02/23/93
CONTACT: Stanford University News Service (650) 723-2558
STANFORD -- One of Stanford's largest and most spectacular oak trees - the spreading giant next to the Stanford Family Mausoleum - is dying and will be cut down in March.
The heritage tree, estimated to be 300 years old, has been in steady decline for about seven years and now is structurally weak, according Herb Fong, manager of grounds.
Bacterial organisms have infected the coast live oak (Quercus agrifolia) with diplodia, a disease that causes branches to die, and cryptocline, which kills individual leaves.
"It's really significant when we lose a tree this large," Fong said.
Retired Palo Alto city arborist George Hood said the tree is "noteworthy for the size of its crown structure and crown spread."
"It has shared itself with the history of Stanford University," Hood said.
Legend has it that the tree was a favorite of Leland Stanford Jr., but no documentation can be found to verify that.
Leland and Jane Stanford may have considered the grand oak when they picked the location for their granite and marble mausoleum. That selection ultimately may have contributed to the oak's decline.
After approximately 200 years in a wide-open field with wet winters and dry summers, the oak was forced to adjust when asphalt was laid over a major portion of its roots, blocking rain water and soil aeration. The rest of the roots were covered with lawn and other landscaping that needed off-season irrigation. Before the access road was blocked a few years ago, countless car owners parked under the tree, compacting the roots.
Fong speculates that recent drought-related stress made the tree more susceptible to disease.
His crews will remove the tree in late March. The date and time will be announced for those interested in watching.
Perhaps because of its location next to the Stanford tomb or just because it is so spectacular, the huge oak has been the object of much care and affection by campus arborists and horticulturists, from cables added in the early 1930s to Fong's recent efforts to save it.
Several years ago, his crews sprayed the immense tree with the fungicide Benlate, which some studies showed would help control diplodia and cryptocline. Unfortunately, it didn't work.
In an effort to counter the negative effect of the asphalt, grounds crews drilled holes through it and installed perforated PVC pipe for deep-root watering and feeding. That may have prolonged the tree for a few years, Fong said.
Old age also must have been a factor in the oak's decline. A count of tree rings in the trunk - if the core proves free from rot - eventually may yield a close guess of the tree's age, but in the meantime Fong estimates it sprouted in the late 1600s at least.
Certainly, it was alive at the nation's founding. During the bicentennial, the National Arborist Association and the International Society of Arboriculture installed a plaque nearby that the behemoth was alive at the signing of the U.S. Constitution.
An examination of records in the University Archives reveals sparse information about the tree. Photographs taken in 1931 show that a series of cables had been installed to hold up the heavy limbs, and one guy wire anchored the tree to the ground.
Nevertheless, a severe storm knocked over the giant sometime during the early 1930s.
In notes about Stanford trees dated 1979 and deposited in the Archives, the late campus grounds superintendent Dirk Schroder wrote that the mausoleum oak fell in a storm after 10 to 20 feet of branches had been removed and steel cables had been installed and connected to large blocks of concrete in the branches. Stanford graduate Frank Nolan, class of '28, did the 1931 cabling and branch thinning, according to Schroder's notes.
Fong said timing of the toppling was coincidence, not caused by Nolan's work. Nolan and others, Fong said, were simply trying to pull up branches that had a natural tendency to sweep the ground, thereby preventing the long limbs from breaking.
The tree was jacked up after the storm, but workers apparently couldn't push it all the way. Examining one of the 1931 photos, Fong noted that the trunk was never as vertical after its big fall as before. Additional anchor guy wires were installed when the tree was righted.
Fong said that for years, a grounds superintendent would drive his truck under the lowest major limb. If it scraped the roof, workmen would add more cables.
But, ultimately, excessive cabling weakened the tree, Fong said.
"Cables weaken a tree because the branches fail to develop their own strength - they rely instead on the steel," Fong said.
As an example, Fong said that several of the tree's limbs are larger in diameter outside or beyond their cabling point - a sign that the end of the branch developed appropriate strength to hold its weight, while the inner portion failed to develop because it relied on the cable.
Fong, then a recent horticulture graduate of the University of California-Davis, joined the staff as grounds manager in 1973. In the late 1970s, he ordered the "sacred" lower limb cut off as part of an effort to decrease the tree's weight and mass, and reduce the need for more cabling. His crews also pruned back the ends of branches, watching whole limbs move upward as they reduced the weight.
Fong and his crews care for about 30,000 trees - 20,000 on the main campus and another 10,000 in the arboretum - not including trees in the foothills, the faculty-staff housing area, the research park or the shopping center.
Thirty-three of those 30,000 trees measure 55 inches or greater in diameter at breast height - the measurement standard for tree diameters. Most are the fast-growing Tasmanian blue gums, Eucalyptus globulus, the giants of the arboretum and what remains of the tree-lined Governor's Avenue.
The two oaks on the exclusive list are the mausoleum oak and the oak in the front yard of Hadley and Gladys Kirkman's home at 623 Cabrillo Ave., across the street from the Lou Henry Hoover House lawn.
Coast live oaks are slow growing, usually reaching a maximum height of about 70 feet. The mausoleum oak is 70 feet tall, with a branch spread of 120 feet. Blue gums grow 150 to 200 feet high, and often only live about a century.
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