The Mystery of the Poisoned Trees: Unhappy Ending Seen

It would be the quintessential El Cerrito mystery story except it’s missing the part at the end where the sleuth explains whodunit and the culprit is hauled off to jail.

About two years ago, someone removing brush for the city to reduce fire risk in the noticed some sickly-looking coast live oaks near the trailhead by Regency Court.

“I was asked to come and see why they were declining,” explained consulting arborist Steve Batchelder Thursday as he visited the knoll with Bill Driscoll, city public works superintendent, to check on the health of the trees.

Finding no natural explanation, he began to dig around the base of a tree and discovered a hole had been drilled at its base. Continuing his search, he found 11 trees each with a hole drilled in it, many of which had been plugged with a cork.

"This is a strong indication that the trees may have been poisoned, since no signs of common pathogens or insects were found on the trees," Batchelder wrote in an August 2009 report to the city.

Police were called in. Working on the assumption that the dirty deed was done to give someone a better view, officers visited Regency Court and Kent Court, just uphill from the poisoned trees, to see who might benefit from the death of the trees and to interview residents, according to Lt. Paul Keith.

Police collected samples of the corks and were able to match them to a Healdsburg craft winery called Papapietro Perry Winery. They got a list of some of the regular customers, but none lived near enough to the trees to benefit from their demise.

A leaf was sent off to a lab for analysis in hopes that it would provide information about what was used to poison the tree, Keith said. But it yielded only general information about the chemical and the news that it would be costly to try to narrow the identity of the herbicide any further.

Ultimately, police were not able to come up with enough evidence to proceed, and the case is no longer active, Keith said.

As he examined the trees Thursday, Batchelder said they show some signs of life but probably won’t recover.

“The problem is their energy system is broken.”

In addition to the expense of lab work, Batchelder cited the passage of time before the poisoning was discovered as a problem in identifying the herbicide used.

For Batchelder, who would still welcome an anonymous tip identifying the poison, the information would provide some understanding of exactly how the trees’ systems are being disrupted and possibly offer guidance on what steps to take.

In addition to the direct damage caused by the unknown herbicide, he said, the weakened trees are left more susceptible to attack from such enemies as the Ambrosia beetle and fungal leaf blight.

While healthy trees are naturally fire resistant, Batchelder said, the damaged ones could present a fire danger, compounded by the fact that French broom is taking over under the trees because they aren’t dropping many leaves.

Batchelder said one possibility would be to remove all of the trees, or at least the ones that are in the worst shape, cover the area with mulch and plant acorns or seedlings. The problem with putting in more mature oaks, he said, is that they don’t come with root systems proportional in size to the tree and are therefore less likely to survive.

Also, because the culprit was not caught, the city would have to bear the cost of whatever work is done. Driscoll said for now the city will probably remove the dead limbs and low vegetation and continue to monitor the trees’ progress.

Driscoll called the case a “pretty isolated incident.” Batchelder said he sees something along these lines every couple of years in his work, but the last case in El Cerrito he recalls was about 20 years ago.

“Trees are beautiful. Some people don’t understand that,” Batchelder said.

Complaints of neighbors damaging or removing each other’s trees are more common than reports of attacks on trees on public property, Keith said, but those are usually a civil matter for the neighbors to resolve and don’t prompt criminal investigations.

Had a culprit been caught, he or she could have faced felony vandalism charges that carry a one-year state prison term or a $10,000 fine. The culprit also could have been forced to pay restitution.

 “I hope we at least put somebody on notice that their activity has not gone completely unnoticed,” said Keith. Driscoll noted that the investigation shows that this sort of action is something that is taken very seriously by the city.