A 100-plus-year-old heritage oak tree at 816 Cowper St. in Palo Alto that had been slated for the chopping block may be saved, officials have announced.
Public Works staff met with neighbors and tree supporters Wednesday afternoon to outline plans to save the venerable oak, nicknamed "George," from the chainsaw.
Arborists plan to remove three to four tons of limbs to help redistribute weight that is threatening to topple the tree, Public Works Director Michael Sartor said.
"Under normal circumstances, we would never take off this much. It needs extraordinary measures," said Dave Dockter, a city arborist.
The tree was considered a liability after arborists discovered a fungus had eaten out all but 6 inches of the heartwood on the 13-foot-circumference tree, Dockter said.
Despite the expansive and healthy canopy, the tree's structural integrity is precarious, he said.
"It's as thin as a pipe. The tree is hollow about 8 to 10 feet up. It's like an eggshell," he said.
The oak's outer layers of wood form a protective shell, through which the tree continues to get nutrients that keep it healthy. But the arborists were concerned the weight could cause the trunk to crack, and the tree could come crashing down, he said.
Sartor said public works staff decided to give the tree a second chance. On Wednesday he ripped the two tree-removal signs down.
Carol Kiparsky and Ian Irwin have lived in their home beneath the oak's canopy for 16 years.
"It's a very important tree," Irwin said.
The couple has only seen one larger that rivals George -- on the Coal Mine Trail in Portola Valley, they said.
Catherine Martineau, executive director of Canopy, said the tree is a remnant of the original Palo Alto.
"This area was an oak-studded savannah. These are the real trees of this area. The city has a particular connection to these types of trees," she said.
A 1991 survey found that about 9,000 native oaks inhabited Palo Alto's urban area.
"It would be interesting to do that survey now and see what's still here," she said.
Eugene Segna, interim public-works arborist, said workers would remove asphalt from around the tree's roots on Friday (Sept. 30).
On Monday (Oct. 3) arborists will do a root-crown excavation to evaluate the tree's health and assess how long it might be able to stand.
If the roots are not diseased, crews will start removing several major limbs on Tuesday.
Crews will also look at cabling and any supports that need to be added, he said. After that, the tree will be monitored and residents will be notified each time.
"In addition to this particular tree, the urban-forest group will be evaluating other heritage trees in Palo Alto that need similar attention," Sartor said.
That process would be incorporated into the Urban Forest Master Plan the city and Canopy have been working on for the last couple of years, he said.
Segna said it is hard to categorically state the life span of the trees. In most urban settings, it is usually 50 years, due to environmental impacts.
Most detrimental to the Cowper oak is damage from parking vehicles. The tree juts out into the roadway, a remnant of when the city still had dirt lanes, Dockter said. The damage allowed the fungus to get started, he added.
Martineau said she is glad the city is taking the time to help residents understand the tree's condition and complexity. She stressed that Canopy is not in a position to make an assessment.
"We rely on the city's experts. We have good arborists," she said.
Dockter said the department has had some requests from residents to obtain a special piece of the tree. One woman plans to have a friend make a bowl.
The arborists and crews are looking forward to the challenge of pruning the old tree. They even have a wager going regarding the weight of the branches that will be trimmed off, he said.
"We have bets. The guys are so excited to do this type of cutting. Roughly shooting from the hip, I've determined that about 3.8 tons -- 7,546 pounds -- will be taken out.
"When we prune the tree we'll load up the truck and go by the scales and see which climber comes closest," he said.