Dutch Elm Disease Alert

Berkeley has a serious Dutch Elm Disease problem. Trees have already been removed from the 900-block of Fresno Ave (between Marin and Solano), Acton, Dohr, and Russell. Eight more on the 900-block of Fresno alone are scheduled for removal late this fall. More trees are currently marked for removal on El Dorado, Acton, Dohr, and Russell streets. Others are probably marked that we don't know about. There are more than 900 elms in Berkeley.

Dutch Elm Disease, which is caused by an incurable fungus, has already wiped out most of the elm trees in the United States. The disease disrupts the tree's ability to transport water to infected limbs, which soon die of thirst. The first signs of DED are yellowing of individual branches, followed by wilt, then complete death. A tree can die in a single summer after infection in the spring. Once a single tree in a stand gets DED, it infects adjacent trees through their interconnected root systems. This process, known as root grafting, typically marches down a street at the rate of one or two trees per year.

The fungus is carried by the European elm bark beetle, which burrows under the bark to lay its eggs. Its egg galleries then become breeding sites for the fungus. When the eggs hatch, the young beetles fly away, carrying the disease to other elms as far away as five miles. The beetles are active from mid-March through October, but are feeding most vigorously in April. Elm trees must not be pruned during this period because the sap exposed by the pruning attracts the bark beetles like a magnet.

The disease is also spread through infected pruning tools. The California Department of Forestry and the city of Berkeley have suspected for some time that PG&E's pruning crews don't disinfect their pruning tools between trees and do not follow guidelines for pruning dates.

PG&E's "arborists" (Davey Tree) pruned the trees on the east side of Fresno Avenue in late April of '97. All but two of these trees are now sick-six of them are targeted for removal. It is reasonable to suspect that PG&E has pruned elms in other parts of the city during the most dangerous time. To find out the date your elms were pruned by PG&E, call John Hawkridge, Senior Consulting Forester for PG&E at 510 437-2891. Get the dates for the past three or four years.

Under pressure from the residents of Fresno and El Dorado, the City is investigating a lawsuit against PG&E to recover the costs of large replacement trees on those streets where the disease was introduced by unprofessional pruning practices. The neighborhoods are also insisting that PG&E pay for the undergrounding of utilities to mask utility lines that become prominent when the elms are removed. This is a city-wide issue, so other neighborhoods are invited to join in this fight. If you would like more information about Dutch Elm Disease in Berkeley, please contact: Joe Campbell () 945 Fresno Berkeley 94707 A Web page at www.campbells.org is devoted to this issue.

Prevent The Spread Of DED In Your Neighborhood

From mid-March through October, start a neighborhood watch for PG&E's tree pruning crews. If you find them, you must stop them. Here's how:

1. Inform the crew that they are not authorized to trim the trees and that you are calling the police.
2. Call the Berkeley Police immediately and report a "heated dispute" with a tree-trimming crew.
3. While waiting for the police to arrive, do whatever is necessary to prevent the crews from working on your trees. Standing under the tree should be enough.
4. When the police arrive, tell them that untimely pruning of elms is not authorized under City Ordinance 12.44. The police can phone the Forestry department at 644-6566 for verification. If necessary, a City forester will come to the scene.
5. Note the license number of the crew's truck and the crew chief's name. Report this to the City Forestry department.

There are approximately 900 elm trees throughout the city, but here is a list of the streets with the highest concentrations: