Bringing Back the Napa Valley shade: Leah Garchik on the Napa Historical Ecology Atlas

On lands where mighty oaks once grew, mighty oaks may grow again. That's the optimistic view of environmental scientist Robin Grossinger of the San Francisco Estuary Institute, whose new book (with cartographer Ruth Askevold) is "Napa Valley Historical Ecology Atlas: Exploring a Hidden Landscape of Transformation and Resilience."

The oak savanna of the Napa Valley landscape was always a "peculiar combination of large trees and open meadows," writes Grossinger. In the 19th century, the oaks, as written about by Robert Louis Stevenson and photographed by Eadweard Muybridge, "lent a sense of grandeur and beauty to the landscape that was widely appreciated, even as the trees declined."

But from about 1860 to 1910, as ranchers, vineyards and orchards took over the valley, most of the trees disappeared. There are exceptions: Nowadays, some survivors are as old as 500 years.

A hundred years after the trees were cut down, they may be coming back, as the terrain is "re-oaked" by people planting trees while others sprout along roadsides and in people's yards.

The Napa Valley "is still a very viable area for the tree," said Grossinger in a phone conversation. "If people make a concerted effort, they really could be brought back in a significant way."

Grossinger cited the beauty of the trees, and their utility, not only as part of the ecology, but also as providers of shade for workers. Among county staff and vineyard managers, "There is a lot of support for this possibility of re-oaking," he said. The valley won't ever again have as many oaks as were once there, "but you could bring back a lot of the elements, while maintaining the valley as we know and love it. In some way, what makes Napa unique is these grand trees. You see them on wine labels often. I think they're definitely part of the heritage of the valley and we are recognizing that."

Grossinger speaks today at Mrs. Dalloway's Books in Berkeley, and April 19 at the Oakland Museum.