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These pines near the heavily traveled Albany intersection of San Pablo Avenue and Buchanan Street are leaning dangerously, kept from falling over only by neighboring trees. (Jonathan King photo)
 

Campus to remove diseased Monterey pines from Gill Tract in Albany
Infection, pests, and high winds have all taken their toll on the aging stand of trees, posing danger to the driving and pedestrian public

| 23 January 2008

A stand of diseased Monterey pines will be removed from the campus's Gill Tract property in Albany beginning Monday, Jan. 28. A majority of these pines are infected with pitch canker, a fungal disease that weakens susceptible trees, leaving them vulnerable to fatal infestation by bark beetles.

Removal of the stand was decided upon because the 184 trees identified as sick in the first phase of this two-phase project pose a public-safety danger. Campus arborists have determined that a significant number of the diseased trees at the Gill Tract - many of them planted in 1963 as part of a research project and nearing the end of their natural lifespan - are at risk of toppling over. Those within a Monterey pine's height of the property boundary are at risk of falling onto public streets and sidewalks. Numerous trees within the stand exhibit significant leaning, and a number have already fallen; it is only a matter of time until they all fall, campus arborists say.

The stand, located at the northeast corner of the property, abuts heavily traveled streets near the corner of San Pablo Avenue and Buchanan Street. The property is fenced, but there is concern that trees as far as 70 feet from the fenceline could topple - whether from the effects of disease, or from high winds like those that recently blew through the East Bay - striking cars or pedestrians passing by.

Arborist Phil Cody, the ground-services manager with UC Berkeley's Physical Plant - Campus Services unit, first noted the prevalence of pitch canker in the Gill Tract stand last year. He estimates that 65 to 70 percent of the Monterey pines in the affected stand currently show symptoms of the disease, which primarily infects pine species along the California coast. The canker weakens the trees, which then become more susceptible to colonization - and further weakening - by bark beetles. Uninfected trees are in jeopardy of infestation because their diseased neighbors support growing populations of the beetles. Removal of diseased trees is the only effective method of dealing with the beetle infestation.

Cody, in consultation with campus landscape architect Jim Horner and UC forestry specialist Brice McPherson, evaluated each pine tree in the stand, assessing its failure potential, the size of the trees or branches at risk of falling, and the likely danger to people and property should they fall. They determined that 184 of the stand's 317 pines, several of which are already dead, should be immediately removed. In response to a growing concern that the remaining trees, no longer protected from wind, would then be dangerously exposed, it was decided that those trees should be removed as well.

The tree removal will take place in two phases. Phase One, beginning Jan. 28 and lasting for approximately two weeks, involves the removal of those trees that, due to their proximity to public roadways and sidewalks, pose the greatest immediate safety hazard. The open space created by the removal of trees in Phase One will be seeded with wildflower and grasses for aesthetic purposes.

Timing of the project's second phase has not yet been determined.

The other species - including cedar and other pines as well as palms, redwood, eucalyptus, and mulberry - that share the Gill Tract with the at-risk and infected pines will not be removed. Potted oak saplings currently on site as part of a project being conducted by Sudden Oak Death researcher Matteo Garbelotto will be moved to another portion of the property.

The cost of the two-phase removal project will be $54,000. Campus officials emphasize that the removal has nothing to do with proposed development of campus-owned property nearby, which has yet to be approved by the city of Albany.

Questions and answers about the tree-removal project, as well as photos of the project site showing fallen trees and damage caused by pitch canker, are online at www.cp.berkeley.edu/CP/Projects/GillTract/HazardousTreeRmvl.html.