled a team of crack tree climbers who used ropes and harnesses to clamber more than 100 feet into the treetops at Roy's Redwoods Preserve.
The workers clipped boughs from some of the preserve's oldest and tallest trees to get genetically pure samples of some of nature's ultimate survivors.
Milarch, 58, believes these trees can provide the toughest possible stock for a kind of “genetic savings account.” He hopes that material can be used to restore old-growth redwoods in their native range up and down the state.
About 95 percent of the original forest has been cut down over the last few hundred years.
Average mature redwoods stand between 200 to 240 feet tall and have diameters of 10 to 15 feet. The tallest trees have been measured at more than 370 feet, making coast redwoods the tallest living organisms in the world. The hardiest members of the species can live to be 2,000 years old.
Redwoods have gained a prized status among nature lovers, but their high-quality timber has long been favored by home builders seeking the same durability that allows the trees to survive in the wild, which has led to widespread harvesting.
Milarch said coast redwoods can reproduce themselves through a natural cloning process and by mating with other trees. A tree like Grandma could effectively be the latest incarnation of an individual tree that first saw daylight 20,000 years ago, he said.
“If we're going to pick out the strongest, longest-lived genetics, this old gal's a survivor,” Milarch said.
Horticulturists and genetic engineers plan to use the samples from the Marin County redwoods to see which of several techniques – some traditional, some cutting-edge – work best to reproduce the trees.
Milarch has high hopes for the most advanced approach, known as tissue culturing, which creates exact genetic replicas by manipulating individual cells.
Not everyone agrees that cloning represents the most effective way to preserve redwoods. Conservation groups have traditionally focused on curbing development and logging along the 500-mile stretch from Big Sur to the Oregon state line where most coast redwoods grow.
“Protecting the habitat of the species in place – I think that's the most important approach to conservation,” said Deborah Rogers, a redwood geneticist and director of conservation science for the San Diego County-based Center for Natural Lands Management.
Rogers said a genetic storehouse that could protect the entire species from an unforeseen cataclysm caused by climate change or an imported disease would require samples from hundreds of trees across the state.
Milarch hopes that samples from about 20 individual trees taken from ancient redwood stands in five distinct areas will be enough to get his restoration effort under way. Next he plans to solicit landowners and communities for plots of at least five acres where the clones will be planted and, ideally, interbreed.
On the Web:
Champion Tree Project: http://www.championtrees.org