Source: Contra Costa Times (Calif.)
More than a dozen stumps dot the Boundary Oak Golf Course where trees once grew, marking the death of Monterey pines, eucalyptus, black walnut and other trees from bug infestation, old age or stress.
Bark beetles have killed several Monterey pines at the 35-year-old golf course, while an Australian pest has attacked eucalyptus trees.
Others, including several black walnut trees, have reached the end of their life spans or have fallen victim to the harsh environment created by compacted soil, densely planted trees and golf balls battering their bark.
City officials say the trees will be replaced, although how many and when depends on funding.
Golfers said Friday they value the more than 1,500 trees at the course, which is named for its many oaks. Dick Warrender and Walt Rogers of Concord said the trees are what make the course beautiful and appealing.
"If they're dying, they've got to take active steps to replace them," Rogers said.
On the 10th hole, where several stumps were visible, 17-year-old Northgate student Kramer Chan said he has noticed several trees dying recently. While he admitted trees sometimes block his shots, he said they give the course character.
"They really create a sense of age," he said.
Although errant golf balls are not a problem for most trees, bugs and stress are common throughout the county at this time of year, and age takes its toll after about 20 years, said several tree experts.
Ips and red turpentine beetles infest trees that are weak or have recent cuts or damage, said city arborist John Davis.
Larvae from ips beetles and from red turpentine beetles kill Monterey pines by eating their way around the trunks.
"It's like if you strangled something," Davis said. "They cut off the supply of water and food the tree needs, so the tree goes from green to yellowish to reddish-brown color."
Spraying is not effective, because ips beetles attack the entire tree, Davis said. Red turpentine beetles, however, can be killed by spraying because they only attack the trunk.
To eradicate the beetles, Walnut Creek landscape maintenance workers are chopping up dead Monterey pines at the city-owned golf course, then sending branches through a wood chipper. Wood chips dry out quickly and are not attractive to beetles, Davis said.
He peeled back the bark of one tree, revealing a host of wiggling, wormlike larvae.
"It looks like rice cooking," said city field arborist Chuck Gedney.
The trunks now dotting the golf course will be dug up and then buried to prevent the larvae from growing to adults that can fly to other trees. Workers removed 16 trees in September and are taking out 13 more this month.
Many black walnut trees, including those at the golf course, were planted in orchards that dominated the Ygnacio Valley before subdivisions sprang up. These trees are reaching the end of their life cycles, said arborist Tim Ghirardelli, who created the golf course's tree management plan.
He suggested that the city create a nursery at the golf course and grow trees to replace those being removed. Davis said he wants to plant up to 100 cedar, oak, redwood and other hardy trees.
"The golf course relies on trees as barriers between fairways," he said. "If it's wide open, balls will be flying all over. Trees provide a challenge."
