University of Iowa to remove 10 trees from Pentacrest

IOWA CITY - With most University of Iowa students away for winter break, crews next week will begin removing 10 diseased or damaged trees on the Pentacrest, several of which 'pose a threat to public safety.”

The trees, including nine ash trees and one oak tree, are being removed for a variety of reasons, including fungal disease, cracks in the limbs and wounds to the base that have weakened them to the point of threatening public safety, UI officials said.

Most of the targeted ash trees are on the southeast quadrant of the Pentacrest, although one sits north of Macbride Hall along Jefferson Street, and another is near the Madison and Washington streets intersection.

The single oak tree sits west of Jessup Hall, and Noel's Tree Service - based in Iowa City - will remove it via crane next week, university officials said. Several of the trees line some of the university's most heavily used sidewalks.

The work, which is expected to take a couple of weeks, is part of the UI's 'regular tree care and maintenance.”

Crews will plant new trees in their places - likely next fall - allowing the university to maintain 178 trees of varying species on its Pentacrest.

The UI's Landscape Services 'tree care team” maintains more than 8,000 trees of 250 species, and it typically plants more than 300 trees a year, according to a UI news release. The goal, officials said, is to replace every removed tree with two.

The ash trees slated to come down are not being removed because of threats from the emerald ash borer, and the university has no plans to 'start wholesale removal of ash species on campus.”

'We also will not be treating any of the ash with insecticides due to long term costs and questions about environmental impacts,” according to a UI news release.

Although the university has been using wood chips to help power the campus for a year now, officials said the damaged and diseased trees won't make it into the boilers.

That is an eventual goal - one the UI Office of Sustainability had hoped to reach sooner as part of its push to achieve 40 percent renewable energy consumption on campus by 2020. But Ferman Milster, principal engineer of renewables for UI facilities management, said wood chips have to be a certain size, and few machines can accomplish that.

'One of the lessons we have learned is that if you don't have them to a certain size, it's going to cause problems,” Milster said.

The university in March tried to use timber that had been downed in a wind storm, but Milster said those chips 'actually broke a chain in our conveying system and forced some repairs.”

'And we have to have those units running this time of year,” he said. 'So we are not going to take any risks.”

Wood chips the university uses as fuel are processed out of Muscatine, and Milster said the campus is working to produce larger volumes of wood at the size it needs.

'But it is not available today for projects like this that come up,” he said.

Instead, the downed trees will be taken to a log salvage yard, where crews will look for uses beyond mulch, said Andrew Dahl, UI campus arborist.

'Hopefully, some day, the power plant will be able to use our wood waste,” Dahl said. 'Until that time, we are holding on to them.”